Timing the drive shaft? Now have high speed vibration. - fixing the launch shudder

[WarWagon]

I just had a shop replace the 3 u-joints and the center bearing with a poly bearing. The old u-joints were worn but not really failed yet.

After fixing this I get a vibrator like shake from the rear end. Around 60-65 MPH with 4.10 rear end. Makes the keys jingle. I returned to the shop and they rotated the drive shaft 90 from where it was and the vibration is less but still bad.

The launch shudder is less though. This is what we were after as trailer towing was making this bad on launch.

High Impact Polyurethane Cushioned Center Support Bearing:

http://www.iedls.com/page11.html

How do I time to two drive shaft halves? There are only 2 other ways to assemble it at this point. (They was it came apart was marked and the way it is now is 2 ways down...) Other than that is the Poly center support a bad idea? Or maybe I have a dud new U joint?

The vibration is so bad that is makes the service 'transmission' engine soon light flicker on a stop - no codes stored.

 

[ak diesel driver]

my understanding is the yokes have to line up all the way from tranny/tranfer to rear end.

 

[WarWagon]

'ak diesel driver' is correct.

I am being told, from Inland Empire, that I need to use non-serviceable u-joints for towing as the others may allow play at high speed. Also they said they the drive shaft may need to be balanced after changing the u-joints.

So we will see how balancing turns out.

 

[btfarm]

I am being told, from Inland Empire, that I need to use non-serviceable u-joints for towing as the others may allow play at high speed. Also they said they the drive shaft may need to be balanced after changing the u-joints.

So we will see how balancing turns out.

As long as they are willing to keep at it until you are satisfied you're good!