Hi Bob
Glad you got the Newsletter in readable condition. Let me explain Bob is speaking of Tech Tip section of our local MV newsletter were this month we were talking about Sticky Clutches. Now to Sticky Clutch as it appeared - with a few additional pictures
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Tech Tips—-
What’s wrong with the picture at right, and can you guess the symptoms that resulted? This picture was sent in by Jim Miller and came out of Deb’s M151 and yes the spring was loose inside the clutch pressure plate assembly. The result was an intermittent problem with clutch disengagement. Yes, push in the clutch peddle and the clutch would not disengage which makes starting stopping and shifting gears a little difficult.
Now in a couple of ways Jim was lucky in that when he took the clutch apart the problem was very obvious as was the solution replace the clutch disk. What was apparently happening was some times the spring would wedge and the clutch would stick sometimes it would slide and the clutch would work normally.
Intermittent problems can be a real problem to diagnose and correct, particularly when the symptoms present erratically. It is down right reimbursing to be driving along going up and down through the gears and suddenly you start missing shifts. Bad enough when you hear the crunch yourself but worse when they can hear it in nearby vehicles as happened to your editor on the Fall Foliage Ride.
After that trip I decided it was clear that something had to be done. By this time the clutch was sticking almost every time the truck was parked as well as randomly on the road. First step was remove the bellhousing bottom cover and have a look to see anything was obviously wrong. Only thing that I could see was that the clutch plate actually moved back with the pressure plate which seemed a little strange. Next step was go ahead and pull the transmission and clutch to see what was up. Once apart the first thing I check was that yes clutch disk was assembled the correct side to flywheel. (Yes some will go in wrong way around).
I was hoping that I would find something obviously
broken, bent , warped, or rusted no such luck everything looked like it was a relatively new clutch pack (only about 5000 miles) since it was replaced. Next step was to check each component. The pressure plate on Chevy’s have 3 little return springs if one is worn out or broken this can cause the pressure plate to pull back unevenly or crookedly but all three were perfect and new.
The flywheel still had the resurfacing scratch marks from when the clutch had been replaced and was clean with no sign of anything.
The actual clutch disk was flat, no measurable wear, no loose rivets. The only thing that could be seen was some dark areas that felt
sticky, yes sticky to the touch. When I ran my finger tip around on both the flywheel and pressure plate. The flywheel was clean but the pressure plate felt sticky as well.
Cleaned all of the friction surfaces with brake cleaner until the rags came away clean. Flywheel and pressure plate came clean quite easily, taking only spraying and wiping twice. But the clutch disk took a more cleaning including using a soft bristle brush to scrub the recessed rivets clean.
With everything really clean and the spines, through out bearing, and pilot bearing in the flywheel carefully regreased reinstalled the entire unit and hoped for the best. Luck was with me, now after another 200 miles of driving the clutch has not stuck. The only crunch noises from missed shift are my own missed double clutching."
Now to Bobs questions:
So what was that gooey sticky stuff on the clutch plates??? and how did it get there....? how do you know it will not gather again...... ??
I think that the sticky stuff was a combination of old engine oil and clutch dust. In thinking about it after pulling the clutch assembly out I remembered that because it was a relatively new clutch and pressure plate assembly I had not cleaned it. Remember one of the reasons for the overhaul was major rear main oil leak. This time I cleaned the entire pressure plate unit inside and out along with the clutch disk.
So could a full can of brake cleaner sprayed onto and into the clutch pack housing ... with the bottom cover removed..... be a roadside fix....?
Yes I think you are correct the brake cleaner treatment would probably work if as I observed the clutch was actually sticking to the pressure plate and moving back when the clutch was disengaged. so catching it when it was disengaged, or prying it forward, would let you stick the little degreaser nozzel in to spray. This does work with a clutch that is slipping because of oil leaks for a little while.
On another note..... how did you fare out with the latest bad weather..?
We fared OK power was out for three days because the wire was broken in two places in town. Because of the power companies triage system they send all the line crews to the most populated areas first. So people in rural communities are all buying generators. We have generators.
Talking with the line crew that finally reconnected our area, they had just been told to pack-up and drive to Connecticut, New York City area. Its the people down there that I really feel sorry for.
Cheers Phil