Unique problem - 2001 s40 front shakes at around 30 mph and up but only upon acceleration. I can be going 60 mph with whole car shaking as soon as I let up on the gas the shaking stops. Have had a wheel alignment, tire balance, new tires, new shocks, sway bar. Dealer says its a wheel bearing and not motor mounts, yet I hear no whine or bearing sound on turning, etc. 3 different mechanics just scratch their heads and want to replace parts - bent axle, transmission, mounts, bent rim, etc. Any help out there!!