E30 M3 minor rust repair (few finished pic's)
Moderator: martauto
Evenin all,
Thanks again for all your kind words, much appreciated
As mentioned in the last post we're taking a break from the shell
for a while and moving on to the drive train overhaul, and, starting at
the back and moving forward, first up we have the differential. That
magical lump of metal that sits in the back axle and lets you move
in a sideways fashion when the opportunity arises.
First and foremost, as usual, we'll just take a second to say the
obvious, this isn't a guide on how to build a diff, for that, go here
http://bmw.ctcms.net/BMW/Software/E30%2 ... %20e30.rar
(password to unzip the files is bmwfaq )
download the full workshop manual and follow the smart people
at Bmw's guide, The section on the diff starts at 33-101.
Unfortunately they don't use a large selection of hammers to do
their overhaul, so I have trouble relating to it.
Anywho, back to my diff. This is a medium case diff as identified
by the 8 bolts that hold on the back cover, the small case diff
has 6 bolts holding on the rear cover and the large case diff is
easily identified by snapping your spine while trying to lift it as
it weighs 14 ton.
First up pop the 8 bolts off the rear cover and remove, spilling the
remaining horrible smelling diff oil over your clean bench.....
then using special tool no. 959bigbar, we popped out the halfshaft
flanges....
in the middle of the diff that big gear you can see is the crownwheel
and to the right of it is the limited slip differential.......
and next up was the crownwheel bearing cups. One on each side of
the diff and these house the crownwheel bearing outer races which
hold the diff unit in place. Theres a ring of six bolts that hold each
one in place, and before you undo them it pays to take a second to
notice that each cup has a square notch on top of them (as arrowed)
which alligns with a corresponding notch on the diff casing (as arrowed)....
When you undo the ring of bolts and pull out the cups the diff unit
will drop inside, so you can either let it drop and damage it or put
your hand under it and damage it instead. If your lucky enough to
have an assistant helping you then you'll not need me to tell you who's
hand to use. When you pull the cups you'll notice a shim (arrowed),
this will either be still stuck to the casing or the cup. Keep these shims
matched with the cup they were fitted with and mark which side they
came off, they'll need to go back on the same side or things will start
to get funky. When the cup's off you can see why it has a notch to
show you why it needs to be fitted this way up. In the pic bellow
you can see the cup has an oil drilling (arrowed) which lets oil splash
in the top of the cup and drip down on to the crownwheel bearings, and
obviously if you fit the cup any other way the oil aint going to drip anywhere....
With the crownwheel/diff unit carefully lifted out all thats left in the
casing is the pinion......
to remove this you gotta take the pinion flange off the front of the
pinion....
first up bend back in the little piece of the locking washer from the
recess to let the nut loosen.....
and then use special tool part no.959rustypieceofbar....
which is basically a piece of bar with holes drilled into it to allow
2 M8 bolts to fit through it and bolt up to the pinion flange and hold
it from turning while loosening the nut....
once the nut's off, the flange should lift off, if it doesn't smack it repeatedly
with a large hammer while searing at it loudly, it won't come
off any easier but I find you'll feel better.....
pop the nut back on to protect the threads from stray hammer blows,
it turns out fine threads and large hammers do not mix,
I know, it suprised me too....
pry out the pinion seal.....
and then strap on a pullers and push out the pinion.....
(I know the pullers is crooked, if it really bothers you, tilt your head
to the side)
and bingo, one pinion and a front and rear pinion bearing and
although its hard to make out in this pic, also a collapsible spacer ....
If your diff has started to whine, rumble or make strange noises then
usually it's these bearings that have started to sh*t themselves. Everytime
you drop the hammer in your car and unleash all that horsepower it's this
pinion gear that try's to burst it's way out of the differential casing and these
two bearings that have to persuade it to stay.
next up is to strip out the bearing outer races starting with the pinion pair
in the diff casing. The inner pinion bearing race drives out down into
the casing and flip it over and the outer race drives out through the top...
the two races out and the next thing to make a mental note of, is the
inside race has a shim between it and it's seat in the casing(arrowed).
This has to go back in to the same spot upon reassembly or again
things will get funky....
next up the crownwheel cups, drive the oil seals outwards.....
and flip it over and drive the bearing races out....
With everything stripped down it's time for clean up. As you
can see below the casing was covered in a fine blend of crap
and rust.....
So we break out the "de-scaler", as usual I've no idea what the rest of
the world calls this tool. It's air operated and when you pull the trigger
all them little needles plunge up and down pounding the crap out of
whatever you happen to be holding it against.
It does a fine job of removing all the loose crap and rust from the
casing and then proceeds to evenly spread it around the rest of the
garage while deafening you in the process.....
casing cleaned, it gets a coating of red oxide, before a final coating
of satin black....
the rear cover (which I think is a Z3 item with the extra cooling fins)
gets a steam clean. One bit that gets a little special attention is the
little breather hole. Gotta make sure this ain't clogged up, as if it is,
when inside the diff gets hot theres no where for the expanding warm
air to get out and it ends up pushing oil out past your lovely new
seals...
after that it's on to pulling off the crownwheel bearings, these little
fu*kers were tight and needed the use of the bigger pullers....
the other little thing to be careful of is the thin trigger wheel
shown below pressed on to the diff unit. Its the trigger wheel
that the speedo sender reads to tell the speedo gauge up
on the dash how far over the speed limit your going. As it's
thin, it'll bend easily and if your unlucky you'll reassemble everything
only to find out your speedo no longer works, which will mean stripping
everything back down again and repairing or replacing it, which is nice.....
after that, it was on to pulling the pinion inner bearing. To say this was
tight really doesn't convey it accurately, b*stard tight would be
a better discription. One of those one's where you strap the pullers
on and start winding, and winding, and winding, and then stop, and
rap rags around the bearing in the misguided thought that if the bearing
explodes they'll save you from harm, while the truth being that if it does
go you'll now have bits of dirty rag stuck in you along with bits of bearing....
and eventually theres a large crack and after you check for
shrapnel wounds you realise the bearing has started to come.
(mental note, must look into health insurance.)
Then with everything stripped down it's on to the "decontamination unit"....
Two basins of paraffin, one to wash the heavy crap off and the second
to rinse the smaller stuff off and then finally aerosol cans of parts cleaner
to give them the final rinse.
With that done it's on to setting up a clean area to place the parts
on once their washed.....
Below is a picture of everything and a list of what we've chosen to replace
(unfortunately the forum won't allow a big picture
so if you click on it, it should open in another window slightly
larger and easier to see).....
