Another clutch thread.

[CaffeinatedSoul]

Im new to understanding clutches as Ive never need to remove or even deal with them. I am swapping an e34 m50 motor with a 98 ZF trans in a month or so. I plan on using as much of the m20 clutch system as possible so I dont have to buy anything. I was told I need to shave the oil pan to make the M20 FW fit without issues.
Some have said I need the ZF pilot bearing no matter what.
Some people say that everything should bolt right up, while others say I need a 323 TOB.
If I use the M20's TOB then I need to use a spacer to make this work, what spacer do I need?
Am I missing something here what more do I need to buy to make this work? I think Ive spent to much time reading and have confused myself here.

[ForcedFirebird]

Forget what your read on the internet for the most part. People mis-match so much that it gets confusing.

Simply put, the pilot needs to match the trans. ie ZF is an e36 328/m3, so purchase the pilot for that.

Starter needs to match ring gear on flywheel. So purchase the starter for the FW you have.

Slave matches trans.

TOB matches clutch set (BTW m50/s50/m20/m42 use the same depth). *note* "some" people had issues with the dual mass m20 to SM conversion on the TOB. The only DM m20 FW I have seen is the late eta.

The m20 FW has a large protrusion on the engine side that will contact the RMS housing on a 24v (or m42), so you can either shave the FW, shave the RMS housing, or some people put the bolt ring on the back of the FW (the 6 bolt ~3mm thick ring that goes on the clutch side of the FW normally).

Best thing to do in your situation is use the entire 24v system. The only thing you would have to purchase outside wear items is a FW.

[CaffeinatedSoul]

So just to clarify, M20 Clutch, PP, FW, & Starter. ZF Pilot bearing and Slave for my system?
Btw, thank you for the simple break down on that.

[M3PO]

So just to clarify, M20 Clutch, PP, FW, & Starter. ZF Pilot bearing and Slave for my system?
Btw, thank you for the simple break down on that.

Yes, and the M20 TOB.

[CaffeinatedSoul]

Awesome, thanks for the help

[iitsMikE30]

Forget what your read on the internet for the most part. People mis-match so much that it gets confusing.

Simply put, the pilot needs to match the trans. ie ZF is an e36 328/m3, so purchase the pilot for that.

Starter needs to match ring gear on flywheel. So purchase the starter for the FW you have.

Slave matches trans.

TOB matches clutch set (BTW m50/s50/m20/m42 use the same depth). *note* "some" people had issues with the dual mass m20 to SM conversion on the TOB. The only DM m20 FW I have seen is the late eta.

The m20 FW has a large protrusion on the engine side that will contact the RMS housing on a 24v (or m42), so you can either shave the FW, shave the RMS housing, or some people put the bolt ring on the back of the FW (the 6 bolt ~3mm thick ring that goes on the clutch side of the FW normally).

Best thing to do in your situation is use the entire 24v system. The only thing you would have to purchase outside wear items is a FW.

Nicely done, sir.

[f4tj0n]

This should honestly be stickied.

[ForcedFirebird]

Yes, and the M20 TOB.

Any TOB will work, as I stated before, m42/m5x/s5x/m20 all use the same depth TOB.

M20 TOB part number: 21517521471

Cross references:

Part 21517521471 was found on the following vehicles:

• 3' E21   (02/1975 — 12/1983)
• 3' E30   (12/1981 — 02/1994)
• 3' E36   (11/1989 — 08/2000)
• 3' E46   (04/1997 — 08/2006)
• 1500-2000CS   (01/1966 — 01/1972)
• 5' E12   (02/1972 — 07/1981)
• 5' E28   (09/1980 — 12/1987)
• 5' E34   (03/1987 — 06/1996)
• 5' E39   (02/1995 — 12/2003)
• 2.5CS-3.0CSL   (04/1971 — 11/1975)
• 6' E24   (10/1975 — 04/1989)
• 2500-3.3Li   (08/1968 — 02/1977)
• 7' E23   (10/1976 — 06/1986)
• 7' E32   (10/1985 — 04/1994)
• 7' E38   (07/1993 — 07/2001)
• X5 E53   (08/1999 — 09/2006)
• Z1 Roadster   (07/1988 — 06/1991)
• Z3 E36   (12/1994 — 06/2002)
• Z4 E85   (01/2002 — 11/2005)

[M3PO]

Yep, just tryna make it simple/clear for him.

Any TOB will work, as I stated before, m42/m5x/s5x/m20 all use the same depth TOB.

