Hello. I have a 2001 LE Pathfinder, 2WD.
At appoximately 40 mph, it begins to shake side to side pretty violently. It usually happens when the wheel is turned to change lanes.. It is like a couple of large guys inside shaking side to side. As soon as I let off gas, it settles back down.
I can activate this by traveling down the road and quickly jerking the steering wheel side to side a couple of times. Then the body of the truck rolls side to side. During this, the steering wheel is straight and there is no vibration in the steering wheel itself.
Everything mechaincally seems good. Tires are good, have been re-balanced recently, but did not solve the issue. I had a mechanic look at it and he said that it looked good (He could not get it to roll like I described). It used to do this at 65 MPH, but now is doing it at a slower speed..