(red font is the changed parts)
1. Pinion flange
2. Pinion
3. Pinion nut lock ring (oe) 23 21 1 490 120
4. Pinion nut
5. Collapsible pinion spacer (oe) 33 12 1 744 368
6. Pinion seal (oe) 33 10 1 214 099
7. Pinion shim
8. Pinion inner bearing (aftermarket)
outer race- SKF fk-hm 89410-2-cl7a
bearing- SKF ak-hm 89449-2-cl7a
9. Pinion outer bearing outer race (aftermarket)
SKF fk-h 88510-2-cl7a
10. Pinion outer bearing (aftermarket)
SKF ck-hm 88542-2-cl7a
11. Crownwheel bearing cup shim
12. Crownwheel bearing cup O ring (x2) (oe) 33 11 1 214 144
13. Halfshaft flange
14 Crownwheel bearing cup
15. Crownwheel bearings (x2) (aftermarket)
outer race- SKF fk-lm 503310
bearing- SKF k-lm 503349-cl7a
16. Halfshaft flange seals (x2) (oe) 33 10 7 505 602
(comes with part 17's included)
17. Halfshaft lock rings (x2) (oe) (comes with above)
18. Limited slip differential and crownwheel
19. Casing
19. Casing gasket (oe) 33 11 1 210 405
20. Speedo sender locking plate
21. Speedo sender and O ring
22. Z3 rear cover
In the list above the renewed parts listed in red and are marked
(oe) for bought off BMW, or (aftermarket) for sourced
at a local bearing supplier. The bearings sourced "aftermarket"
are either SKF or KLM bearings which is exactly what you'll
get from Bmw, only they won't come in a nice little Bmw jiffey
bag, but they will cost less than half the main dealer price.
With everything together it was time for reassembly. I've taken
the decission not to open up the limited slip diff unit as before
the car came off the road it was working perfect, and I know
if I open it I'll start replacing things, and, well, that money can
be better spent elsewhere.
Beer.
First up on the list of reassembly is to press on the crownwheel
bearings.....
then fit the races for these bearing into the crownwheel cups....
flip the cup over and pop in the halfshaft seals. The seal goes in till
it butt's up against the back of the bearing race(arrowed)....
One thing to be careful of is when driving in the seal up
against the back of the bearing race, is, if you go a little to
far you can possibly knock the bearing race back out a bit.
So, when done the cup is flipped over again and the race is
tapped back in again to make sure it's home.
Then on to the pinion bearing races. First up the inner bearing race.
This was the one that had the shim under it, so, shim dropped in
first and then bearing race popped in on top of it....
then flipped over and the outer race fitted....
With all the races refitted the next thing to be done is pop back in
the diff unit and refit the cups and shims(arrowed) remembering
to keep them to the sides they originally came out of....
with the cups bolted back in tight both sides it's time for the first
setup check. The cups should now be holding the diff unit tightly,
it should be able to rotate but have no noticeable play in the direction
of the arrows below....
and aswell as having no play the cups should also be slightly squeezing
the diff bearings which is known as preload. This preload is measured
by a special tool which basically bolts on to the halfshaft flange and
measures how much effort it takes to rotate the crownwheel. To little
force, remove some shims which tightens up the preload on the bearings
when the cups are refitted. To much force required to turn it and
you pop in the next size up shim to ease off the preload.
There is figures given for it in the workshop manual.
If all you've changed in the overhaul is bearings and everything else is
original to that casing going back together then odds are the shims
that were there already will be fairly spot on.
If you've built a lot of diff's there's another special tool you can use to
measure the preload....
With all that done, we pop the crownwheel and cups back off again,
and start fitting up the pinion. First up drop in the outer pinion
bearing.....
followed by the seal.....
and then the inner pinion bearing is pressed on to the pinion shaft
and then the colapsable spacer(arrowed) is dropped on as well.....
this lot is then pressed into the casing and up through the outer
bearing. The pinion flange is popped back on and special tool
reattached.....
and the pinion nut is retightened.....
Theres no torque for this nut as again your using it to "preload" or
squeeze the two bearings below it just the right amount.
When retightening it you can feel the nut first tighten a little bit as
the outer bearing gets squashed up against the collapseable spacer,
but the pinion still is able to slap up and down in the direction below....
What has happened here is the both bearings have not been squeezed
close enough together yet and they can lift up and down off their races
because that collapsible spacer is keeping them apart.
So, the nut is tightened down more, slowley, crushing the collapsible
spacer till theres no up and down play and the bearings are sitting snugly
in their seats and then ever so slightly tightened again in little steps till the
right preload is got on the bearings. This extra bit of squash (preload)
on the bearings is done because when you nail the accelerator pedal
if the bearings were just fitted loosely they'd start to lift out of their
races and the pinion would start it's break for glory out through the
diff casing. Instead of leaving two nice big black tyre marks you end
up leaving one nice big trail of diff oil and gears.
Again there is a special tool for measuring the correct preload and
the figures for it are in the manual.
With everything tightened up correctly and a quick splash of holy water,
the lock washer is bent in to place....
casing is flipped over and crownwheel unit and cups refitted....
and halfshaft flanges refitted....
And then finally on to the most important check of the lot,
tooth contact. Some engineers blue....
spread evenly on 3 crownwheel teeth.....
and then rotate the diff gears by turning the front pinion flange while
putting a bit of loading on it by holding one of the output flanges loosely....
and what your left with should be a marking on the crownwheel teeth
of where the pinion teeth are contacting it. What your looking for is a
nice fat contact patch in the middle of the tooth, something like below....
If the contact patch is too high up towards the tip off the tooth you'll need
to move the pinion gear closer to the crownwheel by putting a fatter
shim under the inner pinion bearing.
And if it's too low to the base of the tooth you'll need to fit a thinner shim
to move the pinion gear back away from the crownwheel.
If the contact patch is too far towards the inside of the crownwheel tooth
then you've got to change the crownwheel bearing cup shims to move
the crownwheel away from the pinion gear.
And likewise if the contact patch is towards the outside of the tooth
change the cup shims to move the crownwheel towards the pinion
gear.
Again if none of the main components have changed during the overhaul
then the contact patch should be pretty close to right, but you still
gotta check. You can see now why it's important to refit all them
shims exactly where they came from.
If you get the tooth contact patch badly wrong, then don't
worry to much about it, you'll be getting a chance to rebuild it all again
after a few miles, when it sh*ts itself.
After all that mind numbing crap is done, a bit of gasket sealer....
under the gasket and a little smear above....
bolt the rear cover back on....
pop the speedo sender back in with a fresh o ring....
bungs back in and fill with oil and thats it....
and all that waffle was for a case with 2 gears and 4 bearings,
I'm buying a new keyboard for whats coming next.....
till next time....
Thanks again for all your kind words, much appreciated
As mentioned in the last post we're taking a break from the shell
for a while and moving on to the drive train overhaul, and, starting at
the back and moving forward, first up we have the differential. That
magical lump of metal that sits in the back axle and lets you move
in a sideways fashion when the opportunity arises.
First and foremost, as usual, we'll just take a second to say the
obvious, this isn't a guide on how to build a diff, for that, go here
http://bmw.ctcms.net/BMW/Software/E30%2 ... %20e30.rar
(password to unzip the files is bmwfaq )
download the full workshop manual and follow the smart people
at Bmw's guide, The section on the diff starts at 33-101.
Unfortunately they don't use a large selection of hammers to do
their overhaul, so I have trouble relating to it.
