Hello e31 friends! I'm converting my '89 750iL to a manual trans and am looking for 850ci or csi clutch kit options. I've amassed all of the other necessary bits, and thought this would be the easy part, but thus far I've come up nearly empty :'( Looks like the OEM parts are NLA as of 2010, and many of the aftermarket options have been discontinued.
I'm using an oem 850 manual single mass flywheel and a Getrag 420g with and adapter ring (will accommodate the 280mm clutch no problem). This particular 420g (from an e34 540i) has a 1-3/8", 10 spline input shaft just like the 560g used in the e31, so any stock 850 (ci or csi) clutch, bearing, and pressure plate should work.
I purchased an Exedy kit that claimed 850csi fitment on eBay, and it's all wrong (huge surprise, right?), so I'm hoping someone might be able to tell me what they've had success with before I just guess again. I know manual e31s are somewhat rare, but surely someone here has replaced a clutch in the last five years? Here are the options I've found to date that I *think* will work:
- Spec SB271
- Seems like possibly the best option. About 50% more than I'd hoped to spend, but I've come this far...
- http://www.specclutches.com/68758
- $800 + an oem throwout
- Exedy KBM10
- NLA from Exedy. Few sellers on eBay charging big money. Specs look right, but is there a better option?
- I now know from personal experience that the KBM11 some sellers list for the 850 _does not_ fit
- $1,300 for the kit
- Centerforce II MST559033
- Another one that someone has listed for the 850 that I can find nothing to substantiate fitment. The disc, at least, looks like it would work. The overall diameter and input shaft dimensions are right. No idea about the pressure plate though. The manufacturer's documentation only lists Ford applications.
- https://www.summitracing.com/parts/c...9033/overview/
- $270 + an oem throwout, which seems too good to be true!
- UUC Moter Werks
- I list these guys only because they technically offer an option, but at a price point higher than I have invested in the whole project to date, so I'm not seriously considering them.
- http://store.uucmotorwerks.com/clutc...anic-p457.aspx
- $1650
- BMW OEM NOS parts I've crossed numbers and found online. In stock? Who knows. Seems risky...
- 21211223408 - Reman pressure plate - $200
- 21211223410 - Reman clutch disk - $240
Any luck with any of the above? Other ideas? If this has been discussed elsewhere, I apologize. I've searched this (and several other) and found a lot of folks discussing this swap, but precious few details about anyone completing it and no good clutch info. I should probably take that as a sign, but what fun would that be? Thanks!
Last edited by sutekh; 05-20-2018 at 05:35 PM.
I'm in the process of replacing my clutch. I purchased the UUC kit with the 850csi conversion kit. I will keep you posted on how it goes. Should be completed by June 4th. I'm dropping car off to Indy before I go out of town for 2 weeks. Clutch kit is for my e31, therefore I spared no expense.
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'91 Dinan 860 Stage III (new 6L engine)
'91 Dinan 850 TT stage III (brand new engine) 21st Century Tech meets 18th Century Dinan...
'91 850i 6sp (mint) (sold)
'90 Dinan 750iL TT stage III (Guido - The Beast)
'94 850 CSi The Detroit Auto Show car (restored to factory perfect) (sold)
'96 850Ci, The George Carlin car
''73 3.0 csi, '08 535i, '03 X5 4.6is
...and a few other non BMW cars
Thanks for the suggestions! As I understand it, the SB011 referenced there is the 850CSI version of the SB271 I mentioned as my likely best option. The SB011 seems to run ~$50 cheaper everywhere, but since I have an M70, not an S70, I figure the SB271 is the better bet (although the SMF p/n is the same, so I suspect either would work).
Since posting, I did identify an updated p/n for the remanufactured BMW kit: 21210444900. Best price I've found is $940, but it appears to include the throw-out, so that certainly makes it competitive with the SPEC option. Probably what I'll end up purchasing.
If you plan to do anything greater than stock power, look for an aftermarket / non-OEM solution that can handle it. I have the CSi setup on a twin-turbo M70 car, and I have to baby that clutch. At stock power levels I'm sure it is fine, but I wish I had gone with something a little more heavy-duty at the time of the build. I certainly will if I ever run enough miles to need a replacement.
Cheers, John
The CSi kit is compatible with M70 too... same thing really. But lots of places don't actually recognize there were 6sp M70 cars and don't list anything, but do for the CSi's as they were all manual trans cars.
The link I posted for the Spec kit was markedly lower than from Spec itself...
'91 Dinan 860 Stage III (new 6L engine)
'91 Dinan 850 TT stage III (brand new engine) 21st Century Tech meets 18th Century Dinan...
'91 850i 6sp (mint) (sold)
'90 Dinan 750iL TT stage III (Guido - The Beast)
'94 850 CSi The Detroit Auto Show car (restored to factory perfect) (sold)
'96 850Ci, The George Carlin car
''73 3.0 csi, '08 535i, '03 X5 4.6is
...and a few other non BMW cars
Thanks for confirming what I suspected. I was ballparking the pricing based on MSRP, but this is the SB271 I have my eye on for $745: https://www.amazon.com/Spec-Tools-SB.../dp/B06XYTKDSH
Thanks for the power reminder, John. The 750 is currently parked next to my M30 powered e34 that I turbocharged several years ago, so forced aspiration is definitely a possibilityI'd hate to paint myself into a corner! I've definitely toyed with the notion of supercharging the M70 (which seems the most civilized option for that buttery smooth motor).
sutekh,
What clutch setup did you end up going with? Have you converted the 750il yet? I'm dreaming of converting my E32 750il to a 6 speed as well. Do you know if the 420g from the early E39 540i's has the same input spline as the 560g? I noticed you are using a 420g from an E34 540i, but I have always heard that the early E39 and E34 420g's are the same?
Also, with an adapter ring don't you need something to space the flywheel back from the crank? Thanks
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