2000 Toyota 4Runner torques on acceleration and deceleration.... most noticeable when above 50mph... torques to the right when accel, to the left when letting off the pedal.... replaced upper and lower ball joints figuring that might be the issue at 160k miles on truck.... didn't help. all suspension parts appear in good shape... it feels like an axle issue? it's a limited slip diff and it has been making some pinion gear whirl in the past.... I have used the truck to pull a 3500lb boat a few times over the last few summers.... ideas?