Why am i getting a vibration at 75+ mph but not in steering wheel?

Question

It is a 2002 chevy malibu 192,246 So far I have replace both tie rods ends Wheel bearings front In the rear I have Replaced both wheel cylinders

Tires honestly My front ones are slightly smaller than the rear Everyone says they are feathering I just had new shocks and struts done over a month ago and someone said it would reverse itself overtime. Brakes are fine. Though was told a brake shoe in the rear was starting to crack. I had an alignment done as told and balancing was right on. I dont know if I just should replace all 4 tires with brand new same size tires What to do please help

Answer 1

High speed vibration on a FWD vehicle could be wheel bearings, but you've already replaced those. Mostly likely is bad wheels and/or tires. Out of balance, uneven road force, or a bent wheel could all cause high speed vibrations. Uneven road force means that the tire doesn't exert the same amount of pressure at all points around the tire (imagine if a section of the tire was stiffer than the rest). This would obviously cause vibration as the tire rotated, even if it was balanced.

Most tire shops should have a road force balancing machine that will be able to rule out balance and road force at the same time. I believe these machines will also detect a bent wheel.

If you want to test more before $pending, try moving the tires around (front to back) and see if the vibration moves with it.

Answer 2

Was having similar issue & noticed my left front tire had a bump. Got it replaced and it’s fine now. But try and use manufacturer recommended tires and rim.