Just replaced the flywheel, clutch, pressure plate and throw-out bearing in the '67 400/M-20. Took five hours. Now, the clutch pedal feels GREAT, adjusted very well. Car sounds good in neutral and pedal feels normal. But, the clutch never disengages; can't put it in gear with the engine running. Start it in gear with clutch in and brake on and there's a nasty whining. Almost seems like the clutch disc is on backward, but it was printed right on the disc "This side to Flywheel." Also made sure that the bearing was clipped into the fork properly. This car makes me crazy; every simple task turns into a pita. Any suggestions?
Hmmm. Was there a problem that made you change the clutch? Hate to say it, but it sounds like the problem MAY be the trans itself. Give us some more input.
bird67conv, Did not change out the pilot shaft bushing because we just had replaced it a few months ago and didn't want to add another variable to the mix. Fbody69, Trans worked well when we pulled it and we did not open it up, except to re-seal the input bearing cover and add 90w. Project was to replace the flywheel, which was way worn and grooved, and clutch slipping. New clutch is 11"; old was 10.4"
Maybe it's a pressure plate issue. When you went to a bigger clutch plate it may not work with that pressure plate. Since that's the only new variable.
One thing I know that would help MarbleCreek Mike out; A picture of the original 4 speed shifter and the stock hole in the floor. He's installing a 4 speed.
The clutch hub may not be sliding freely on the transmission splines. If it doesn't slide freely on the splines, it will be held against the pressure plate or flywheel enough that it won't disengage. This can happen if there is a burr or damage on the transmission input shaft or on the clutch hub. The clutch can also hang up on the spline if the transmission weight dangled on the clutch during installation. That would distort the hub so its no longer true to the clutch disk.
You say the flywheel was worn. Is the replacement flat and true?
If you start the car in gear with the clutch pushed in, does the clutch otherwise operate smoothly?
68Bigbird, Good Point. We had that problem two years ago and found that the input shaft was twisted (didn't notice he twist when we bought the M-20 at a swap meet). We replaced the input shaft and fixed that problem, but the symptoms were similar. Starting in gear with clutch in presents nasty whining, that does not change a whole lot when engaging the pedal. Pedal feels fine. We will be pulling it all out again on Monday, Jan 2, unless we can get to it sooner.
68Bigbird, New flywheel seems perfect, although it's different from the old one. I'm suspecting that the center is not as deep as the old one and possibly the clutch hub is rubbing on the flywheel bolts. I don't remember if there are washers on those bolts or not.
Yeah, that would do it. Years ago I read about someone who added extra washers under the bolts for some reason. I had forgotten about that. It was in one of those "Say Smokey?" columns I think.
Did you use new bolts? If so, is there any chance they have taller heads than the original ones?
Does the whining go away with the transmission in neutral and pedal up?
I guess it has to come apart anyway. If the bolts are standing to high, you'll see the marks.
FIXED!!! It was the flywheel bolts. They worked just fine with the old, GM flywheel. The new aftermarket (C.A.T.) flywheel has a shallower recess where the bolts go. Spent an hour (hard bolts) on the grinder and everythings as smooth as can be. Thanks for the input, folks.
