Try to figure this one out. Wife's truck, 98' Sonoma SLS, 4.3L/4L60e,
3.42's, 34K miles, I hardly ever drive it. Stock 16x8 aluminum wheels,
Firestone Firehawk SS20's with less than 10K on them.
Wheels are perfectly balanced, vehicle is aligned, all front end components
are tight, suspension components all check out.
The truck rides as it should EXCEPT when you're driving on newer asphalt and
only between 60-65mph. On a freshly paved, smooth road it feels like both
rear wheels are out of balance. Can't feel it in the wheel so much as you
can feel it thru the seat in the lumbar area. On an average road it rides
It's weird as hell, you can be driving on an older section of road,
everything is fine, then you hit a construction zone with new roads and it
feels like your inside a paint can on the mixer! End construction zone,
back to older road, everything is back to normal. If I get it up to
anything above 70mph the shimmy is gone.
Anyone have a similar experience? What was the culprit?