Early E30 Slave failure with M50 Flywheel

[Kerrath]

About 500 miles of driving after my swap and my clutch is dead. Went to bleed it and on the second set of pumping, it juiced brake fluid out all over the place. I'm thinking that it could be overextending due to being used with an M50 flywheel.

1986 325e
E34 M50 flywheel
Getrag 260
Getrag 260 slave

Any thoughts?

[M-technik-3]

So you used the dual mass M50 setup? any reason for that method?

[Kerrath]

At the time, I had an early m20 starter, m50 starter, m20 dual mass, m50 dual mass. I wanted to get it in that day, and since the early m20 starter didn't fit, went with the m50/m50 combo. It's always worked fine though, til just recently.

I dunno whether the slave was just at the end of its time, or if the use with the m50 wheel/plate overextended it, but that's what I'm trying to find out.

RealOEM shows the e36 and e30 slaves being the same lengths, but the mounting point on the E36 seems to be farther back, moving the piston forward? Any knowledge about that?

[M-technik-3]

So the slave is the old one correct? Just get a new M50 one, they are not expensive.

[Kerrath]

Right, they're not, but first off, do you know if it actually fits? Not too far forward offset, or goes into the bellhousing? Also, the E36 and E34 slaves have different specs at realoem, I dont know what to make of that.

Thanks so far.

[M-technik-3]

I need to look at the slave that was in mine. Think I used an E34 as the transmission came out of one.

How many miles was on the old unit? The snap ring just fail and the shaft popped out correct?

[mattdk318i]

I believe the M50 one is a bit longer. I ended up using a single mass M20 flywheel. But having the M20 and M50 slave side by side. There seemed to be a small length difference.

[EtaSport]

I recall people questioning this issue in the past, I have used both m20 and m50 flywheels in my g260 all using the original e30 slave, I have never had a problem even after 40k or better miles. Is there no pedal pressure at all? Sounds like it is just a slave or master issue.

[mattdk318i]

I recall people questioning this issue in the past, I have used both m20 and m50 flywheels in my g260 all using the original e30 slave, I have never had a problem even after 40k or better miles. Is there no pedal pressure at all? Sounds like it is just a slave or master issue.

I would agree. I dont thing that small distance would make that big of a deal. Probably just a faulty slave.

[EtaSport]

I hate when maintainence problems creep up after doing something big like a swap, I start to see the logic why some people like to replace everything even if it pushes the build time way back.

[Kerrath]

Like I said before, the slave cylinder is at fault, proven to me when it started gushing fluid after the first set of pumping. From what you guys have said, it sounds like the M50 (e34 or e36?) slave cylinder is recommended for use with a single mass flywheel, but the e30 should work find with the dual mass?

[rThor432]

Fro what it's worth, I've used my standard M20/G260 slave cylinder from my formerly dual-mass eta for about a year now with my light single mass 240mm (S50/52) flywheel.

The offset/thickness of the single and dual-mass flywheel for any given motor should be the same, ie. a single-mass flywheel designed to replace the dual-mass on an M50 is the same thickness because they are designed to use the same clutch, pressure plate, and throw-out bearing.

So I'd guess the standard 260 slave cylinder will work just fine for your application and I'd bet that the old one just crapped out. But that's my opinion based on what I've messed with.

[z31maniac]

I hate when maintainence problems creep up after doing something big like a swap, I start to see the logic why some people like to replace everything even if it pushes the build time way back.

I don't understand why the slave isn't something people replace everytime they do a clutch. It's dirt cheap, and the few times I didn't do the slave with the clutch, I had to do it not long after.

[Kerrath]

I don't understand why the slave isn't something people replace everytime they do a clutch. It's dirt cheap, and the few times I didn't do the slave with the clutch, I had to do it not long after.

Well, in my case I was in a big hurry. Had a deadline to get it done by and didn't have the time to order a new one. I guess at the time, I also wouldn't've considered it to be a part likely to go bad. In any case, I'll be replacing it now and it's really not a big deal. Just gotta make sure I get one that'll definitely work and now that that's cleared up, I'll be ordering a new slave cylinder tomorrow. :D

Thanks for your help guys. I really appreciate it.

[Kerrath]

Alright, well, installed the new slave, and the old one's seal was visibly gone. It looked kinda like it either blew out or had gotten pulled inward in one tiny section. In any case, no wonder it was shot.

It works with the replacement and I was able to drive it a few blocks just fine (washing it before driving it more tomorrow) but my friend said that it felt like the release point was very low compared to his and every e30 he's ever driven. Well, I drove his just to get a comparison and he was absolutely right.

Is it normal to have that low of a release point in etas or am I having some unknown issue still? Please tell me how your clutches feel. Thanks!