Anywho, back to my diff. This is a medium case diff as identified
by the 8 bolts that hold on the back cover, the small case diff
has 6 bolts holding on the rear cover and the large case diff is
easily identified by snapping your spine while trying to lift it as
it weighs 14 ton.
First up pop the 8 bolts off the rear cover and remove, spilling the
remaining horrible smelling diff oil over your clean bench.....
then using special tool no. 959bigbar, we popped out the halfshaft
flanges....
in the middle of the diff that big gear you can see is the crownwheel
and to the right of it is the limited slip differential.......
and next up was the crownwheel bearing cups. One on each side of
the diff and these house the crownwheel bearing outer races which
hold the diff unit in place. Theres a ring of six bolts that hold each
one in place, and before you undo them it pays to take a second to
notice that each cup has a square notch on top of them (as arrowed)
which alligns with a corresponding notch on the diff casing (as arrowed)....
When you undo the ring of bolts and pull out the cups the diff unit
will drop inside, so you can either let it drop and damage it or put
your hand under it and damage it instead. If your lucky enough to
have an assistant helping you then you'll not need me to tell you who's
hand to use. When you pull the cups you'll notice a shim (arrowed),
this will either be still stuck to the casing or the cup. Keep these shims
matched with the cup they were fitted with and mark which side they
came off, they'll need to go back on the same side or things will start
to get funky. When the cup's off you can see why it has a notch to
show you why it needs to be fitted this way up. In the pic bellow
you can see the cup has an oil drilling (arrowed) which lets oil splash
in the top of the cup and drip down on to the crownwheel bearings, and
obviously if you fit the cup any other way the oil aint going to drip anywhere....
With the crownwheel/diff unit carefully lifted out all thats left in the
casing is the pinion......
to remove this you gotta take the pinion flange off the front of the
pinion....
first up bend back in the little piece of the locking washer from the
recess to let the nut loosen.....
and then use special tool part no.959rustypieceofbar....
which is basically a piece of bar with holes drilled into it to allow
2 M8 bolts to fit through it and bolt up to the pinion flange and hold
it from turning while loosening the nut....
once the nut's off, the flange should lift off, if it doesn't smack it repeatedly
with a large hammer while searing at it loudly, it won't come
off any easier but I find you'll feel better.....
pop the nut back on to protect the threads from stray hammer blows,
it turns out fine threads and large hammers do not mix,
I know, it suprised me too....
pry out the pinion seal.....
and then strap on a pullers and push out the pinion.....
(I know the pullers is crooked, if it really bothers you, tilt your head
to the side)
and bingo, one pinion and a front and rear pinion bearing and
although its hard to make out in this pic, also a collapsible spacer ....
If your diff has started to whine, rumble or make strange noises then
usually it's these bearings that have started to sh*t themselves. Everytime
you drop the hammer in your car and unleash all that horsepower it's this
pinion gear that try's to burst it's way out of the differential casing and these
two bearings that have to persuade it to stay.
next up is to strip out the bearing outer races starting with the pinion pair
in the diff casing. The inner pinion bearing race drives out down into
the casing and flip it over and the outer race drives out through the top...
the two races out and the next thing to make a mental note of, is the
inside race has a shim between it and it's seat in the casing(arrowed).
This has to go back in to the same spot upon reassembly or again
things will get funky....
next up the crownwheel cups, drive the oil seals outwards.....
and flip it over and drive the bearing races out....
With everything stripped down it's time for clean up. As you
can see below the casing was covered in a fine blend of crap
and rust.....
So we break out the "de-scaler", as usual I've no idea what the rest of
the world calls this tool. It's air operated and when you pull the trigger
all them little needles plunge up and down pounding the crap out of
whatever you happen to be holding it against.
It does a fine job of removing all the loose crap and rust from the
casing and then proceeds to evenly spread it around the rest of the
garage while deafening you in the process.....
casing cleaned, it gets a coating of red oxide, before a final coating
of satin black....
the rear cover (which I think is a Z3 item with the extra cooling fins)
gets a steam clean. One bit that gets a little special attention is the
little breather hole. Gotta make sure this ain't clogged up, as if it is,
when inside the diff gets hot theres no where for the expanding warm
air to get out and it ends up pushing oil out past your lovely new
seals...
after that it's on to pulling off the crownwheel bearings, these little
fu*kers were tight and needed the use of the bigger pullers....
the other little thing to be careful of is the thin trigger wheel
shown below pressed on to the diff unit. Its the trigger wheel
that the speedo sender reads to tell the speedo gauge up
on the dash how far over the speed limit your going. As it's
thin, it'll bend easily and if your unlucky you'll reassemble everything
only to find out your speedo no longer works, which will mean stripping
everything back down again and repairing or replacing it, which is nice.....
after that, it was on to pulling the pinion inner bearing. To say this was
tight really doesn't convey it accurately, b*stard tight would be
a better discription. One of those one's where you strap the pullers
on and start winding, and winding, and winding, and then stop, and
rap rags around the bearing in the misguided thought that if the bearing
explodes they'll save you from harm, while the truth being that if it does
go you'll now have bits of dirty rag stuck in you along with bits of bearing....
and eventually theres a large crack and after you check for
shrapnel wounds you realise the bearing has started to come.
(mental note, must look into health insurance.)
Then with everything stripped down it's on to the "decontamination unit"....
Two basins of paraffin, one to wash the heavy crap off and the second
to rinse the smaller stuff off and then finally aerosol cans of parts cleaner
to give them the final rinse.
With that done it's on to setting up a clean area to place the parts
on once their washed.....
Below is a picture of everything and a list of what we've chosen to replace
(unfortunately the forum won't allow a big picture
so if you click on it, it should open in another window slightly
larger and easier to see).....
(red font is the changed parts)
1. Pinion flange
2. Pinion
3. Pinion nut lock ring (oe) 23 21 1 490 120
4. Pinion nut
5. Collapsible pinion spacer (oe) 33 12 1 744 368
6. Pinion seal (oe) 33 10 1 214 099
7. Pinion shim
8. Pinion inner bearing (aftermarket)
outer race- SKF fk-hm 89410-2-cl7a
bearing- SKF ak-hm 89449-2-cl7a
9. Pinion outer bearing outer race (aftermarket)
SKF fk-h 88510-2-cl7a
10. Pinion outer bearing (aftermarket)
SKF ck-hm 88542-2-cl7a
11. Crownwheel bearing cup shim
12. Crownwheel bearing cup O ring (x2) (oe) 33 11 1 214 144
13. Halfshaft flange
14 Crownwheel bearing cup
15. Crownwheel bearings (x2) (aftermarket)
outer race- SKF fk-lm 503310
bearing- SKF k-lm 503349-cl7a
16. Halfshaft flange seals (x2) (oe) 33 10 7 505 602
(comes with part 17's included)
17. Halfshaft lock rings (x2) (oe) (comes with above)
18. Limited slip differential and crownwheel
19. Casing
19. Casing gasket (oe) 33 11 1 210 405
20. Speedo sender locking plate
21. Speedo sender and O ring
22. Z3 rear cover
In the list above the renewed parts listed in red and are marked
(oe) for bought off BMW, or (aftermarket) for sourced
at a local bearing supplier. The bearings sourced "aftermarket"
are either SKF or KLM bearings which is exactly what you'll
get from Bmw, only they won't come in a nice little Bmw jiffey
bag, but they will cost less than half the main dealer price.
