99 blazer 2 door vibration

[rjk6138]

o.k. it only happens at 65mph or more. at least thats when i can feel it. tires rotated and balanced already. drive shaft just had joints. thinking maybe shaft balance? Anyone heard of a out of round rotor causing a vibration? it's rear disc. any thought?

[Sparky2263]

Sounds like the U-joint install didn't go so good. I'd be taking a good look there, and soon.

[jbayless]

I have this issue in my 2001 Blazer 2D 2WD as well (just purchased two weeks ago with 18,000 miles on it). The dealer showed me a TSB that indicated it was "normal" operation and that no service is required.

My Blazer vibrates badly between 65 and 75, and the vibration is worse in hotter weather (70+ degrees outside). I too have replaced the tires, balanced them, had the driveshaft checked and the front end aligned. It is strictly a matter of shoddy workmanship by GM on some of these trucks.

I found this old thread in the forums here, which also has a copy of the TSB #PI01273B that the dealer showed me.

http://www.s10planet.com/forum/archive/index.php/t-1608.html

[j894]

Doesn't seem right. My 01 4x4 seems rock solid & no vibrations at 90mph. Until you have to make quick maneuvers.

What kinda of vibration? does the truck shake? there a vibration or something that slowly gets worse as you speed up? or only 65-75?

Drive shaft balanced & u joint Ok?

[Hammer Head]

Is it only in Blazers? Maybe it has to do w/ the way the Blazer is mounted to the frame.. I know it's mounted differently than the truck.

[jbayless]

It happens off and on at all speeds above 65, but seems to be worst around 65-70. It does not shake as badly when it is cold outside.

The U-joint seems to be okay ... I am taking it into the shop to have it checked out next week. I'm going to have the driveshaft balanced too.

That thread I linked in my first post in this thread is exactly what is happening to my truck, right down to the dealer response. Seems lame that GM would make something screwed up and then choose not to fix it. This is way more than just a rough ride -- I expect that in a truck. Repetitive vibrations are very annoying.

I've already dropped $350 on new tires trying to solve this, as well as an alignment. I've got to talk my wife into the driveshaft balancing now. :-)

Here is that TSB the dealer waved at me. It also applies to S10 trucks.
__________________________________________________ _______
Vibration at Highway Speeds- suspension wheel
#PI01273B - (Sep 15, 2003)

Vibration at Highway Speeds

When servicing the vehicle with the VIN you entered, the following diagnosis might be helpful if the vehicle exhibits the described symptoms.

Condition/Concern:

Vibration that can be felt in seat of pants or a body shake at highway speeds.

Recommendation/Instructions:

This condition may occur when the vehicles EVA readings show the tires at 12-14 Hz, or 60 mph, and 0.07 Gs. This condition may be induced or increase in intensity on rough roads. This vibration is NOT torque sensitive and CANNOT be felt in the steering wheel/column.

This vibration is considered a normal characteristic for these vehicles and no repair attempts should be made.

Please follow the diagnosis procedure thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance. This diagnostic approach was developed for the VIN you entered and should not be automatically used for other vehicles with similar symptoms.

Models:

(00,01,02,03 Chevrolet Blazer 2WD/4WD) and (00,01 GMC Jimmy 2WD/4WD, U.S only) and (00,01,02,03 GMC Jimmy 2WD/4WD, Canada only) and (00,01 GMC Envoy), and (00,01 Oldsmobile Bravada AWD) and (00,01,02,03 Chevrolet S-10 2WD/4WD)

[jbayless]

FYI - after three visits to Discount Tire and the dealer failed to resolve my vibration issue, I took the Blazer to a shop that balances the wheels while they are on the vehicle and trues the tires (Southwest Brake and Alignment in San Antonio). The vibration is now gone.

[20Xtreme02]

That points to the fact that the problem isn't the wheels or the tires. They were balanced to compensate for a problem with the vehicle. Although you may be fine to run things the way they are now, without the vibration, the root of the problem is still there. It will resurface next time you rotate your tires or buy new ones.

[jbayless]

Yep, I can expect to have some expensive tire rotations and balancings in the future. I am considering new wheels to see if that resolves it ... I know now that two of my rims are a bit warped.

[Hammer Head]

How new are your brakes? Maybe a rotor is out of round. Has the car ever been in an accident? Maybe a spindle or axle is a little bent. Those are two things off the top of my head I'd be lookin at.

[jbayless]

Brakes are fine. The truck has a clean accident history, and has only 19,000 miles on it. The same owner had it for the whole 5 years. My mechanic said there is no sign of seals leaking like he would expect with a bent axle. He took off all the wheels and examined the brakes and rotors, and checked the bearings.

I do not know the root cause of the vibration referenced in the Chevrolet TSB I linked above. If that is what's wrong with my truck, it's something that GM deemed did not merit fixing (probably a cost vs. benefit issue).

After this balancing, I have a large weight (about 3.5-inches long) on the back left wheel, and another fairly sizable one on the front right wheel. Both of them have more weight than they did from the Discount Tire "ride matching" balance. The other wheels are about the same as before.