After recently getting cheap WalMart tires I have a severe shake in the vehicle around 65-70 mph. Tire/wheels are balanced, alignment caster, camber, toe all 4 corners are in spec, struts don't appear to be leaking/oily, bounce test at all 4 corners works the way I've been told it should.
Today, VibrationControlSystems
Symptons are driving steady state at 65 mph vibration bad; lift throttle, vibration subsides greatly; get back on throttle hard, vibration extremely severe; going up incline, do the lift throttle, back on throttle and vibration feels like the car is coming apart. Note that the vibration starts at about 35-40 mph and behaves the same, just with less "amplitude" than at the 65-79 mph range.
Does everyone concur that mounts are the place to start with this? He also said a couple of the tires are visibly out of round, but to start with replacing the mounts.
Next question, can one tell if 1 or more mounts are bad by watching the engine when putting the vehicle in drive or reverse (with brakes applied of course)? Is there a maximimum amount of movement that the engine will go thru when putting the vehicle in gear? I've heard people say the engine should never move when putting in gear, but that doesn't sound right to me -- there has to be some play in the mounts right? You can't go from no torque to torque with out some movement in the mounts and hence the engine right?
How about in drive, brakes firmly applied, then more throttle? Should you see any movement from the engine with throttle?
Any other methods for testing engine/tranmission mounts (besides obvious visible damage)?