what ratio do i have? pic included

[kevo]

hi all can anyone unravel the mystery?

[noney82]

were can i find my tag like that

[kevo]

if you look on the face of the diff under the car pointing out toward the rear it'll be on one of the bolts near the top under a pile of rust, if you can't see it it'll be removed/rusted away. did i mention rust ha ha
kev

[noney82]

yeah i keep finding bits if that poping up

[cliffybabe]

it look slike a slipper to me, ratio tbc

[kevo]

hiya cliffy, yeah i'm confident it's an LSD it turns right etc i'm just after the ratio so i can work out my gear ratios thinking of changing boxes round.

[noney82]

what would tag say if it was lsd

[SPADGE]

what would tag say if it was lsd

The 'S' signifies it as an LSD

[kevo]

it would have an s at the end of your ratio. normally you would have 3.91s or 3.67s etc which denotes the ratio and s for slipper. i'm only asking as mine says 0:11s confusing me somewhat.

if you're unsure jack the car up off the diff and turn the wheels if they both go the same way it's an lsd if they don't it ain't. you may have an lsd thats a bit poo too and needs rebuilding or at the very least refreshing the oil, if so use the best limited slip diff not diff but limited slip diff oil you can get castrol stuff is good from rally places, these oils pick up better and cause the plates to lock more efficiently than normal oil.

blah blah

cheers
Kev

[SPADGE]

it would have an s at the end of your ratio. normally you would have 3.91s or 3.67s etc which denotes the ratio and s for slipper. i'm only asking as mine says 0:11s confusing me somewhat.

if you're unsure jack the car up off the diff and turn the wheels if they both go the same way it's an lsd if they don't it ain't. you may have an lsd thats a bit poo too and needs rebuilding or at the very least refreshing the oil, if so use the best limited slip diff not diff but limited slip diff oil you can get castrol stuff is good from rally places, these oils pick up better and cause the plates to lock more efficiently than normal oil.

blah blah

cheers
Kev

S for slipper pmsl
The 'S' i suspect is for 'Sport'

[kevo]

ooohhh lah de dah it was only a guess mister. anyway we've all got slippers haven't we? mine have got scooby doo on them.

[SPADGE]

ooohhh lah de dah it was only a guess mister. anyway we've all got slippers haven't we? mine have got scooby doo on them.

I don't understand the first or last part of the above (Is it Welsh or Juvenile?) I was just trying to be helpful by giving you the correct meaning of the 'S' on your tag.

[noney82]

go on the scooby doo slippers lol, what do lsd's come as standard on

[StuBeeDoo]

Educated guess says that signifies it's a 40:11.
3.64 to you and me.
HTH
Stuart.

[mrLEE30]

that one is a mystery.... the factory tag would say S 3.64 1234 (last four are random!) which would mean ratio of 3.64 S = LSD and four digits which are production type code.

a replacement diff is different.. that would say 40 11 A 123 S which would mean 40 ring teeth driven by 11 pinion teeth (40/11=3.64) A for replacement diff 123 production code and S means LSD.

so that why this code does not seem to match. but for me i would say the 4 for the 40 11 has rusted away and the ratio is 3.64 (dont think there is a 5011 = 4.54 and sure there is no 3011 = 2.72) and the S seems to indicate it is a LSD.

the way to be sure is this...

mark a position on your wheel. turn the diff input shaft and count how many times it turns for one complete rotation of the wheel. if the input shaft turns 3.64 times and your wheel turns once there is your answer, if it turns 4.5 times then the rusted number is a 5!!

mrlee

[kevo]

nice one guys, the diff is off being rebuilt currently so i can't test it just yet but i'll assume it's a 3.64 for now as it came off a 325 1987 model which had lot's of optional extras. thanks for your help and i'll let you know if i find out for definite.

cheers
Kevo

[kevo]

how do noney82,
lsd's should come standard on all genuine 325i sport models (stressing the genuine bit ha ha), also they came on M3's. They were an option too but only on some cars from factory, i'm not entirely sure what cars didn't have them on the list but 318is/325 should have had them there waiting to be ticked; (318is had a small case lsd i believe). To be honest you can forget too much about what should and shouldn't have them nowadays because 90% of the e30's you'll find are 15yr oldish and if someones loved them in that long period of time they may well have gone and bought an lsd for it, the best way is to get out there and check your car.

kevo

lah de dah wasn't a juvenile dig, it was my embarrassed response for not knowing what 's' stood for. and surely we all have slippers anyway! you know the comfy things that keep your feet warm in the winter?? (hence the fact that mine have scooby doo on them)

[noney82]

cheers for that kevo, found me tag rusted up tho it fell off when i touched it so trying to sand rust down

[noney82]

3:73 9122 mine says from what i can make out

[kevo]

looks like you have a standard open type diff more than likely with a 3.73 ratio. just as a last resort did you try turning the wheels when they are in the air?

[noney82]

didnt jack car up i just squeezed under

[noney82]

i will try tho

[kevo]

unless you try squeezing under the car and bench pressing it up then spinning one of the wheels with your double jointed legs ha ha! if you can do that though you should be in a circus.

kevo

if your diff is open and you want to improve it put some 140weight gear oil in (transit stuff), it clings a bit better and improves it, it's never gonna be an lsd but it does make it a little more sticky worked well in my mx5 and ok in my e30 at the mo. it's cheap enough too btw bout a fiver or so.
kev

[noney82]

unless you try squeezing under the car and bench pressing it up then spinning one of the wheels with your double jointed legs ha ha! if you can do that though you should be in a circus.

im not that strong haha coud be handy if i was tho, i'll jack it up this week some time and look if not i'll save for a lsd and in meantime i'll put up with open diff but just take it easy as im sick of the back end going to far on me