Shaking rear end

[jakeboyce33]

Hello everyone. I've got a '99 K2500 4X4 4 door with a 6.5ft bed. My truck has drums in the back and disc breaks up front. I replaced the rear drums last summer along with the U-Joints on the main drive shaft which is a 2 piece drive shaft. The truck shakes at 47-53mph and at 67-74mph. I also had Goodyear Ultra terrain tires put on in before winter. I've had them re-balanced and the rear end still shakes. Rims are stock size and still in good shape. Every once in a while while going 70mph it's as smooth as a babies bottom going down the road but the bounce eventually comes back. Wheels are tight, I've swapped the front tires to the rear on both sides, on the side it shakes the most I tried a different drum and it still bounced/shook. It's a solid rear axel back there. I'm not sure what else to try at this point? Any advice is appreciated, this is driving me nuts!

 

[scott2093]

When did the shaking start? Was the shaking the reason for the u-joint and driveshaft replacement?
What kind of replacement parts? Who did the work?
Bounce?Shake? Not sure what to make of that description. Anything you can compare it to?.... like...going over the rumble strips on the highway...etc...

 

[Schurkey]

Perhaps a moderator will move this thread out of Engines and into Axles + Brakes.

 

[evilunclegrimace]

Chek your tires for being out of round. Also check your that the wheels are not bent. Check for a bent axle . Check to make sure the drive shafts are in phase. Check for dirt/rust build up on the wheel to axle mating surfaces.

And you have disc BRAKES not breaks.

 

[movietvet]

Like @scott2093 said, did you do the work because of the shake or the shake started after the work? @evilunclegrimace beat me to the spelling correction. If you are gonna ask questions about systems on your truck, please know the name/spelling for the posts.

 

[b454rat]

How old are the shocks? If there completely whooped its like not having any shocks. But that would go with the road conditions. What shape is the carrier bearing in?

 

[movietvet]

I also should have asked. You said it shakes in the rear. Do you feel that in your feet, ass on the seat or both? Any shake in the steering wheel? Have you inspected the carrier bearing, like @b454rat asked? Can you supply pics of the u-joint phasing and the carrier bearing assembly? Has the driveshaft been checked for any impacts and/or balance?

 

[evilunclegrimace]

Another thng to check is the runout on the drive shaft(s) .050 max. Are there any weights missing on the shafts?Has anyone beat on the shaft to change a U joint and dented it at the weld?

 

[GoToGuy]

If you swapped the wheels around, and it's not brake issue, if you have shock adsorber that's lost it's oil , you can hit a bump and the wheel/ tire will start a cyclic bounce ( shaking ) as the spring and tire will act like a bouncing basketball. Have checked shocks? How old ?

 

[Hipster]

Why U-joints? Was it driven till the DS fell apart and beat itself against the truck and/or ground?? Could be a dozen different things, broken leaf, shot spring eye bushing or something allowing movement. Tire run out, drum run out/weight issue, axle runout, bent alxe, etc. Just throwing it out there, Tire guys are not going to know about a possible issue if nothing is brought to their attention, you end up balanced as "best as possible" They're not looking for anything else.