1980 pontiac grand prix vibration felt through driver seat?

i have a 1980 grand prix i feel vibration through my driver seat that start around 45 -50 mph it feel like it begin at the rear and rolls all the up to the front i changed the rear u joint the front was in good condition,front wheel bearing(inspection revealed defective)checked the rear components they all seem in good shape.its a pulsating vibration. any ideas?
1980 pontiac grand prix vibration felt through driver seat?
The answers above are good. Another possibility is a broken steel belt in one of your tires. That will make your tire out-of-round and cause vibration.
1980 pontiac grand prix vibration felt through driver seat?
sounds like wheel balance
It could be:



Brakes malfunction

Wheel alignment/balancing

CV joint gone bad



Check out those things. On a car that old, things are going to start to deteriorate. My guess would be the wheel alignment as the primary culprit.
did you check the transmission mount?

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