This has happened twice so far. Upon hard acceleration, I can feel the rear end "bucking." I'm not sure if that is an accurate description of how it feels... but it does resemble someone trying to learn stick and the car bucks, though this isn't as aggressive as that. It's subtle, the rear axel seems to buck until highway speeds. Could it be the Diff? I don't think it's the suspension....
Ideas? Is it something that could potentially be serious?
Dough