Thoughts on a driveline wobble

[cjkirby55]

88 Suburban 1/2 ton 2wd. It has a pretty serious wobble. It's not a vibration but an actual, makes the truck rock wobble. My first thought is carrier bearing. It doesn't happen all the time but it occurs under acceleration and while maintaining speed but worse while accelerating. I climbed under it and I'm able to move the drive shaft in the bearing by hand a very little bit. It still has the plastic holding the u-joints so it's likely still factory parts. Any input is appreciated.

 

[bucket]

If the truck itself is wobbling, it sounds like a separated rear tire.

 

[cjkirby55]

That's a possibility, it's still running the wheels and tires it had when I bought it and I've had to plug one a while back. It's an intermittent issue so I was leaning away from a bad tire but swapping from my other truck for a day or two would help narrow it down.

 

[bucket]

I know they are usually a constant wobble, but not always. I had one tire that would cause an intermittent CRAZY wobble, even after removing the tire from the rim, I never could actually see anything wrong with it. Most others end up with a good visible lump in the tread.

 

[cjkirby55]

I've had some lumpy dry rotted tires, some that have had broken cords inside and some that were flat-spotted from sitting. Sometimes they're obviously bad and other times you don't know until they start flinging tread.

 

[89Suburban]

Just a word of advice on the center bearing. Slop in the rubber bushing is normal. I would not replace it unless the bearing itself has play or all of the fingers of the rubber bushing mold rip off.

 

[cjkirby55]

Everything looks right underneath it and movement in the bearing is pretty minimal. I had the truck out a week ago and accelerated hard pulling into traffic and it felt like the rear end was coming out from under it. No funny noises but felt all wrong. Maybe it's a trans mount or something like that going bad. Hopefully I can get under it tomorrow and really spend some time looking it over. It's not my DD and it's parked for the winter unless I need to tow or haul something big.

 

[cjkirby55]

Well bucket you were correct. Both back tires are coming apart. Looks like she's going to need new shoes.

 

[cjkirby55]

The damage...

 

[bucket]

They must be fairly old, I haven't seen a set of those in a while.

 

[cjkirby55]

The Daytona's were on my truck and I bought them new in 04. The Burb came with Mastercraft Avenger GT's. No idea how old they are but they aren't long for this world. I think this is the solution.