I've searched around, and haven't gotten an answer on this issue yet.

The vibration is most noticeable at higher speeds, but still faintly noticeable at lower speeds. The whole car seems to shake, nothing is really felt in the steering wheel.

I did the 2" shackle lift in rear, so I'm guessing it has something to do with this. I rose the front a little by adjusting the torsion bars. The rear now only sits 1/4" higher than the front. Could this still be an issue with the drive line not being at the proper angle? I also checked for missing weights on the driveline, and that all looks good.

I did also notice, while checking the U joints, when I shook the drive shaft the whole transfer case and tranny moved. Is this normal? The tranny mounts look and feel fine. Didn't really check motor mounts, will do that tomorrow.

It also has fairly new rancho shocks, that aren't leaking or anything. I did also notice that the rear rotors will need replaced soon as they are getting warped. There isn't any pulsating on the pedal yet or anything though. I replaced the fronts already so those are brand new. Could bad or warped rotors cause the car to shake at higher speeds even when the brake isn't being pushed? Like friction issues maybe?

I unfortunately got it aligned before doing the shackles, so I will have to have it done again. I'm hoping this may solve my problem. It never seemed to shake before I did the shackles though. I originally had it aligned because it was pulling hard to the right. Also had all wheels re-balanced today. The vibration is most noticeable at higher speeds, but still faintly noticeable at lower speeds. The whole car seems to shake, nothing is really felt in the steering wheel. It has pretty new 31" tires with a ton of tread left. No abnormal wear on them.

Any help or suggestions would be greatly appreciated.

 

The trans and transfer case shouldnt be moving. Have you at least had your tires balanced?

 

Yes I had all the wheels balanced yesterday.

 

after you put the lift in did you go and get it aligned? that will cause a shake also check your drive shaft make sure its not bent and the weights are still on it. could also be be bad tires.

 

So after some more observations today, I noticed the torque converter dust plate is missing. No idea how long its been off either.

With that being said, could this cause my issue? I've had it in the hills, through car washes that spray undercarriage and what not assuming that shield has been missing the whole time.

So with that cover being off, are there any quick things I should look for to see if its bad now or going bad?

 

Also noticed that it shakes a bit when accelerating hard from a stop. Maybe tranny or torque converter shudder? Doesn't seem to shake at all times.

Also looked at flex plate and it looks good with no missing teeth or cracks. It does seem to wobble a little. Not sure if that is normal or not.

Note: I did also try putting it in neutral while it was shaking. Didn't go away.

 

So another update:

Just had big O tire look over everything, and re-align it. They aren't able to figure it out either, which I pretty much expected unless it really was a wheel issue.

I'm pretty stumped at this point. My best guess is that it's the drive line. But would a 2" shackle lift really cause this? Everything I read said it would be fine, and not enough angle change for drive line.

I don't have much experience with drive lines and these pinion shims I keep hearing of.

Any more input would be greatly appreciated. Maybe my next best bet would be to drop it off at my local drive train shop?

 

you should not need shims with just a shackle lift.

i didnt need them till i did the 5" suspension lift....at that point i went with 6 degree shims.
i ran along time with just a torsion bar and shackle lift...never had any need for them with 2" of lift.

take the drive shaft off and see if the u joints are moving freely...they may be seized up. if they dont move freely you will need to replace them.

most likely when you altered the truck a issue that has been there awhile has been tweaked just enough to show up.

the only thing that stands out is that it is vibrating in neutral....were you rolling at the time? usually if its the drive shaft when you let up the force isnt there to cause issues.

i would take another look at the tranny mount to...have someone help you by shifting it into and outta park and forward and reverse and such....block the wheels so you are not crushed...and make sure they can operate the brakes.

i would do the tranny mount anyway...unless you have had it done or know its good for sure....its a cheap part and easy to do.

hope that helps.

 

Pulled the drive line off tonight and replaced the rear U joint. The front felt great. The shake is still there though.

I think my next project will be the tranny mount. From the looks of it, it seems ok, but when I shake the drive line the transfer case and tranny shake a bit as well. Should there be no movement at all?

Thanks a ton for your help

 

the tranny should be in there pretty solid.