First Post .... Help on a vibration

[DuallyDave]

Hello All !
I have a 96 C2500 Suburban 7.4
There a a rumble/vibration and it is speed related.
at 45mph start to notice. At 55mph very noticeable.
New tires and i just had them rotated and balanced. No change
New tranny mount, new u-joints,
even had the driveshaft rebalanced.
Thought maybe a bad rim or tire. So I put the spare on every corner and no difference.

Has anyone else have this issue?

Thanks
Dave

 

[volunteerff21]

When was the last time you had it aligned? Worn out steering components such as tie rods can cause vibrations too.

 

[DuallyDave]

Just had new tires with alignment 3 months ago. just had the tires rotated and balanced 2 weeks ago. New u joints. Drive shaft rebalanced.
I now noticed that the front right rotor id a little warped. but i have never seen one cause a rumble thru the floor.

 

[skylark]

I would be looking really close at the carrier bearing.

 

[98_k1500]

Does it change if you coast/apply throttle?

 

[great white]

your description is consistent with a U joint going away.

If you are confident they are installed correctly (IE: now tipped roller bearings, etc) next suspect would be carrier bearing (if you have one) as Skylark mentions. Next thing to look at would be the slip yoke for excessive play.

Could be a warped brake disc, I've seen weirder things...

 

[DuallyDave]

One piece driveshaft. Its aluminum and use to be wrapped in carbin fiber. But carbon fiber has rotted off. Thats why I had it balanced. It has made this issue since I bought it in November 2013. So installig new ujoints didn't change a thing. So im pretty sure they are correct. I took my spare and put it every corner thinking it may be a bad tire.
It doesn't change with throttle or brakes.
but does increase and decrease with speed..

 

[98_k1500]

I would rule out the rear end bearings as they would change as you apply throttle/coast. Bent rear axle shaft maybe? Rear hub bearings if you have a FF axle? That would be the direction i would go if i was having this problem.

 

[thz71]

One piece driveshaft. Its aluminum and use to be wrapped in carbin fiber. But carbon fiber has rotted off. Thats why I had it balanced. It has made this issue since I bought it in November 2013. So installig new ujoints didn't change a thing. So im pretty sure they are correct. I took my spare and put it every corner thinking it may be a bad tire.
It doesn't change with throttle or brakes.
but does increase and decrease with speed..

It's not carbon fiber and carbon fiber doesn't rot

 

[98_k1500]

Im not sure what that composite shaft cover is made of, but i know i have seen more than one of them "rotted" and slung off.