Symptoms:

In the last couple of months, my 99 Silverado Truck vibrates between 65-70 mph. When this happens, the truck shakes violently and you can feel it also on the seats but not on the steering wheel. I rule out the tires because it has been aligned, rotated and finally replaced. I have been to 2 other alignment shop and they cannot find anything wrong with the suspension.

I am getting scared driving this vehicle and this is my only work vehicle, can you help?

Tire Problem Advisor:

Some GM tires installed on these trucks have too much radial run outs. To fix this problem, GM put out a service bulletin replacing them with special set of tires. Since you replaced the tires already, it’s now too late to ask for warranty. However, you can still do this: ask your tire installer to find the same kind of truck but has no vibration problem and try the tires in your truck.

If the problem goes away, it means the new tires installed are not the ones GM recommends. The service bulletin is supposed to start on models made in 1996 onwards. You can also contact any GM dealership nearest you.

Notes:

When in doubt, bring your vehicle to authorized GM dealer shop for a second opinion.

Above repair is only a recommendation and you do this at your own risk. Always have your vehicle align after replacing the tires to prevent repetition of the problem.