Need help diagnosing a vibration issue around the speeds of 40-55 mph. Taken it to two different shops and still not resolved. The sound is similar to if you were next to someone with a loud radio with the subwoofer etc. It is on a 99 tahoe with one size larger tires (285s) with allow rims. I had the tires and rims before this started though. It started not so bad at first about two years ago but has progressively gotten worse. Things I have tried so far include: tune up, tire rotation and balance, rebuilt transfer case, front pax cv axle (was told the other side is ok), removed driveshaft and checked U joints (they seemed ok), had driveshaft balanced.

One shop said it could not be duplicated on lift. The only thing I am noticing is there is a little play in the front shaft where it goes into the transfer case but I am not sure if that is normal or not.

Thanks for any suggestions or help.

 

If I understand your thread, this issue has only been with these wheels (rims and tires) and not with any others? If so, I'm thinking tires.
If they're worn and nearing time for replacement I'd start there. If they still have a lot of tread and you're not looking to replace em just yet, do you know anyone with wheels that would swap on for a comparison test drive to rule out your current wheel/tire combo?

Any tire pros know if tires with pulled/damages cords will show up on a balance machine? With no weight on them my guess is no...

 

Do you let your truck sit for long periods of time? I agree with noj, you are listing some good reasons to be suspicious of your tires/rims. I would borrow a set of wheels from someone and see what it does.
If your driveshaft is not straight or one of the yokes is messed up, you will get exactly what you are describing, but I think it should show up on a lift. Still, if it is not the wheels/tires, get the drive shaft looked at more carefully.

 

Check to see if the tires are out of round. This happens to tires that sit a lot in one position without moving. They develop flat spots. You said you had the tires balanced. Were they hard to balance?

 

Thanks for the replys, I do have access to my original stock rims and tires. Nothing I would want on the truck for an extended time but probably enough to decide if in fact the tires are the issue. I put air in the tires to see if it holds and will put them on in the next few days.

The tahoe is pretty much a back and forth to work vehicle. It may sit but not much more than a day or so. I will keep you posted.

 

I put the original stock rims and tires on the tahoe and drove it for several days. It still has the same vibration issue pretty much just above 40 mph to a tee. Dont know what else to try next? I may replace U joints next although they did not seem bad when taking off the driveshaft.

 

Get the drive shaft/yokes looked at more closely.

 

I also have same problem with my 99 tahoe. im clueless on what it is.