With everything together it was time for reassembly. I've taken
the decission not to open up the limited slip diff unit as before
the car came off the road it was working perfect, and I know
if I open it I'll start replacing things, and, well, that money can
be better spent elsewhere.
Beer.
First up on the list of reassembly is to press on the crownwheel
bearings.....
then fit the races for these bearing into the crownwheel cups....
flip the cup over and pop in the halfshaft seals. The seal goes in till
it butt's up against the back of the bearing race(arrowed)....
One thing to be careful of is when driving in the seal up
against the back of the bearing race, is, if you go a little to
far you can possibly knock the bearing race back out a bit.
So, when done the cup is flipped over again and the race is
tapped back in again to make sure it's home.
Then on to the pinion bearing races. First up the inner bearing race.
This was the one that had the shim under it, so, shim dropped in
first and then bearing race popped in on top of it....
then flipped over and the outer race fitted....
With all the races refitted the next thing to be done is pop back in
the diff unit and refit the cups and shims(arrowed) remembering
to keep them to the sides they originally came out of....
with the cups bolted back in tight both sides it's time for the first
setup check. The cups should now be holding the diff unit tightly,
it should be able to rotate but have no noticeable play in the direction
of the arrows below....
and aswell as having no play the cups should also be slightly squeezing
the diff bearings which is known as preload. This preload is measured
by a special tool which basically bolts on to the halfshaft flange and
measures how much effort it takes to rotate the crownwheel. To little
force, remove some shims which tightens up the preload on the bearings
when the cups are refitted. To much force required to turn it and
you pop in the next size up shim to ease off the preload.
There is figures given for it in the workshop manual.
If all you've changed in the overhaul is bearings and everything else is
original to that casing going back together then odds are the shims
that were there already will be fairly spot on.
If you've built a lot of diff's there's another special tool you can use to
measure the preload....
With all that done, we pop the crownwheel and cups back off again,
and start fitting up the pinion. First up drop in the outer pinion
bearing.....
followed by the seal.....
and then the inner pinion bearing is pressed on to the pinion shaft
and then the colapsable spacer(arrowed) is dropped on as well.....
this lot is then pressed into the casing and up through the outer
bearing. The pinion flange is popped back on and special tool
reattached.....
and the pinion nut is retightened.....
Theres no torque for this nut as again your using it to "preload" or
squeeze the two bearings below it just the right amount.
When retightening it you can feel the nut first tighten a little bit as
the outer bearing gets squashed up against the collapseable spacer,
but the pinion still is able to slap up and down in the direction below....
What has happened here is the both bearings have not been squeezed
close enough together yet and they can lift up and down off their races
because that collapsible spacer is keeping them apart.
So, the nut is tightened down more, slowley, crushing the collapsible
spacer till theres no up and down play and the bearings are sitting snugly
in their seats and then ever so slightly tightened again in little steps till the
right preload is got on the bearings. This extra bit of squash (preload)
on the bearings is done because when you nail the accelerator pedal
if the bearings were just fitted loosely they'd start to lift out of their
races and the pinion would start it's break for glory out through the
diff casing. Instead of leaving two nice big black tyre marks you end
up leaving one nice big trail of diff oil and gears.
Again there is a special tool for measuring the correct preload and
the figures for it are in the manual.
With everything tightened up correctly and a quick splash of holy water,
the lock washer is bent in to place....
casing is flipped over and crownwheel unit and cups refitted....
and halfshaft flanges refitted....
And then finally on to the most important check of the lot,
tooth contact. Some engineers blue....
spread evenly on 3 crownwheel teeth.....
and then rotate the diff gears by turning the front pinion flange while
putting a bit of loading on it by holding one of the output flanges loosely....
and what your left with should be a marking on the crownwheel teeth
of where the pinion teeth are contacting it. What your looking for is a
nice fat contact patch in the middle of the tooth, something like below....
If the contact patch is too high up towards the tip off the tooth you'll need
to move the pinion gear closer to the crownwheel by putting a fatter
shim under the inner pinion bearing.
And if it's too low to the base of the tooth you'll need to fit a thinner shim
to move the pinion gear back away from the crownwheel.
If the contact patch is too far towards the inside of the crownwheel tooth
then you've got to change the crownwheel bearing cup shims to move
the crownwheel away from the pinion gear.
And likewise if the contact patch is towards the outside of the tooth
change the cup shims to move the crownwheel towards the pinion
gear.
Again if none of the main components have changed during the overhaul
then the contact patch should be pretty close to right, but you still
gotta check. You can see now why it's important to refit all them
shims exactly where they came from.
If you get the tooth contact patch badly wrong, then don't
worry to much about it, you'll be getting a chance to rebuild it all again
after a few miles, when it sh*ts itself.
After all that mind numbing crap is done, a bit of gasket sealer....
under the gasket and a little smear above....
bolt the rear cover back on....
pop the speedo sender back in with a fresh o ring....
bungs back in and fill with oil and thats it....
and all that waffle was for a case with 2 gears and 4 bearings,
I'm buying a new keyboard for whats coming next.....
till next time....
Last edited by x-works on Fri Nov 20, 2009 12:22 am, edited 2 times in total.
that little breather hole ... would it not be wise to run a breather pipe from that to somewhere dry ?
i dont know how much of a concern ittl be for you as i doubt the car will get used too much in the rain (god knows i wouldnt be lol ) but when you drive into a puddle thats a little deeper then you expected after some spirited wet weather driving the diff and oil will be hot and suddenly get cold and suck in whatever is closest to the hole ... air or water so with a breather tube there it would make sure it can only suck in air ..
feel free to correct me if im wrong but just seems like an easy addition that woul dhave no noticeable drawback only a benefit ?
i dont know how much of a concern ittl be for you as i doubt the car will get used too much in the rain (god knows i wouldnt be lol ) but when you drive into a puddle thats a little deeper then you expected after some spirited wet weather driving the diff and oil will be hot and suddenly get cold and suck in whatever is closest to the hole ... air or water so with a breather tube there it would make sure it can only suck in air ..
feel free to correct me if im wrong but just seems like an easy addition that woul dhave no noticeable drawback only a benefit ?
You're a Legend!! Ace build, and thanks for putting that much info into your posts, it's good to hear it from someone who has a good idea about these things!! 
Paul.
325i sport Tech1
335i Chromie - Sold
2001 E46 M3-Sold
1999 E39 M5
325i sport Tech1
335i Chromie - Sold
2001 E46 M3-Sold
1999 E39 M5
This is an absoloutly fantastic write up. Should be made a sticky IMO
E30 340i project in progress now 328 turbo
Breaking '97 728i Auto box, tubular manifolds and other morsels.
For sale E34 M50 sump, pick up and dip stick. PM for de
Breaking '97 728i Auto box, tubular manifolds and other morsels.
