bran3b

Are there 2 different clutch forks in early 928s? I have the fork that I took out of a '78 that has a small ball on the stationary side while the replacement that I have from a '79 has a much larger ball and a plastic cup. The replacements online all look like the later '79.

I'm forced to change because the '78 fork doesn't seem to fit the throwout bearing, it is too narrow which seems to have contributed to the original failure.

Wisconsin Joe

Short answer, yes.

The details are in the WSM. starting on page 30-20.(vol 2)

bran3b

That works, with that I was able to find what I was after. Not terribly happy about what I found but at least it was an answer. Time to pull the torque tube and bell housing to press out the old ball.

Thanks for the help.
Brandon

Landseer

You also should know that very early in 78 there was a change made to the length of the actuator sleeve that inserts into the throw-out bearing.

The Deputy

Bran,

Can you show pictures of the throwout bearing in place on the first version arm.

Is the ball-stud toast on your bell-housing? Those are weird marks on the arm itself. Just wondering.

Thank you,

Brian.

GlenL

I'm unclear on what vintage parts are going where and why.

FWIW - Porsche modified the ball stud twice. The final version is what's in the picture: threaded stud with large ball and nylon cap.

If you need to drill the bellhousing, be careful to get the hole straight and to not drift off into the aluminum.

Optimator

I compared a '78 bellhousing to a later one and found that the surface that the ball stud mounts to is not in the exact same fore/aft location relative to the bellhousing mounting surfaces. If I recall correctly, the surface is maybe 6mm closer to the engine on the later bellhousing. This change was likely made in order to retain the same clutch fork/slave cylinder geometry when the change was made to the larger ball stud.

Even though the WSM says to just drill and tap the early bellhousing for the larger ball stud, this would obviously alter the clutch geometry. Would that cause any problems? I did not want to find out, so I just used the later bellhousing.

bran3b

Just catching up now, been fighting with the car most of the day.

I ended up using the newer fork with it's proper bellhousing that came from my the green '79. After reassembling the clutch I realized that I forgot to put lube on the clutch shaft so it all came back apart. Now the clutch feels nice and the car feels much better, on to the transmission which has at least 2 bad syncros.