S52/ZF 320 Slave cylinder issues

[johnjohnsons54]

My e30 has an S52 swap paired with a ZF 320 transmission from a 97 M3.

For whatever reason the PO left the slave cylinder from the old Getrag in the car. The result is a clutch engagement point that is millimetres off the firewall and a "wap wap wap' kind of noise when the car is in neutral and the clutch pedal is not depressed.

So I ordered the appropriate slave for the ZF320 and had my shop try to swap them out. They can't seem to tell me what exactly the problem was, but the claim to have had plenty of trouble bleeding the system and for what ever reason "it just didn't work". That being said, I asked afterwards and they didn't use a power bleeder.

According to the PO there is a new:
E36 Sachs puc sport clutch and pressure plate
OEM new flywheel bolts
Sachs throw out bearing
E36 m3 drive shaft
Pilot bearing
Resurfaced flywheel

Has anyone else had issues with their slave after a s52/ZF swap? Any idea what the problem could be? Might it simply be that the system was not bled properly? Might the flywheel have anything to do with the issue? I'd love to find a solution without having to drop the transmission if possible.

Any input would be appreciated...

[e30rapidic]

My catch point is a lot lower with the zf than it ever was with the Getrag. I had to take my clutch stop out...no need for it now!

I have the zf transmission with the 328i slave. Stock e30 flywheel and Clutchmasters Stage II disc/pressure plate with a stock e30 throw out bearing. I have always removed my slave and press it against the transmission to bleed, then install. I've never had an issue with air in the clutch line.

Unfortunately I don't think there are any solutions to your dilemma without removing the transmission but hopefully I am wrong. A low catch point is common but not sure about the noise you are describing.

[7pilot]

I have bled a couple examples of this combination.
I tried the reverse injection bleed method with no result.
I did the power bleed from above without result.
What ended up as the best technique was a two man bleed with frequent tapping on the body of the slave cylinder.
This got us some pedal, but the return spring would go over center leaving the pedal on the floor.
We left it alone for a week before we found the time to work on it again. A week later without sitting, the pedal was slightly better yet but marginal. However, the pedal would return instead of staying on the floor.
We then did another two man bleed without further progress but the clutch would work ok.
Left it sitting for another week and the clutch hydraulics had self bled leaving a decent pedal which became good after a week of just driving.



In Summary.
two man bleed with tapping on the slave cyl, sit for a week, 2 man bleed with tapping, sit for a week. Drive the car if the pedal is good enough to come back up and work the clutch.
Not time efficient , odd, but successful.

m

[johnjohnsons54]

Thanks for the input so far fellas.

The tapping noise is apparently a result of a cylinder or something inside the slave being slightly too long and tapping against something else when the clutch is not depressed. With the getrag slave installed, the car actually shifts fine....albeit very close to the firewall, which I don't even mind.

I'd really just like to get rid of the annoying sound in neutral and know that everything is right. It's just one of those little things that pisses you off.

I'll try these more creative bleeding techniques and report back....I'm hoping that's all it is.

[Boosted E30]

Already tried the 2 man bleed with no luck.
Gravity bleed works on the getrage slave but not the zf slave.
With the zf slave installed and bleed the same way as i do every single other slave, you cannot put the trans into gear. I just does not dissengage the clutch enough. I honestly spent 2 hours trying to get it to work. Finally i gave up reinstalled the getrage slave bleed it and it worked. The engagment point was right on the floor and weird noises from the trans. It sounds like the release bearing is not in the fork properly, or the retaining spring for the release fork broke and now the fork or throw out bearing is now rubbing on the clutch release fingers.

If anyone has some ideas lets hear them, either the zf slave Scott recived was faulty out of the box or there is a problem inside the tranny.

[328ijunkie]

No matter what the ZF slave should have bled. Its a shitload longer overall from install point to tip vs the 260 slave.

Sounds like something is up in the bellhousing because if youre using a ZF trans a 260 slave should NOT work.

[treff-7]

I'm using UUC flywheel and M5 clutch-pressure plate-TB-M3ZF slave. It feels just like the getrag with the m20.
Bleeding was no problem. i pushed the clutch to the floor and left it there and tapped the hose until no more bubbles came up. then pushed it a couple times, left it up and did it again. I repeated this until i couldn't get any more bubbles out. then i went under the car and bled the line and slave with my nephew pumping the pedal. After this the grabbing point was still a little bit low but improved as i was driving the car. after about a week it settled down.

[Boosted E30]

No matter what the ZF slave should have bled. Its a shitload longer overall from install point to tip vs the 260 slave.

Sounds like something is up in the bellhousing because if youre using a ZF trans a 260 slave should NOT work.

This is exactly my thought and what has me scratching my head.

[nrubenstein]

Did the ZF come from an E36? Using the clutch fork from a self adjusting clutch (say, E46) will make it impossible to disengage the clutch.

[Boosted E30]

The PO who built the car says he put all "new" e36 m3 clutch parts in there when he did the swap. But some how it doesnt add up because it doesnt work together as it should.

[cormier]

Sounds like something is up in the bellhousing because if youre using a ZF trans a 260 slave should NOT work.

This combo wont work? You have me worried-- the UUC st2 flywheel says to use the 325 slave which I have installed ready for my swap, hope I won't have a problem

[johnjohnsons54]

Thanks for chiming in Nick.

I've got another slave cylinder on order just in case but I find it unlikely that it was the problem. Might have to drop out the transmission after all. Sheeeeit!

Already tried the 2 man bleed with no luck.
Gravity bleed works on the getrage slave but not the zf slave.
With the zf slave installed and bleed the same way as i do every single other slave, you cannot put the trans into gear. I just does not dissengage the clutch enough. I honestly spent 2 hours trying to get it to work. Finally i gave up reinstalled the getrage slave bleed it and it worked. The engagment point was right on the floor and weird noises from the trans. It sounds like the release bearing is not in the fork properly, or the retaining spring for the release fork broke and now the fork or throw out bearing is now rubbing on the clutch release fingers.

If anyone has some ideas lets hear them, either the zf slave Scott recived was faulty out of the box or there is a problem inside the tranny.

[Boosted E30]

Yea it sucks having to pull it out but honestly that would be best, there is something broken inside causing the noise and that needs to be addressed.

[johnjohnsons54]

If anybody is interested, I found this thread while searching for other guys with similar issues.....it's 2 pages, and sounds like the release fork and/or pivot pin were the problem.

At this point, I don't really have good reason to believe that my car has the exact same problem, but this guy is running all the same parts that are in my car....

http://www.bimmerfest.com/forums/showthread.php?t=605869

[johnjohnsons54]

Did the ZF come from an E36? Using the clutch fork from a self adjusting clutch (say, E46) will make it impossible to disengage the clutch.

I honestly can't tell you for sure my friend but I think you could certainly be on to something. Is there any way to tell whether it's from an e36 vs e46?

It's also my understanding that running an e30 flywheel on a ZF tranny will effect the distance between the slave and the clutch. I honestly don't know exactly what type of resurfaced flywheel is in the car but suspect it could play a factor.

The PO is a solid guy based on my interactions with him, but I get the feeling he's pretty much done with helping me figure out the car's issues. I understand.....I've sold cars and businesses in the past and it gets old in a hurry when the new buyer keeps pestering you.

I think I'll give it one more try with the new slave and then it's back to Nick to pull the transmission. I can guess all day based on things I've read on the forums but ultimately I think we're just going to have to take a look.