For sale E34 M50 sump, pick up and dip stick. PM for de
I vote zone gold after tge thread has been tidy up and the car is finshed. Just as a step by step rebuild. That would be a top read.
Last edited by Dezzy on Fri Nov 20, 2009 11:31 am, edited 1 time in total.
Co Founder of CR24vTM By Invitation Only. Absolutely no riff raff!!!
-
Dreamracer1
- E30 Zone Regular
- Posts: 609
- Joined: Sat Sep 06, 2008 11:00 pm
- Location: Crymych, Pembrokeshire
Here here.
And he hasn't even finished, hell, he has barely started!
And he hasn't even finished, hell, he has barely started!
E-mail kandkwalden@aol.com, phone 07854043093
Please buy some of the bits off this old 320i!
Please buy some of the bits off this old 320i!
-
jaistanley
- E30 Zone Addict
- Posts: 2517
- Joined: Tue Jan 18, 2005 11:00 pm
- Location: Coventry and Essex
I have a feeling when the S14 goes back in it'll be in 'reasonable' condition!!
I just vote that you take it to 2.5 and put some nice cams and a carbon airbox on it.. That said I much prefer S50'd E30's, but then I would say that.. lol
Good work, love to see threads like this - sick of 'do these plastic tat bits look good' threads!
Jai
I just vote that you take it to 2.5 and put some nice cams and a carbon airbox on it.. That said I much prefer S50'd E30's, but then I would say that.. lol
Good work, love to see threads like this - sick of 'do these plastic tat bits look good' threads!
Jai
-
Morat
- E30 Zone Team Member
- Posts: 8943
- Joined: Thu Feb 09, 2006 11:00 pm
- Location: The Peoples Republic of Yorkshire
God, imagine if he put BruvvaBrowzzz on it!jaistanley wrote:I have a feeling when the S14 goes back in it'll be in 'reasonable' condition!!
I just vote that you take it to 2.5 and put some nice cams and a carbon airbox on it.. That said I much prefer S50'd E30's, but then I would say that.. lol
Good work, love to see threads like this - sick of 'do these plastic tat bits look good' threads!
Jai
E30 Touring 0.35 cD - more slippery than prison soap 
Praise the Lard... and pass the dripping!
Praise the Lard... and pass the dripping!
Thanks again for the kind words folks,
I know the mechanical bits can be a bit boring,
but it's all gotta be done.
Gearbox is assunder at the moment and we're
right at that point where your waiting for the
replacement parts to arrive and thinking
"how the f*ck does this go back together".
DanThe
Your putting an S14 back in?
Yep, love that engine, the sound alone is a large
part of the reason why I first bought an M3. Bloody expensive
lump to buy parts for though
Messenjah
that little breather hole ... would it not be wise to run a
breather pipe from that to somewhere dry ?
That makes perfect sense, sticking it on the list of
things to do. Cheers.
e21Jason
Are you going to be publishing the E30 M3 Restoration Bible.
Nah, theres people out there that know a hell of a lot
more than me about doing this stuff, we'll let them write the
books. Besides, don't think I could sleep at night charging
people to read this waffle.
I know the mechanical bits can be a bit boring,
but it's all gotta be done.
Gearbox is assunder at the moment and we're
right at that point where your waiting for the
replacement parts to arrive and thinking
"how the f*ck does this go back together".
DanThe
Your putting an S14 back in?
Yep, love that engine, the sound alone is a large
part of the reason why I first bought an M3. Bloody expensive
lump to buy parts for though
Messenjah
that little breather hole ... would it not be wise to run a
breather pipe from that to somewhere dry ?
That makes perfect sense, sticking it on the list of
things to do. Cheers.
e21Jason
Are you going to be publishing the E30 M3 Restoration Bible.
Nah, theres people out there that know a hell of a lot
more than me about doing this stuff, we'll let them write the
books. Besides, don't think I could sleep at night charging
people to read this waffle.
-
Fushion_Julz
- E30 Zone Camper
- Posts: 1295
- Joined: Tue Jun 07, 2005 11:00 pm
- Location: Blackwater
Chap, I disagree...I have found your detailed photo and explanation thread on the body and paintwork prep highly useful and informative...x-works wrote: Nah, theres people out there that know a hell of a lot
more than me about doing this stuff, we'll let them write the
books. Besides, don't think I could sleep at night charging
people to read this waffle.
A book, or at least a sticky thread with pictures hosted in perpetuity, would be a worthwhile addition to the cumulative knowledge of the community...
1987 Henna Rot M3 (was 195bhp CAT..now more and no cat)
2001 E46 330i SE Touring (manual)
2001 E46 330i SE Touring (manual)
This is an absolutely epic thread, that is fantastic work you have put in and I'm amazed at your attention to detail. The finished product will be fantastic, but nothing can convey just what effort you've put in without reading about it like this!
-
fourmotion
- E30 Zone Regular
- Posts: 281
- Joined: Sun Jul 30, 2006 11:00 pm
Awesome thread dude! I admire (and envy!) you doing all the work yourself. I know that as much as id like to have a go and try to do it myself, it would more than likely end up a whole lot worse than i could ever imagine!
Keep up the strong work though fella, i bet those nights are long but the end result will be a phenomenal motor!
Cheers,
Warren
Keep up the strong work though fella, i bet those nights are long but the end result will be a phenomenal motor!
Cheers,
Warren
-
Royalratch
- E30 Zone Addict
- Posts: 4921
- Joined: Sat Oct 21, 2006 11:00 pm
- Location: London
Galactic thread. I thought I saw this finished on another forum but it's still rocking.
Your generosity with your knowledge and time in preparing such great posts are very much appreciated.
Your generosity with your knowledge and time in preparing such great posts are very much appreciated.
-
e30topless
- E30 Zone Team Member
- Posts: 13598
- Joined: Wed Aug 23, 2006 11:00 pm
- Location: surrounded by scrap
Superb thread and very interesting !
unbelievable amount of work gone in here, nothing but sheer dedication on a grand scale
how many hours have gone into this already? (not including photography )
I would hate to get the final bill when this is done ! amazing how the 'little things' stack up on a project like this ,
surely this will be one of the best M3's out there when done ?
unbelievable amount of work gone in here, nothing but sheer dedication on a grand scale
how many hours have gone into this already? (not including photography )
I would hate to get the final bill when this is done ! amazing how the 'little things' stack up on a project like this ,
surely this will be one of the best M3's out there when done ?
-
gooner1
- Out humping Reindeer
- Posts: 13280
- Joined: Fri Apr 14, 2006 11:00 pm
- Location: Northampton.For my sins.
X WORKS, even i,ve read this from start to finish. Enjoyed it all, and even understood some of it. You have a very readable and entertaining writing skill. Am in complete awe of the work carried out, and to all those questioning the engine choice, do your own bleeding resto. Thank you. 
