Tires: Truck bouncing/shaking/vibrating, hunter gsp9700, chevy colorado

Question
I have a 2004 Chevy Colorado and just purchased 2 tires to replace the worn rear tires. The garage moved the 2 good tires from the front of the truck to the rear and put the new tires on the front. Now I am experiencing a bouncing in the truck at all speeds. What could be causing this bouncing?

Answer
If you are experiencing the bouncing in the seat, then it is probably irregular wear from the front tires.  This is caused by misalignment and aggravated by insufficient inflation pressure and insufficient tire rotation.  This can be corrected by either replacing the tires or waitung until a new wear pattern is worn into the tires - which might take some time - or it might never be completely eliminated.

But if the "bouncing" is in the steering wheel only, then it is probably the new tires and they are probably out of round, which can not be corrected by balancing.  To confirm this, a Hunter GSP9700 machnine has to be found.  This machine will also help confirm if the rear tires are the suspects.

Try finding one at:

www.gsp9700.com

BTW, it is better to put new tires on the rear to prevent vehicles from losing grip in the rear first - a more troublesome condition than losing grip in the front first.  I suspect the tire shop put the old tires on the rear since they had some wear left, and were hoping the irregular wear might correct itself.