Having trouble with my 98 Dodge Ram Truck?

[Negeshia]

I have a 98 dodge ram 1500 that was hit along the drivers side. I replaced the springs and drove the car for a year. The mechanic said the drive shaft was damaged and so I bought a used one and had it replaced they also put in new universal joints. Now when I start to drive it, if I take off a little too fast (not ever time maybe every tenth time) it feels like the back tires are running over rocks and the back end bounces. If I back off on the gas it corrects itself and drives fine. Now it seems it has happened at speed once. I took it to the mechanic and he said he didn't know what the problem was but he called someone who thought it was the transmission. What do you think?

 

[yankeegray_99]

axle bearings particularly drivers side if the tire was hit.what seems to have happened is the bearings were damaged from the impact,and occasionaly they wont spin correctly in their carriers.backing off on them allows them to reseat themselves and smooths out.the bouncing is most likely from the bearings actually binding a new set of bearings shouldnt be that much,and while at the shop have them check out the rest of the axle for any cracks,or bending etc.