coffeee

During hard acceleration from a stop, my drive shaft contacts the upper surface of its support. This happens just aft of the center support bearing where the drive shaft splits into two pieces. All of the U-joints feel solid. Maybe a shot motor mount? Transmission mount? I can't figure it out, here's a little recent history of the maintenance i've done. Here's the pertinent drive maintenance i've done within the last thousand mile. Removed and replaced rear main seal, flywheel, clutch, all fluids, center support bearing, rear U-joint just forward of axle. She purrs at 55.
The truck 1989 extended cab pickup,
22re 5 speed 4x4 31's

jb451

Not real knowledgable on the trucks, but it sounds like your back springs and shocks are shot, allowing the rear end to move (or "squat") too much when you mash the gas, therefore cause the driveshaft to contact somewhere. Or, a shot mount is causing the drivetrain to tweak some and move in the front. I assume you already looked at the mounts and the condition they are in? None torn or missing right?

Polaris2012

Did this happen right after installing the new center bearing? I had the same problem bought a cheap (well kind of still 80 bucks) center bearing I tried fliping It the other way still did it. Took it back and went to my local driveline shop he sold me a different center bearing looks just like the stock yota one but it was 100 dollars vs the yota part which was 380. Installed it and the problem went away. Make sure you get it on the right way. If its backwards it will still do it. Hope this helps you!!

coffeee

I took a look at the tranny mount and engine mounts they looks solid. I honestly wouldn't be surprised if the back end was shot. I've been piecing this thing back together ( michigan) truck. The support bearing was about 80 bucks. Maybe ill just have to bite the bullet and get the premium one. I will be doing another round of maintenance here soon enough and ill let you guys know. Thanks for the quick replies. Kris

coffeee

I forgot to say this manifested itself after I changed out the clutch. Thats why I thought maybe an engine mount. I had my engine sitting on a jackstand for a week. I think its gonna get a whole round of u joints and carrier bearings

Punchy

Had the same problem, Changed the Center bearing and still did it (I also reinforce my center bearings with old fanbelt slipped around the inside).
I had to make 1/2" spacers and lowered the centerbearing down.

After I did the auto to manual conversion the replacement shaft from a 89 manual V6 EC was about 1/2"-1" longer and did not hit.

If you have alot of axelwrap it will cause the centerbearing bolts to hit.

coffeee

I added a few washers between the carrier bearing and its support, and that seemed to lessen the issue. I might just have to add a few more. Not to sure what you mean by axlewrap? Thanks again for the reply.
Kris