1973 Ford F100

[steve brown]

I have a 1973 Ford pickup with a 3 speed tranny which vibrates badly when releasing clutch. New flywheel,clutch, pressure plate,pilot bearing and throw out bearing has been installed and was no help. I have had this out 3 times looking for problem but everything looks good. I have put an indicator on flywheel and it runs perfectly true. Any help would be greatly appreciated.

[jonmark1985]

How do the U-joints and driveshaft look?

[ABE]

Check engine and transmission mounts too.

[steve brown]

U joints are new.

[steve brown]

Engine mounts are new.

[ABE]

Have you confirmed the transmission mount(s) is/are good? Often the rubber deteriorates badly in that oily environment. If the mount does not hold the trans securely there will be a lot of vibration.

What about the location of the back axle. Have you checked the spring and axle mounts?

Good luck.

[doug 351]

Pure speculation on my part here- Slim possibility that the imput shaft and front bearing on the trans might cause this problem. If you slipped the pilot bearing on the tranny and wiggled the shaft to check for play, you've already eliminated this possibility. The usual culprit for this problem is a bad throw-out bearing or a leak from the trans or motor getting oil on the flywheel. The next most likely cause is a bad trans mount or carrier bearing. One piece driveshaft on yours? Probably one of the easiest things to do is have a buddy lay next to your truck where he can see under it while you take off. He may be able to spot the source and save you some headaches. Offer some beer as incentive if he spots the problem, he may climb under it then while you take off!lol. Works for me.