I have a 99 Nissan Altima and I put a new axel in on the passenger side and now when I drive 50-60 mph the car shakes. Y is it doing that?
Double check your work. Are you sure the axle slid all the way in and that everything was reinstalled and tightened correctly?
Does it have anything to do with the 2 bolts that hold the shock? And it doesn't shake when I go slow only fast on the highway
Oh yes. Are you talking about the two that are on the bottom of the shock assembly? One right above the other one? If so. Did you mark them before removal so you could put them back the exact same way they came out? One is cambered and if turned differently than it was when you removed them your alignment will be off.