possible hydraulically lockable (EH) diff conversion?

[gareth]

i recently bought a wierd medium case EH diff from ebay. it's for a E34 525ix (4x4 thingy) and had a 3.38:1 ratio which i intended to rob.

since pulling the thing apart, i've found it's rather cool!
there is a hydraulic line that attaches to a hydralic cylinder on the n/s input flange. this pushes on some meaty thrust bearings and locks up a 7 plate clutch!

anyone had a play with one of these things? i'm trying to gather info as i'm tempted to try and fit it to my 335i

comparison between a E30 large case diff and the EH one:



the LSD pack:


the hydraulic cylinder:


the 7 plate clutch


more pics:
http://smg.photobucket.com/albums/v382/ ... EH%20diff/

the control gubbins
http://www.realoem.com/bmw/showparts.do ... g=33&fg=20


does anyone know much about these?

[Toby_Unna]

does anyone know much about these?

i know they look very cool when taken to bits

sorry Gareth as usual i can be of little help

[chu346]

If you put a hydraulic feed to it surely it would lock up?

So surely you could have a second handbrake lever that is hydraulic and lock the diff whenever you want.

[gareth]

does anyone know much about these?

i know they look very cool when taken to bits

sorry Gareth as usual i can be of little help

no worries, amusing all the same!

[gareth]

If you put a hydraulic feed to it surely it would lock up?

So surely you could have a second handbrake lever that is hydraulic and lock the diff whenever you want.

yup!

the piston area on the diff looks very large so a hydraulic handbrake lever would probably have too small a piston resulting in huge travel.

i've heard that the fateful vauxhall 4x4 (cav / calibra turbo) system uses electronic control to regulate the hydraulic pressure from the pas pump to the chocolate transfer box. maybe the valve setup from this could be adapted? there are a lot of breakers out there! then i could rig up a diff lock button

[Toby_Unna]

chocolate transfer box

[Laimis]

I have same diff from 525ix laying in my garage. Sometimes i'm thinking about using it in e30, oil pressure thing probably is doable, but differential control is another story, i doubt that manual locking/unlocking is comfortable.. And racing differential computers are very expensive and complex.

[gareth]

cool, do you have ano of the other bits that went with it?

all i would want is an open diff til i lock it solid!

[Laimis]

cool, do you have ano of the other bits that went with it?

Probably no, i was breaking this car one year ago and after garage cleaning many small stuff is gone now

[gareth]

oh well. for the time being, i'm probably just going to rob the crownwheel and pinion from it and build up a 3.38:1 E30 LSD.

maybe revisit this in the future. i suspect this would be just the tool for someone drag racing or drifting but for road use, it's probably a bit silly unless computer controlled... sod that!

[320Touring]

oh well. for the time being, i'm probably just going to rob the crownwheel and pinion from it and build up a 3.38:1 E30 LSD.

maybe revisit this in the future. i suspect this would be just the tool for someone drag racing or drifting but for road use, it's probably a bit silly unless computer controlled... sod that!

surely you could rig up some pipework to give you like 3 manual locking stages..

say 25% (on road LSD)

50% (drag and track use)

100% driffty migspec

[gareth]

possible but it would need some form of exhausting pressure valve connected to the PAS system. not easy and i'd rather spend the time / money on other stuff now i think about it!

a nice idea though

[m-dtech]

multistage valve similar idea to jcb ??

off position closes the feed to the diff from PAS system and pipes return back into resevoir. ??

the valve i have to control my loader on massey ferguson is what you want.

i can slowly raise or lower the arms by opening/closing valve, when i move to off the arms drop and preasure is released from the system and returned to resevoir.