Testing clutch operation on the bench

[jayson.devries]

I've just replaced the clutch and throwout bearing in my AutoStick gearbox. Before I put it back in the car I'd like to ensure it is operating properly. So on the bench, in gear, I turn the input shaft by hand and the axle flanges turn. Great!  With the clutch arm and servo arm adjusted, I draw a vacuum with my Mityvac hand pump. The clutch arm pulls all the way with the expected resistance. Now I turn the input shaft and.... the axle flanges are still turning! Hmmm..  (scratches head).
 
Have I assembled something wrong? I'm quite certain the clutch fork was positioned between the clutch cover and the TO when I attached the bell housing - besides, the arm moves with the expected resistance. Am I missing something? Any ideas?

[Tom K.]

My process to reassemble the clutch appears on the bottom of this thread

https://www.thesamba.com/vw/forum/viewtopic.php?t=714131&start=40

[jayson.devries]

Thanks Tom - great post and pictures!

I did finally solve this. The only thing that made sense was that the new clutch had stuck itself to the pressure plate and/or the carrier plate. A piece of critical information that I thoughtlessly left out of my first post was that it had been sitting for over a year since I assembled it. Since the oil plan was already attached, I really wanted to avoid opening it up (I gotta start making my own gaskets like you Tom). So I bolted levers to the axle flanges, carefully clamped on to the input shaft, pulled a vacuum on the servo, and tried my damndest to snap it lose... to no avail.

Out of options, I did finally open things up and did find the clutch stuck to the carrier plate. Not so much rust as just clutch material. I'll post pictures tomorrow.

[jayson.devries]

Here are a few pictures of the clutch material (asbestos?!) rusted/stuck to the pressure plate and the carrier plate.

[Tom K.]

Bummer. I had the same issue. I used a razor blade and then light sanding to clean the pressure plate. Pictures appear in one of the first pages on my build thread with link above.