#@~$%*^ £&#@! Clutch slipping.

[Ferret]

Ok, so you help someone and get shat on for doing it by karma, I think towing back that other E34 has finished off my clutch.

Is the clutch pedal/etc adjustable at all? It's got to the point where it's minorly slipping, you just have to touch the clutch pedal (and I mean literally just touch) and it lets go.

Thing is, it was replaced 18-24 months ago...

Any thoughts gents?

[Ferret]

I should clarify this - the clutch is letting go when the car's cold most of the time.

After the car's warmed up the clutch grips normally - rather than the normal clutch failure routine, this actually feels like the clutch pedal isnt retracting properly.

I find it very hard to believe that it's worn down completely in less than 2 years!

[bsell]

I should clarify this - the clutch is letting go when the car's cold most of the time.

After the car's warmed up the clutch grips normally - rather than the normal clutch failure routine, this actually feels like the clutch pedal isnt retracting properly.

I find it very hard to believe that it's worn down completely in less than 2 years!

This is a hydraulic clutch, right? If so, your symptoms are the reverse of a poorly-adjusted clutch pedal push rod. As in, adjusted to be too long, which closes off the hole to either the reservoir or the pressure line to the slave when hot and builds pressure on the slave, releasing the pressure plate some and causing clutch slippage.

I take it the clutch starts engaging somewhere near the floor with a normal 'bite' range. I doubt it as you say that damn-near breathing on the pedal makes the clutch slip. So, either the friction disk is toast and/or the pressure plate has lost its spring or the whole rig is out of spec.

Did you have the flywheel ground during the last clutch job? If the machine shop failed to resurface both the friction area and the pressure plate mounting area then the flywheel is not at factory specs...and set this clutch up to fail early.

Brian

[whiskychaser]

So, either the friction disk is toast and/or the pressure plate has lost its spring or the whole rig is out of spec.

Brian

x1
Or its burnt out or got oil on the friction plate. I dont have a manual but doesnt the slave cylinder drop clutch fluid into the bell housing if it leaks?

[Ferret]

x1
Or its burnt out or got oil on the friction plate. I dont have a manual but doesnt the slave cylinder drop clutch fluid into the bell housing if it leaks?

Guys, the clutch starts to engage half way up the pedal travel, and has a 'bite' point that's half the travel range!

Any ideas?

[Ferret]

Okay, very strange, posting just got screwed up on this site...

[Ferret]

I doubt it as you say that damn-near breathing on the pedal makes the clutch slip.

The clutch releases with less than 10mm travel on the pedal, I'd call that "damn-near breathing on the pedal makes the clutch slip."

It starts to bite half way up the pedal travel though, I'm starting to think the friction disk may be glazed.

[bsell]

The clutch releases with less than 10mm travel on the pedal, I'd call that "damn-near breathing on the pedal makes the clutch slip."

It starts to bite half way up the pedal travel though, I'm starting to think the friction disk may be glazed.

This sounds like the disc is warped from the heat of slipping. The warpage tends to hide how much friction material is missing by taking up the space left behind by the missing friction material. Does that sentence make sense?

In other words, the warpage gives some bite near the normal engagement point yet can't stand any pressure reduction without slipping.

Did you get the flywheel ground to remove hot spots during the last clutch job? If you do it this time around, make sure the machine shop gets it right. I don't have the specs for the flywheel but somebody around here probably does...

Brian

[whiskychaser]

Guys, the clutch starts to engage half way up the pedal travel, and has a 'bite' point that's half the travel range!

Any ideas?

You only get about half an inch of bite on an HGV so something isnt right. Any chance the release bearing is jamming and not allowing the clutch to return properly? They are only held on to the lever with a wire clip but its unusual for one to slip. Never known anybody have to replace the lever itself. Well, until last week when I saw somebody buy one at my local BM dealers. Is it worth having a look at how much travel you have got on the lever?

[Paul in NZ]

does the 540 have a dual mass flywheel?I have heard that they cant(shouldnt) be machined.

[Barney Paull-Edwards]

First off try bleeding the slave cylinder properly.If you can get under the car drill a hole so that it faces the plate somewhere near the edge.Place a small pipe(bit bigger than a WD40 pipe) push it just through the hole and give the clutch a good squirt of de-greaser and try car.If it still slipping and if all else fails a good dose of Coca-Cola will clean off crap better than anything else.

[Ferret]

Did you get the flywheel ground to remove hot spots during the last clutch job? If you do it this time around, make sure the machine shop gets it right. I don't have the specs for the flywheel but somebody around here probably does...

Unfortunately the clutch job was done for the previous owner - I have no idea as to the state of the flywheel until it gets removed off the car.

[Paul in NZ]

this happened to a freind with a e 39 540 too.the flywheel either hadnt been machined or hadnt been machined properly or the dual mass cant be machined....

[GS535i]

In rare cases, the slave cylinder push rod is not fully seated into the cup of the release lever ( or the cup of the slave itself, depending on the design): were that the case, there would always be excessive pressure applied to the pressure plate ...... taking only a small movement of the pedal to release the clutch.