Which gear linkage m50

[booomer]

Hi, just trying to find out which gear linkage to use as im putting the engine and gearbox out of an e34 525is into my e30 (previously a 316i). I've heard of people using all sorts of different ones but i'd like to know which is easiest in this case with minimal hassle if anyone has any suggestions

cheers

[Y_Cymro]

If you want the easiest route, wouldn't it be simpler to use your 316 gearbox? Presumably the existing mount, linkage, and prop could all be used? Either way you'd need to change the diff.

[booomer]

But wouldn't i then need a new clutch, flywheel and starter motor?

[blue30]

I used a 318 box, it went straight onto the M50 clutch no problemos. M50 starter to match the flywheel and my original 320i gear change linkage put the gear stick in the right place.

[booomer]

i could do one of these options but i already have a good working gearbox from the e34 so its gona be far cheaper to just wack a different linkage on it

[Bob_S]

with the e34 gearbox you're into unchartered territory as far as I am aware.

Most people tend to use the M4X gearboxes which are 10 a penny and I know for a fact an m42b18 gearbox will hold onto well over 200bhp and 200lb ft no problem. This means you simply use the 320i gear linkage like said above using a 325i prop shaft.

Other ways include the m20 gearbox which needs a custom linkage as it sits on an angle iirc

or the e36 M50/M52 gearbox's with a M3 or custom prop shaft

[E30BeemerLad]

I too am not sure what the deal is with the E34 gearboxes that are bolted to the M50. Could well be the same as the E36 M50 boxes though.

Using the donor car box is just hassle due to the E30 diff ratios being no good and also the horrible dual mass flywheel they have.

For a simple bolt-together solution (which is what I have used)

24v engine, E30 318iS gearbox, E30 325 flywheel, clutch & starter motor, E30 325 propshaft, E30 320i gear selector rod & cradle. No modifications needed to anything and all cheaply available

I paid £20 for flywheel, clutch & starter
Prop was £20 (came as part of a complete 325 rear end)
brand new 320 gear selector rod from the dealers was £20 The alloy cradle part was about £10 from Chris Warburton

[Guest]

with the e34 gearbox you're into unchartered territory as far as I am aware.

Most people tend to use the M4X gearboxes which are 10 a penny and I know for a fact an m42b18 gearbox will hold onto well over 200bhp and 200lb ft no problem. This means you simply use the 320i gear linkage like said above using a 325i prop shaft.

Other ways include the m20 gearbox which needs a custom linkage as it sits on an angle iirc

or the e36 M50/M52 gearbox's with a M3 or custom prop shaft

The E34 box is the same as the E36 M50/M52/M3 gearbox, so there is no problem with it.
Stick your E34 box in with a Z3 1.9 linkage from BMW parts department and you'll have a nice short throw gearchange.

[booomer]

Many thanks plumb, i new it wasnt impossible. Do you have first hand experience of using these components in a conversion? and do you know which prop shaft i will need?
cheers

[E30BeemerLad]

what diff are you using?

[booomer]

I'll be using the internals of the e34 LSD obviously re-cased into an e30 medium casing

[Bob_S]

You may know better than I but having a quick look on the ETK the e36 M3 and a e34 525 don't share the same part numbers for the gearboxes. I'm pretty sure the e36 328/M3 5 sp box is only found on these cars.

Also when you say a Z3 1.9 shifter are you on about the linkage to the gearbox or just the shift lever? I believe the OP was after information on what linkage to use as opposed to shift lever

booomer - e34's can be supplied with a large case diff I assume you have checked that the diff on your car is a medium cased diff?

[booomer]

Again going on information i have read on the zone, i am of the understanding that all e34 diff cases were large and that i will have to have mine re-cased into an e30 medium casing.

And yes i'm trying to find out what exactly will be bolted to the gearbox in terms of the prop and the gear linkage. At this moment in time i'm not bothered about short shifts. i just need the easiest and cheapest way of getting a driveable car

cheers

[booomer]

Also how do i get access to the/an ETK??

[Bob_S]

There are 3 diff sizes, small, medium and large. The e30 only used small and medium where the e34 used the medium and large sizes. You can't swop the internals unless it's like for like obviously.

The quickest way is to find the parts that are well documented. Where are you located? I'm sure an M4x box and 325 prop wont be hard to find.

www.realoem.com/bmw is the ETK, but the part no. cross referancing is a little dubious

[booomer]

If thats the case Re. the e34 diffs then i've been given incorrect information from other people as they have said that all e34 difs are in a large case but the internals will fit into an e30 medium case!?!?

Does anyone know if all e30 prop centre bearings are the same or will my 316i bearing be no good?

