Hey all I just had 2 rear axel u-joints go out on my '06 with 41,000 miles.

The rear and middle u-joints on my mega were shot. I had a local shop replace them plus the one off the transfer case.

I was getting a heck of a shimmy that was concurent with bad u-joints, and the new joints helped, but I'm still having the same issue but not as bad.

The shimmy is at it's worst at right around 22 mph, and doesn't matter what gear, motor on or off, or if the clutch is disengaged. You can't feel the shake in the steering wheel at all.

I don't think it is the tires because the shimmy is too fast to be tires at that speed.

Is it possible that a front drive shaft axel u-joint could be the culprit? Or is it more likely that the pinion bearing on the rear axel or output bearing on the transfer case is screwed up?

I was thinking the the transfer case output shaft bearings would be okay since the ujoint closest was okay.

Any thoughts?

 

Man. that's a tough one. Since your mileage is 41k you should have a powertrain warranty right? Some years are 36k some are 70K though I'm not sure on your 06. You might PM VZdude, he is very knowleged on these trucks and has helped me a ton.
Good Luck.

Wood

 

drive shaft? double check the two new u-joints- make sure they are installed properly.

 

36k powertrain warranty.

The shaft wasn't damaged in any way, and should be balanced. No weights are missing, etc, or so the shop claims. The truck goes back tomorrow.

BTW, all 3 u-joints were replaced on the rear shaft. They were replaced with greaseable u-joints.

 

Any lift on the truck?

Or auxiliary/overload springs?

Carrier bearing spacers are often effective at correcting pinion angle - thus preventing associated u-joint noise & wear.

 

I also would look at the carrier bearing.

 

Completely stock suspension and tires, the only change has been the 3 new ujoints.

 

Just got the truck back from the shop. They inspected it all day, road test after road test, and while they could feel it they were not able to find any loose or worn componets under the whole suspension.

They looked at the whole front end (ball joints, front knuckels, everything), rechecked all of their work, checked the drive shaft carrier bearing, pinion bearings, etc, and didn't find any thing.

They never charged me for any thing, but they suggested that I try rotating and balancing the tires. The other thing they suggested was to put a few hundred pounds of ballast in the box and see if it goes away.

I'll start with the tires as it is prolly time to do it any way.

 

If they pulled the slip yoke loose at the carrier bearing they may not have gotten it lined back up correctly. The yokes need to be positioned on the same plane or they will be out of phase and can cause a vibration. If they are lined up properly, it could have gotten turned 180 degrees and possibly throwing the balance off.

 

Is this something that I could quickly do my self?

Would it be as easy as pulling the bolts that hold the tail end of the drive shaft to the mounting flange, slide out the rear section and then slide it back in and remount it?

Are there any identifing marks that I could look for?

Is it only possible to get it out of phase by 180?

I've never had this shaft apart, but I have replaced many ujoints on older trucks before.

 

I recommend a half-inch carrier bearing spacer to bring the pinion angle back into spec when driving unloaded - especially since you don't have any anti-spring wrap traction bars.

 

I noticed a squeak in my U-joint on the rear shaft. Only 25,000 miles. Brought it to the dealer under 3yr 36000 mile warranty. They butchered the drive shaft in the process but good enough to drive. I have to go back when they get the part to replace the whole drive shaft assembly now.

Frustrating to say the least.