-
madaboutthe30
- E30 Zone Camper
- Posts: 1392
- Joined: Sun Oct 21, 2007 11:00 pm
- Location: Stanmore, Harrow
the guy's a lengend! Wise idea in sticking the s14 back in
Dreaming of the day I purchase an E30 M3
--- e30 motorsport cab-- in the process of becoming a trailer queen
--- Z4M Coupe - daily driver
--- e30 motorsport cab-- in the process of becoming a trailer queen
--- Z4M Coupe - daily driver
-
Royalratch
- E30 Zone Addict
- Posts: 4921
- Joined: Sat Oct 21, 2006 11:00 pm
- Location: London
What's the latest!
Just finished rebuilding the gearbox yesterday
and had no bits left over which is a welcome change.
Will try and get the pic's and waffle up by next weekend.
and had no bits left over which is a welcome change.
Will try and get the pic's and waffle up by next weekend.
-
E30BeemerLad
- Married to the E30 Zone
- Posts: 16806
- Joined: Mon Mar 28, 2005 11:00 pm
- Location: Norfolk
Can't believe I had not read this thead until now.
Absoluely first class work, I don't think there are words to express how stunning your finish is.
I'd like to also thank you for taking the time to share in detail your exploits as I'm sure plenty of us are learning a lot from it.
Absoluely first class work, I don't think there are words to express how stunning your finish is.
I'd like to also thank you for taking the time to share in detail your exploits as I'm sure plenty of us are learning a lot from it.
-
Royalratch
- E30 Zone Addict
- Posts: 4921
- Joined: Sat Oct 21, 2006 11:00 pm
- Location: London
That said, what's the latest!
gearbox write up is taking forever, worried interweb
might collapse under the weight of bullsh*t when this
gets uploaded. Might be up tomorrow eve.
Firefox spellchecker is asking if I want to
change to "dyslexic mode".
might collapse under the weight of bullsh*t when this
gets uploaded. Might be up tomorrow eve.
Firefox spellchecker is asking if I want to
change to "dyslexic mode".
Evenin all,
Bit of a gap since the last update, was so busy working on the car
I couldn't get time to write up all the work. Managed to get a lot
done since the last update.
And when you run that through the "Babelfish Bullsh*t Translator" it comes out
as:
Ages since the last update cause the shed feels like the inside of a freezer
at this time of year and everything you pick up brings frostbite a step closer.
The heater heats itself and nothing else and the camera took on a life of its own
and decided to mix up all the photos for the crack.
So heres what actually got done.
The driveshaft....
despite looking their age both joints on the shaft still rotate in all directions
without any sticking or tightness, so a clean up and they're good to go.....
what is getting changed is the centre bearing. Before splitting the shaft
a quick check for the original marks to help align it correctly when going
back together. If they're gone, two small dabs of tipex will do.....
collar screwed back off the shaft and splines slid apart.....
a slice around the rubber allows the outer piece of carrier bearing
to be cut away (along with tops of fingers).....
pop the circlip and the large washer behind it off....
and then simply pull the bearing off the shaft with the pullers....
which is how it goes in the fantasy world of "workshop manual land".
However in the real world no amount of pulling, beating or swearing
would remove the bearing. So the special bearing removing tool had
to be used, also known as an angle grinder.....
shaft gets a quick lick of sandpaper to clean up where the new
bearing is going to sit....
the new carrier bearing has the bearing recessed on one side like so......
and flush on the other side like so.....
the bearing in the centre is heated up using the heat gun....
which allows it to slide up on to the shaft easily, with the recessed
side facing in and the flush side facing out like so.....
then the washer and circlip go back on and if you've fitted the
bearing the wrong way around you now realise the cirlip won't
reach in to fit in it's groove anymore, which will mean the whole thing has
to come off again to be flipped around, which is nice......
then the threaded cup is slid back up on to the splines, some copper
grease on the splines and then the other half of the shaft is slid back
on with the white marks aligned....
The threaded cup isn't tightened up to lock the shaft length till it's
all refitted back on the car and extended to the correct length....
The last thing to do then was rebolt the rubber "guibo"
or donut onto the gearbox end of the shaft. Mine was in
good nick as i'd only replaced it a while back. Unfortunately
shortly after replacing it I read about the E34 M5 one
(p/n 26 11 2 226 527) being a straight forward replacement,
only its alot thicker and as such most probably longer lasting,
(f*ck it anyway)......
Bit of a gap since the last update, was so busy working on the car
I couldn't get time to write up all the work. Managed to get a lot
done since the last update.
And when you run that through the "Babelfish Bullsh*t Translator" it comes out
as:
Ages since the last update cause the shed feels like the inside of a freezer
at this time of year and everything you pick up brings frostbite a step closer.
The heater heats itself and nothing else and the camera took on a life of its own
and decided to mix up all the photos for the crack.
So heres what actually got done.
The driveshaft....
despite looking their age both joints on the shaft still rotate in all directions
without any sticking or tightness, so a clean up and they're good to go.....
what is getting changed is the centre bearing. Before splitting the shaft
a quick check for the original marks to help align it correctly when going
back together. If they're gone, two small dabs of tipex will do.....
collar screwed back off the shaft and splines slid apart.....
a slice around the rubber allows the outer piece of carrier bearing
to be cut away (along with tops of fingers).....
pop the circlip and the large washer behind it off....
and then simply pull the bearing off the shaft with the pullers....
which is how it goes in the fantasy world of "workshop manual land".
However in the real world no amount of pulling, beating or swearing
would remove the bearing. So the special bearing removing tool had
to be used, also known as an angle grinder.....
shaft gets a quick lick of sandpaper to clean up where the new
bearing is going to sit....
the new carrier bearing has the bearing recessed on one side like so......
and flush on the other side like so.....
the bearing in the centre is heated up using the heat gun....
which allows it to slide up on to the shaft easily, with the recessed
side facing in and the flush side facing out like so.....
then the washer and circlip go back on and if you've fitted the
bearing the wrong way around you now realise the cirlip won't
reach in to fit in it's groove anymore, which will mean the whole thing has
to come off again to be flipped around, which is nice......
then the threaded cup is slid back up on to the splines, some copper
grease on the splines and then the other half of the shaft is slid back
on with the white marks aligned....
The threaded cup isn't tightened up to lock the shaft length till it's
all refitted back on the car and extended to the correct length....
The last thing to do then was rebolt the rubber "guibo"
or donut onto the gearbox end of the shaft. Mine was in
good nick as i'd only replaced it a while back. Unfortunately
shortly after replacing it I read about the E34 M5 one
(p/n 26 11 2 226 527) being a straight forward replacement,
only its alot thicker and as such most probably longer lasting,
(f*ck it anyway)......
Last edited by x-works on Wed Dec 30, 2009 5:15 pm, edited 1 time in total.
With the driveshaft out of the way, there was no avoiding it any longer,
next up was going to be the big aluminium box full of gears.
First thing to note is, the following waffle is all about the Getrag 265/5
dogleg gearbox. The bit thats worth noting about that, is, the 265/5
gearbox is the dog leg gearbox, meaning that 1st is all
the way over to the left and down (under reverse).
The Getrag 265/6 which was also fitted to M3's (mostly
American versions I think) is the non dog leg 5 speed overdrive gearbox.
