Clutch trouble on 1970 F250 with T18 Trans

[Big John]

The Clutch fully disengages but when I go to let off it jerks real bad until I get going. I heard there is adjustments but is that the problem?
If I just need to adjust it how do I go about doing it?

THANKS -Big John-

[390Nut]

Slipping clutch not too long ago? Been doing any power burnouts?

Sounds like your clutch plate is glazed or the flywheel is cracked/glazed.

What's happening is when you let off the pedal, the clutch is grabbing-slipping-grabbing-slipping. Pull the inspection cover on the bottom of the bellhousing and take a look. helps to have someone else to work the pedal for you while you're under there, and have a good flashlight. A Mini-Mag (or something else you can focus the beam with) is great for this.

Having someone work the pedal slowly down and up, check the linkage for sloppy movement, make sure the z-bar isn't moving sideways (the bushings on the ends get worn out) and then check the internals in the bellhousing. Get as good of a look at the throw-out bearing as you can, it might be causing this as well.

Check the disk plate for glazing or contamination (oil/dirt) and the flywheel surface for heat glaze also. It will show up as blue streaks at first, but will lead to spider-web cracking of the surface, which is one of the causes of a grabby clutch.

It MIGHT be in the rear differential, but you would likely notice that all the time, not just when you release the clutch.

[Big John]

Thats a negative on the burn outs. But when I bought it the guy said It has been sitting for about 7 years. So when I got her home I changed the transmission and differential fluid an did some motor work. and now that I am starting to drive it I noticed the jerking. I called some people an they thought that there might be some rust on the disk plate and it just needs to be drove. What do you think? I'll check the things you listed for now.

Thanks -Big John-

[390Nut]

Very possible. I noticed a bit of the same thing the first time I drove mine (it had been sitting for almost two years before I got it from the "family" after my dad died; long story).

Anyways, it went away with about 15-20 miles of stop and go driving. If you've got a few miles on it and it doesn't clean up, you might want to take a look at the disk/flywheel/pressure plate. Chances are, the rust was signifcant enough to cause more problems, and grind up the surfaces a bit, making it "grabby".

It could also be caused by a leaky engine rear main seal blowing oil on the internals. A lot harder fix, that one.

[Leadfoot]

sound like you clutch disk has bad torsion springs. they help stop that jerky, jerky. but when they go bad dose the clutch pedal vibrate if so your are likely looking at a new clutch disk.

[Big John]

It doesn't really viborate, the truck just jerks. But I'll pay a little more attention to that.

Thanks - Big John -