M20 TOB part number: 21517521471

Cross references:

Part 21517521471 was found on the following vehicles:

• 3' E21   (02/1975 — 12/1983)
• 3' E30   (12/1981 — 02/1994)
• 3' E36   (11/1989 — 08/2000)
• 3' E46   (04/1997 — 08/2006)
• 1500-2000CS   (01/1966 — 01/1972)
• 5' E12   (02/1972 — 07/1981)
• 5' E28   (09/1980 — 12/1987)
• 5' E34   (03/1987 — 06/1996)
• 5' E39   (02/1995 — 12/2003)
• 2.5CS-3.0CSL   (04/1971 — 11/1975)
• 6' E24   (10/1975 — 04/1989)
• 2500-3.3Li   (08/1968 — 02/1977)
• 7' E23   (10/1976 — 06/1986)
• 7' E32   (10/1985 — 04/1994)
• 7' E38   (07/1993 — 07/2001)
• X5 E53   (08/1999 — 09/2006)
• Z1 Roadster   (07/1988 — 06/1991)
• Z3 E36   (12/1994 — 06/2002)
• Z4 E85   (01/2002 — 11/2005)

[ForcedFirebird]

Yep, just tryna make it simple/clear for him.

Sorry if my post was not :/ ...

TOB matches clutch set (BTW m50/s50/m20/m42 use the same depth). *note* "some" people had issues with the dual mass m20 to SM conversion on the TOB. The only DM m20 FW I have seen is the late eta.

[CaffeinatedSoul]

Both posts cleared it up for me. Thank you for all your help guys, it's much aprittiated.

[M3PO]

Sorry if my post was not :/ ...

Nope, it was! Some people around here don't do well with options and just want to be told what to do lol (not you OP, just in general!)

[Mushroom Stew]

Hey I'm doing the same thing, although I am stick with the getrag 240 that's in my car. So to do the m20 flywheel conversion with an e36 m50tu/getrag 240 I would need:

M20 Clutch, PP, FW, M20TOB & Getrag 240 Pilot bearing?

The internet seems to indicate there are two different styles of Getrag 240. I have a 1990 318i- any idea which one I have? Does this effect which pilot bearing I'm supposed to use?


Sorry if I'm missing the obvious. This is all completely new for me.

[ForcedFirebird]

Hey I'm doing the same thing, although I am stick with the getrag 240 that's in my car. So to do the m20 flywheel conversion with an e36 m50tu/getrag 240 I would need:

M20 Clutch, PP, FW, M20TOB & Getrag 240 Pilot bearing?

The internet seems to indicate there are two different styles of Getrag 240. I have a 1990 318i- any idea which one I have? Does this effect which pilot bearing I'm supposed to use?


Sorry if I'm missing the obvious. This is all completely new for me.

You will also need the m20 starter, or swap the nose cone/gear from one to your m42 starter if you can't find a small body m20 starter.

The pilot should be the larger diameter (same as a 24v), the g260 uses the smaller pilot.

If using a stock m20 flywheel, you will run into clearance problems where the back of the FW hits the rear main seal housing. I have done two things to remedy this, one is to shave the housing a little, the other is have a machine shop remove the extra weight behind the ring gear to clear.

Two other ways I have heard is to put the 6 hole bolt ring behind the FW (against the crank), or having a machine shop swap the starter ring gear, but I haven't personally done either. I prefer to follow the KISS rule and make it so stock parts are easy to replace.

[Mushroom Stew]

You will also need the m20 starter, or swap the nose cone/gear from one to your m42 starter if you can't find a small body m20 starter.

The pilot should be the larger diameter (same as a 24v), the g260 uses the smaller pilot.

If using a stock m20 flywheel, you will run into clearance problems where the back of the FW hits the rear main seal housing. I have done two things to remedy this, one is to shave the housing a little, the other is have a machine shop remove the extra weight behind the ring gear to clear.

Two other ways I have heard is to put the 6 hole bolt ring behind the FW (against the crank), or having a machine shop swap the starter ring gear, but I haven't personally done either. I prefer to follow the KISS rule and make it so stock parts are easy to replace.

Thanks for your help. I forgot about including the starter and yes, Ill definitely go get an m20 starter as well. Sorry for being way to new to this but when you state I should be using a larger diameter pilot (same as a 24v), I take it that means I need to find an e36 pilot bearing? or can I just order the pilot that normally goes with the getrag240? I'm having a shop do the work, but I just want to make sure I have all the parts sorted out first.

I will definitely have a machine shop take a bit off the flywheel. Getting very stoked on this set up!