crushingday

My '78 US 5 speed developed a noise when the clutch pedal is pressed and as is comes back up. (see video link) I noticed the reservoir was low and I can not see where the leak is coming from or where it is going. My foot has not been "getting wet" and I do not see any fluid coming down from the master inside the car or on the boot there either.
there are no obvious leaks that I can see under the hood at the fluid reservoir. although the master does look old with flaking paint and the seals from the reservoir to the master may be iffy. I know I need to look into it further and provide more info to narrow it down, but I was wondering if the video I have attached is a "tell tale" to any one who has heard these sounds.

https://photos.google.com/share/AF1Q...RSSGpRUzduMnpB

Imo000

In the video looks like the noise happens when the clutch is almost fully depressed. Almost as if the release bearing arm starts rubbing the pressure plate.

SeanR

That's a mechanical issue not related to the hydraylic system. Some questions need be asked first. How old is the clutch/throw out bearing and pilot bearing. Do you have a good clutch arm ball cup on the arm? Any ideas if the clutch has been serviced?

Those will help narrow it down but if it were here, I'd be pulling the clutch out of the car and inspecting the entire assembly.

crushingday

clutch/throw out bearing and pilot bearing are about 9 years old with 15k on them. I am not sure a bout the ball cup. Is that the one that is under the lower airbox housing that I can do fairly easily myself? I had noticed some sketchy shifting ( some slight grinding at times) Could this be ball cup related?

Dave928S

I agree with Seans recommendation .... to make sure everything is as it should be, it would be far better to take the clutch out and check the whole assembly (which is not all that difficult). Sounds mechanical to me too.

The ball cup on the release arm is the one under the airbox, but your shifting issues could also just be clutch intermediate plate adjustment, or the rear coupler bushes, or front ball cup on the shifter assembly, or gearbox synchros ... or a combination of any of those.

Not trying to scare you with all the possibilities, just pointing out that you need to approach this in a methodical manner and go through a checklist logically.

If it was me I'd be pulling the clutch assembly (which obviously has some issue) and getting that spot on, and also making sure that the shifter assembly was right.

checkmate1996

Pull Clutch - imho the most likely issue in priority:

- TO Bearing
- Pilot bearing
- Intermediate plate alignment issue
- Clutch fork cup

crushingday

Thank you all for your help. Mark Kibort who is not allowed to post PM'ed me and was helpful also.
I have a good friend who is a 30 year BMW mechanic and lives right down the street. is this something he could do? , or do I REALLY need an experienced 928 guy? I know there are some specifics with the early '78s that need to be tended to here. Is there a procedure I can print out for him to help him and me do this job?

Imo000

Mark got banned AGAIN?

checkmate1996

The double disc clutch is something you want someone with experience especially in how to remove, disassemble, put together and properly go through the alignment procedures for the intermediate plate. A poorly adjusted clutch can kill your clutch life quick. This was one of the reasons why Porsche went to the single clutch due to technicians not adjusting properly. There are tons of articles on rennlist. Search is your friend. It's a solid two person job especially for a newbie. Some special tools involved. Good luck!

Wisconsin Joe

Really?

I had no problems with it (other than the short shaft being stuck in the pilot bearing), and the only "special tools" I needed were the shims for the rivets. Well, that and the "rattle gun" to get the short shaft loose.

The WSM has pretty good instructions on removal, disassembly and replacement. Dropping the clutch on a 928 is the simplest and easiest I've ever done. Having an extra pair of hands was helpful, but neither of the people (one helped remove, another helped install) had any 928 experience.

Disclaimer - I didn't have to do any sort of adjustment/alignment on the intermediate plate. It worked just fine simply installing it as was.

crushingday

I am not sure of the condition of the ball cup, I got a new one from roger and I am going to try to put that in today. I undertand I nee to remove the lower airbox housing and it should be down there on the passenger side(US cars) Is this fairly straight forward? or are there any other tips?

Mrmerlin

release arm bushing goes in from the driver side,
Remove the slave, pull the arm off the ball,
then clean out the arm cavity,
with a long prybar and block of wood pry the bush onto the ball,
then slip the arm on the bush.
refit the slave

crushingday

Thank you Stan.