[DanThe]

The physical size of the case has nothing to do with how compatible the internals are, as Bob said, there are 3 sizes of diff, to be more specific, there are 3 sizes of diff 'crownwheels' 168mm 188mm and 210mm
Obviously different cars use different cases, the E34 medium 188 diffs (which are the same as a 'large E30' diff) are in big cases with totally different fixing points, hence why you need to rebuild them into an E30 case. The E34 210 diffs are not compatible with an E30 at all unless you chop up the rear beam and use custom drive shafts, you can not rebuild this diff into an E30 compatible case.

Prop centre bearings were changed sometime in 1986 or thereabouts

[booomer]

How then do i know which diff size i have?

[Guest]

How then do i know which diff size i have?

There is a 3 digit number on the casing or tag which identify the casing size, But I cant remember the numbers, IIRC 180ish is a small casing and a med is 200 and something.
Someone on here should be able to give you the correct numbers.

[ross_jsy]

24v engine, E30 318iS gearbox, E30 325 flywheel, clutch & starter motor, E30 325 propshaft, E30 320i gear selector rod & cradle. No modifications needed to anything and all cheaply available

is the 320 cradle/gear selector rod longer than a 325i part as my gear stick is about an inch too far forward in the hole

[E30BeemerLad]

the 320 stuff is a different length. Are you using the M40 or M42 gearbox?

[DanThe]

How then do i know which diff size i have?

There is a 3 digit number on the casing or tag which identify the casing size, But I cant remember the numbers, IIRC 180ish is a small casing and a med is 200 and something.
Someone on here should be able to give you the correct numbers.

The physical size of the case has nothing to do with how compatible the internals are, as Bob said, there are 3 sizes of diff, to be more specific, there are 3 sizes of diff 'crownwheels' 168mm 188mm and 210mm
Obviously different cars use different cases, the E34 medium 188 diffs (which are the same as a 'large E30' diff) are in big cases with totally different fixing points, hence why you need to rebuild them into an E30 case. The E34 210 diffs are not compatible with an E30 at all unless you chop up the rear beam and use custom drive shafts, you can not rebuild this diff into an E30 compatible case.

[DanThe]

If you are unsure post a picture of the diff and somebody will identify it

[ross_jsy]

the 320 stuff is a different length. Are you using the M40 or M42 gearbox?

using a 325i sport box

[bumhole]

I put the engine, box and slip diff out of a 525i sport same as you. I used the gear linkage off an e30 320i. It fits a treat. I used a 2.8 e36 prop. Rebuilding the diff was a tw#t but worth it. I sourced new bearings and front seal for it from a local bearing supplier, pulled the old ones off with a cheap flywheel puller, my mate made a tool to press the new ones on. oh, you will have to shave down the outside of a 24mm socket for the pinion nut, probably. I reckon this way saves a right load of messing with flywheels and gearboxes and ratios etc...
Oh yeah, Pinion nut torque I used was 135ft/lbs Took ages to find that out and apparently if you get it wrong your diff will be a whiner!

[booomer]

I put the engine, box and slip diff out of a 525i sport same as you. I used the gear linkage off an e30 320i. It fits a treat. I used a 2.8 e36 prop. Rebuilding the diff was a tw#t but worth it. I sourced new bearings and front seal for it from a local bearing supplier, pulled the old ones off with a cheap flywheel puller, my mate made a tool to press the new ones on. oh, you will have to shave down the outside of a 24mm socket for the pinion nut, probably. I reckon this way saves a right load of messing with flywheels and gearboxes and ratios etc...
Oh yeah, Pinion nut torque I used was 135ft/lbs Took ages to find that out and apparently if you get it wrong your diff will be a whiner!

Many thanks for that post, i knew it shouldnt be as hard as changing flywheels, clutches, starters etc.

[bumhole]

Is that the donor beast in your pic then? looks tidy! Mine was a right crapper!
Good luck with it!

[Y_Cymro]

I used a 318 box, it went straight onto the M50 clutch no problemos. M50 starter to match the flywheel and my original 320i gear change linkage put the gear stick in the right place.

Was it parts 1 and 11 you used?

[booomer]

Is that the donor beast in your pic then? looks tidy! Mine was a right crapper!
Good luck with it!

Na thats my daily driver (it'll be for sale soon) but the donor was very similar. I cant wait to get the e30 on the road and give it a good thrashing! Hopefully it will make all the hassles seem worth it!

[bumhole]

It will do I assure you! Another recommendation would be to send your injectors off to injectortune man on forum for a clean. I did and it was worth every penny. £67 posted

[booomer]

It will do I assure you! Another recommendation would be to send your injectors off to injectortune man on forum for a clean. I did and it was worth every penny. £67 posted

Sounds like a good idea, i'll look into that. On another note, can you remember which gearbox crossmember + rubber mounts you used?

[bumhole]

I'm pretty sure it was the e30's for both of them.
I just remembered that the gear linkage needed a spcacer on one bit of it that we made up with washers. It should become apparent.