Driveline Guru's anyone have adjustment specs (driveshaft center bearing adjustment)

[55Designs]

if anyone has followed my posts over the last few months our car has been plagued with a bad driveline vibration. its been a real pain to diagnose exactly the cause but after yesterday its obvious.

We back tracked and checked everything under the cars suspension, rechecked the alignment and rear toe, rebalanced wheels and tires you name it.
December 2009 while the car was mostly stock aside from coilovers and sway bars our local Chevy dealer said they adjusted the plate flanges on the driveshaft because we were hearing noise and resonance. We were not charged for the work and I honestly didn't think they touched anything,

As winter rolled along the car sat and we did more custom work. Roads cleared from snowfall and bingo we have had a massive vibration since. Our car was too modified now for any warranty or dealer service.

So yesterday after dropping the exhaust system and removing the Hotchkis Chassis brace and heat shields we found the following.

1. There is clunking play in the center driveshaft U Joints
2. There is oil and grease scattered all over the tunnel that the shaft center bearing is sitting. The vibration has caused everything to blow apart.
3.The center bearing U bracket which has elongated adjustment holes was tampered with from evidence of socket marking on the 13mm screws. The impressions in this bracket from the head seemed to be totally off from the factory. This adjustment is critical to the degree the shaft spins.

Now we moved the bracket back to see if it would help and it did slightly but I dont think its worth messing around more because we feel the center bearing and U joint are SHOT from driving so long with this out of tolerance.

So guys I might pick up a new OEM driveshaft this week since the aftermarket vendors have nothing or feel confident is building one yet. I need some tech help on how that center bearing needs to be dialed in and gauged so this doesn't ever happen again. I called our Chevy parts department and spoke to the shop foreman and he honestly didnt know himself.

if anyone knows or has a general idea post it up in this thread.

Thanks

[flyby]

My drive shaft has been removed because of new 9 inch rear. I should be getting my nwe two piece shaft this week. If you have trouble getting a new driveshaft, let me know, maybe we can work something out. My guess is that you will have to get a more durable one because the problem and area you described is what happens before failure from what I've been reading.

[55Designs]

Originally Posted by flyby

My drive shaft has been removed because of new 9 inch rear. I should be getting my nwe two piece shaft this week. If you have trouble getting a new driveshaft, let me know, maybe we can work something out. My guess is that you will have to get a more durable one because the problem and area you described is what happens before failure from what I've been reading.

Sending you a PM now

[2SSRS@Gen5diy]

I have the books for the car let me know if you need any info from there.

[55Designs]

Originally Posted by 2SSRS

I have the books for the car let me know if you need any info from there.

Yes for sure. Any chance you can scan sections on the driveshaft an email me directly if so PM, much appreciated. Called 3 more dealers today and they were clueless