New clutch slipping in 5000 turbo quattro

[Ben Swann]

After two weeks and extensive work on fellows car – ‘ 86 5000 CD turbo quattro ( Canada
Car), a sick sinking and  maddening feeling came over me when finding that the clutch
was slipping with only moderate power levels.  I reluctantly did a clutch job for him
prior to doing power adders – Supp. Injector, single-pass, 3” downpipe and other mods.
So we were not even able to test and tune for greater power, and hope he could make it
home alright

Clutch disengages completely with only about ½” pedal travel leaving another 2” all the
way to the floor.  Usually when I replace Slave Cyl. I’ve  had the opposite problem and
clutch does not disengage ‘til almost all the way to the floor until extensive bleeding
or the circuit.  I did bench bleed the slave and free air between slave and reservoir,
but nothing with the master. 

We decided to do Clutch work after some test runs showed about 217 WHP and clutch
slipping in 5’th gear.  Removal showed leaking real seal and oil on clutch disk surface,
and release bearing was nearing end of its useful life – so the job had to be done and I
feel I made the right call, even though I really didn’t want to do the job.  So R/R
included turned 5000 flywheel, nearly new disk(about 5000 miles of use and clean
surface/no glazing), decent looking pressure plate (better than what came out). I had
ordered a new disk, but found out they are NLA.  Flywheel had ben lightly turned, and at
least the disk I put in was thicker and not worn, glazed and shabby compared to the one
I took out.   All was cleaned prior to install.  Also I replaced rear main seal, and
release bearing along with the slave cyl – new parts.  The engine went in relatively
painlessly with no jamming – I usually get some, so did not perceive any problems.  Yes,
I did the job removing the engine rather than dropping trans.   Easier for me and had to
service EM, turbo and other engine stuff, and front was coming off for the ’91 200
crossmember and intercooler install.

So after all that labor and parts, why would this clutch be slipping?  I simply can not
afford to do this job again and am pretty much going to eat the clutch job unless there
is a simple cure.  At least maybe I can advise what might prevent having the job redone
with similar problem.

I am upset since I reluctantly agreed to do the job for him at rock bottom price prior
to bumping the power in the car. The only thing I can really think of is that perhaps
some grease from the shaft or somewhere flew up onto the disk.  That happened to me a
long time ago in a Scirocco, and now always use the slightest of white lithium in the
pilot bearing and release bearing, but actually now I’m hoping that it is the cause
since that can be resolved with liberal application of  brake cleaner in the right
holes.

I don’t have the car now as he had to drive back to Canada after advising to stay out of
the power.  He’ll be back in order  to tune the injector controller and enable other
tweaks.   Maybe there is something his local mechanic can check without removing the
trans or engine to check.

Ben