After installing 17 inch rims on a 1998 Pontiac Grand Prix why would the car start shaking at 70mph but stop at 80?

Answer 1

Rims are out of balance

I have the same problem with my 98 prix gt, but its the stock 16 inch mags.. at around 70km/h it begins to shake every 10-15 seconds.. when i speed up to 76km/h it stops..

Actually, this can be caused another way. If the center of the new wheel is larger than the diameter of the center of the hub it can cause this vibration. What you could do is go to a wheel shop and get a set of hubcentric rings. All they are are small plastic rings that fit into the center of the after market wheel and center it onto the hub. You will need the make/model of your car as well as the make/model of the new wheels to get the correct size.

ummm no...rims not balanced possible...if center caps make your vehicle shake at speeds people travel everyday those rims need to b recalled..wheel wobbles and vibrations are affiliated with many parts on the front suspension...things to examine...which side tires or both...check wheel bearings...tie rod...sway bay and end links...axels...alignment...steering rack and pinion assembly ( expensive repair )...ive had the same issue with my 1999 gtp...ended up being my wheel bearing...one little issue can cause many ive went through 5 wheel bearing because of missed repairs...alignments off or broken parts CAN and WILL wear and break other parts before you know it.

1aauto.com has a good cheap selection of OEM replacements for vehicles and free shipping..i got my bearings sway bar tie rod and much more from here..hope this has helped with your problem