It pays to make a mental note of the difference between a 265/5 and
a 265/6 cause when your looking up parts on real.oem or looking up
the manual for torques or proceedures theres a difference between
the two internally. And its frustrating ordering in parts for your
box only to find upon collection that the bits you've ordered are
for the wrong one and are non refundable. (And despite trying,
no amount of hammering will make them fit)
On to the actual disassembly of the box. This is
a very complicated proceedure, and I'm now going to attempt to
explain the highly skilled, meticulous, disassembly of my gearbox.
Measure in exactly 253 mm from the rear output flange and
up 176mm from the bottom of the casing on the left hand side and
mark this spot with a large red x.....
Then hit this spot an unmercyfull wallop with special tool part
no. 959sledgehammer.....
and ta-daaaa......
(click on the picture for full size image)
For anyone who's not comfortable using the sledge hammer method of disassembly,
the the full strip down procedure is given here in the Bmw workshop manual....
http://www.bmwtechinfo.com/repair/main/421en/index.htm
click the link, click on the "contents" box, click on "23 manual transmission"
and then make sure you click on the right gearbox 265/5 or 265/6.
With the gearbox assunder it can help a little to know how all this crap in
here is supposed to work. If for no other resason just so you can easily
identify what part of the rebuild has gone t*ts up.
WARNING: You will most likely know less about the workings
of a gearbox after reading my explanation than before reading it.
Inside the gearbox casing theres 3 main shafts.....
Theres one or two cogs missing from the above picture but its enough to
get the idea. Pictured are the 3 shafts, the input, output and layshaft. The first
thing thats makes f*ck all sense, at first, is how is the top shaft in the picture is
in fact two shafts (input shaft & output shaft)?
The input shaft as seen below is short and only has one gear
and one bearing on it, and in the end of the input shaft is
a hole with a small roller bearing in it which allows the other
shaft, the output shaft, to sit into it and be supported......
new bearing in the hole, old one out on the bench....
The whole idea behind this setup is that the two shafts can move at
different speeds to each other. The input shaft at the front of the box
is connected through your clutch to the engine flywheel. So, with
the clutch let out this shaft is always spinning at engine speed. The whole aim
of the game is to pass this drive through a series of gears to reduce the revs
coming out the back of the box. 1st gear reducing it the most, working
right up to 5th gear which in this box is 1:1 ie one turn in = one turn out.
And heres the selection of gears it uses to do this......
(1st and reverse are missing from right of pic)
With the input shaft spinning the one gear thats solidly connected
to this (5th gear) is also spinning....
and because 5th gear on the input shaft is also connected to
5th gear on the layshaft (underneath it) then the whole layshaft
is also spinning too. And because basically the layshaft is one
big solid lump of metal, then all the other gears it's in contact with
are spinning too.
So, gearbox in neutral, engine turning over, all thats marked
red is spinning at engine speed....
So how the fu*k is the output shaft coming out the back of the box
not spinning if all the gears on it are spinning?......
The answer is all the gears on the output shaft (top shaft), while sitting on it, are
not actually connected to it. Between the centre of the gears and
and the shaft are little roller bearings, so no matter how fast you
turn the gears you wont turn the shaft.....
So to get the output shaft to turn you have to "lock" one of these
gears to the shaft and to do this you use the syncro hubs.....
The syncro hubs sit in between the gears and have two main pieces.
The centre of the syncro hub is connected solidly to the output
shaft by splines (red bit in pic below) and the outside part (blue bit)
is also splined onto the red bit, the only difference being the
blue piece can slide over and back on the red piece.....
The reason it can slide over and back is so it can lock on to these little
teeth on the side's of the main gears (red piece below) while also staying
connected to the centre of the syncro hub.........
So when the blue piece of the syncro hub slides over to grab these
red teeth in the pic below it's also still connected to the centre piece
of the syncro hub, and bingo, you've just locked one of the gears
to the output shaft. Now the output shaft is being driven......
In the pic below the red syncro hub is slid to the
left and the gear to the left of it (3rd gear) is "engaged" and locked to the
output shaft, hence the output shaft (To Differential) is now
been driven by the engine.....
The other bit in here thats important is the syncro ring.....
It sits in between the gear and the syncrohub and it has the shittiest job
of the lot. When the syncro hub moves over to grab them little teeth
on the side of the gear and lock it on to the shaft it runs into a little
problem. The hub and the gear are rotating at different speeds. So
if one tries to mesh with the other like this then theres going to be
a horrible sound in the gearbox and a whole lot of new little bits
stuck to that drain bung magnet. What needs to happen is the two
need to be rotating at the same speed so they can lock together.
This is where the syncro ring comes in. The inside of the syncro ring
is cone shaped.....
and the bit of the gear it slides on to is also cone shaped.....
so as the syncro hub sleeve moves across it grabs the brass syncro
ring first and then squeezes this up against the gear to get it rotating at
the same speed and then as they synchronize it can then slide fully across
and lock onto the gear......
And then at last, the final bit, for anyone left that hasn't got bored and
logged out to go look for porn sites. How does moving one simple
gear lever from up in the drivers seat move all these syncro hubs
down in the gearbox?
The box has 6 gears, 1st 2nd 3rd 4th 5th and reverse that can be selected.
Each syncro hub can slide forward or back to select the gear in front
of it or behind it, so thats 3 syncro hubs that need to moved.
A brass "selector fork" sits on to each one of these syncro hubs....
and these 3 selector forks are solidly connected to 3 rods....
(only 2 forks in picture)
Theres also another rod in there too, its the "selector rod" and its
the only one thats connected to your gearlever. When you move your
gearlever right it rotates right, move your gearlever left it rotates left.....
attached to this "selector rod" (the funky green one) is a finger (also
funky green). And as mentioned when you move the gearlever left
and right when in neutral the green rod rotates left and right moving
this green finger up and down between the 3 selector fork rods
(funky purple, blue and yellow).........
move the gearlever all the way to the right, the selector rod
rotates all the way to the right and the finger moves all the way up
to engauge with a cut out in the purple rod. Now when you move
the gear lever back or forward in to 4th or 5th gear position the
green finger moves the purple rod backwards or forwards, which
in turn moves the purple fork which moves the syncro hub forward
to engage 5th gear or backwards to engauge 4th.....
Leave the gear lever in the middle position and move it backwards
or forwards between 2nd and 3rd gear position and the green finger
hooks up with the blue shaft and fork moving the 2nd/3rd syncro hub
locking in either 2nd or 3rd gear.....
and finally move the lever all the way to the left over for reverse
and first, the green finger gets rotated all the way down to hook up
with the yellow shaft and either select 1st or reverse down the back
of the box......
And thats roughly how it all works,
I think,
maybe.
next up was going to be the big aluminium box full of gears.
First thing to note is, the following waffle is all about the Getrag 265/5
dogleg gearbox. The bit thats worth noting about that, is, the 265/5
gearbox is the dog leg gearbox, meaning that 1st is all
the way over to the left and down (under reverse).
The Getrag 265/6 which was also fitted to M3's (mostly
American versions I think) is the non dog leg 5 speed overdrive gearbox.
