hacker-pschorr

I really need the communities help diagnosing this one, everything looks to be in order and setup correctly yet it won't release. Any ideas?

The pilot bearing is properly notchy and difficult to spin too, just the way they are supposed to be.

I'm completely lost here.

Wisconsin Joe

Oh my. That looks...

Interesting.

The 'fun' part is that the TOB is replaceable in the housing. Roger has 'just the bearing'. IF the housing is in good shape, the old bearing can be pressed out and the new one pressed in.

Unfortunately, your issues run deeper than that.

Ahhhhh...

Just slap it all back together and put it in.

What could possibly go wrong.

Mrmerlin

Eric it looks like your having fun, you probably know every bit of what I will be posting, but for clarity ,
for those that might find this thread in the future here are some specific answers.

GB has cranberry colored 300M stub shafts you need one,
buy a new Porsche TOB,
make sure the guide tube is still good, also verify the PP fingers are good
and the release arm has curved faces that run on the TOB
swap out the pilot bearing and maybe the RMS ,get a Good seal, GB sells em with ribs on the edge.
open up the release arm bushing with a dremel so it fits on the ball then press it on then the arm should slide onto the bushing
use the Porsche spline grease use a tooth brush to brush it into the splines of the disc an stub.

Consider replacing the clutch master and slave and the flex hose,
GB makes a nice upgraded flex hose so bleeding is 2 min job. with min fluid loss.
Dont forget to modify the MC piston to 75MM the new ones are 80mm.
you lose some stroke thus the clutch may not fully disengage
also cut off 2 curls of the spring.
NOTE park the car on dry realestate keep off the dirt or grass parking areas,
as this causes accelerated corrosion of the clutch pack

GregBBRD

Looks like someone was "very green" when that one got assembled....no nasty polluting grease used.

As long as you can save the intermediate plate, the rest is easy, at this point in time.

hacker-pschorr

All good advice. Here is my game plan.

Assuming this 78 still had a 78/79 clutch installed, I gambled on an idea to get this car running: rob the clutch from my 79.
While I typically avoid robbing parts from my own cars to fix another, my thought process for this plan was as follows:

• My 79 shifts like butta
• It also has a 78/79 style clutch
• Due to other maintenance items my 79 will be off the road for a while
• I already have a spare double disc clutch of the latest version I was planning on installing someday. Since the 79 is my track car, I figured it should have the latest style double disc and the 78 can stay "original".

Before embarking on this journey I gathered the following parts

• Bell-housing from a later year with the largest ball (and a new bushing)
• Later style clutch arm
• New release bearing
• New pilot bearing
• Replacement clutch shaft (already have a good used one)

Before dropping the clutch I replaced the master / slave since the master was leaking.
https://rennlist.com/forums/928-foru...he-fender.html
The leak gave me hope that was the problem, not so lucky.

When that failed to fix the problem, I had to park the car due to other 928's that were already further apart I needed to work on instead. Toss into the mix a deer hitting our 80, this poor 78 got to spend the next five years waiting for a replacement clutch.

Hopefully 2021 is the year I get to actually drive it more than off the trailer.

GregBBRD

Great plan.
Just make sure that the late model T/O fork isn't the incorrect "09" version.

hacker-pschorr

Good info, it looks like I'm good to go:

GregBBRD

Yes, you are.