It pays to make a mental note of the difference between a 265/5 and
a 265/6 cause when your looking up parts on real.oem or looking up
the manual for torques or proceedures theres a difference between
the two internally. And its frustrating ordering in parts for your
box only to find upon collection that the bits you've ordered are
for the wrong one and are non refundable. (And despite trying,
no amount of hammering will make them fit)
On to the actual disassembly of the box. This is
a very complicated proceedure, and I'm now going to attempt to
explain the highly skilled, meticulous, disassembly of my gearbox.
Measure in exactly 253 mm from the rear output flange and
up 176mm from the bottom of the casing on the left hand side and
mark this spot with a large red x.....
Then hit this spot an unmercyfull wallop with special tool part
no. 959sledgehammer.....
and ta-daaaa......
(click on the picture for full size image)
For anyone who's not comfortable using the sledge hammer method of disassembly,
the the full strip down procedure is given here in the Bmw workshop manual....
http://www.bmwtechinfo.com/repair/main/421en/index.htm
click the link, click on the "contents" box, click on "23 manual transmission"
and then make sure you click on the right gearbox 265/5 or 265/6.
With the gearbox assunder it can help a little to know how all this crap in
here is supposed to work. If for no other resason just so you can easily
identify what part of the rebuild has gone t*ts up.
WARNING: You will most likely know less about the workings
of a gearbox after reading my explanation than before reading it.
Inside the gearbox casing theres 3 main shafts.....
Theres one or two cogs missing from the above picture but its enough to
get the idea. Pictured are the 3 shafts, the input, output and layshaft. The first
thing thats makes f*ck all sense, at first, is how is the top shaft in the picture is
in fact two shafts (input shaft & output shaft)?
The input shaft as seen below is short and only has one gear
and one bearing on it, and in the end of the input shaft is
a hole with a small roller bearing in it which allows the other
shaft, the output shaft, to sit into it and be supported......
new bearing in the hole, old one out on the bench....
The whole idea behind this setup is that the two shafts can move at
different speeds to each other. The input shaft at the front of the box
is connected through your clutch to the engine flywheel. So, with
the clutch let out this shaft is always spinning at engine speed. The whole aim
of the game is to pass this drive through a series of gears to reduce the revs
coming out the back of the box. 1st gear reducing it the most, working
right up to 5th gear which in this box is 1:1 ie one turn in = one turn out.
And heres the selection of gears it uses to do this......
(1st and reverse are missing from right of pic)
With the input shaft spinning the one gear thats solidly connected
to this (5th gear) is also spinning....
and because 5th gear on the input shaft is also connected to
5th gear on the layshaft (underneath it) then the whole layshaft
is also spinning too. And because basically the layshaft is one
big solid lump of metal, then all the other gears it's in contact with
are spinning too.
So, gearbox in neutral, engine turning over, all thats marked
red is spinning at engine speed....
So how the fu*k is the output shaft coming out the back of the box
not spinning if all the gears on it are spinning?......
The answer is all the gears on the output shaft (top shaft), while sitting on it, are
not actually connected to it. Between the centre of the gears and
and the shaft are little roller bearings, so no matter how fast you
turn the gears you wont turn the shaft.....
So to get the output shaft to turn you have to "lock" one of these
gears to the shaft and to do this you use the syncro hubs.....
The syncro hubs sit in between the gears and have two main pieces.
The centre of the syncro hub is connected solidly to the output
shaft by splines (red bit in pic below) and the outside part (blue bit)
is also splined onto the red bit, the only difference being the
blue piece can slide over and back on the red piece.....
The reason it can slide over and back is so it can lock on to these little
teeth on the side's of the main gears (red piece below) while also staying
connected to the centre of the syncro hub.........
So when the blue piece of the syncro hub slides over to grab these
red teeth in the pic below it's also still connected to the centre piece
of the syncro hub, and bingo, you've just locked one of the gears
to the output shaft. Now the output shaft is being driven......
In the pic below the red syncro hub is slid to the
left and the gear to the left of it (3rd gear) is "engaged" and locked to the
output shaft, hence the output shaft (To Differential) is now
been driven by the engine.....
The other bit in here thats important is the syncro ring.....
It sits in between the gear and the syncrohub and it has the shittiest job
of the lot. When the syncro hub moves over to grab them little teeth
on the side of the gear and lock it on to the shaft it runs into a little
problem. The hub and the gear are rotating at different speeds. So
if one tries to mesh with the other like this then theres going to be
a horrible sound in the gearbox and a whole lot of new little bits
stuck to that drain bung magnet. What needs to happen is the two
need to be rotating at the same speed so they can lock together.
This is where the syncro ring comes in. The inside of the syncro ring
is cone shaped.....
and the bit of the gear it slides on to is also cone shaped.....
so as the syncro hub sleeve moves across it grabs the brass syncro
ring first and then squeezes this up against the gear to get it rotating at
the same speed and then as they synchronize it can then slide fully across
and lock onto the gear......
And then at last, the final bit, for anyone left that hasn't got bored and
logged out to go look for porn sites. How does moving one simple
gear lever from up in the drivers seat move all these syncro hubs
down in the gearbox?
The box has 6 gears, 1st 2nd 3rd 4th 5th and reverse that can be selected.
Each syncro hub can slide forward or back to select the gear in front
of it or behind it, so thats 3 syncro hubs that need to moved.
A brass "selector fork" sits on to each one of these syncro hubs....
and these 3 selector forks are solidly connected to 3 rods....
(only 2 forks in picture)
Theres also another rod in there too, its the "selector rod" and its
the only one thats connected to your gearlever. When you move your
gearlever right it rotates right, move your gearlever left it rotates left.....
attached to this "selector rod" (the funky green one) is a finger (also
funky green). And as mentioned when you move the gearlever left
and right when in neutral the green rod rotates left and right moving
this green finger up and down between the 3 selector fork rods
(funky purple, blue and yellow).........
move the gearlever all the way to the right, the selector rod
rotates all the way to the right and the finger moves all the way up
to engauge with a cut out in the purple rod. Now when you move
the gear lever back or forward in to 4th or 5th gear position the
green finger moves the purple rod backwards or forwards, which
in turn moves the purple fork which moves the syncro hub forward
to engage 5th gear or backwards to engauge 4th.....
Leave the gear lever in the middle position and move it backwards
or forwards between 2nd and 3rd gear position and the green finger
hooks up with the blue shaft and fork moving the 2nd/3rd syncro hub
locking in either 2nd or 3rd gear.....
and finally move the lever all the way to the left over for reverse
and first, the green finger gets rotated all the way down to hook up
with the yellow shaft and either select 1st or reverse down the back
of the box......
And thats roughly how it all works,
I think,
maybe.
Last edited by x-works on Sat Jan 02, 2010 12:57 am, edited 4 times in total.
-
Royalratch
- E30 Zone Addict
- Posts: 4921
- Joined: Sat Oct 21, 2006 11:00 pm
- Location: London
L:chuckle:L!
Awesome! Dismantle the engine already!
Awesome! Dismantle the engine already!