I have a 2001 dodge ram 1500 with bad U joint on drivers side front axle. how do i know if i need to replace the axle spindles.

any help thanks,

 

Welcome to the site. I will move this thread to the second generation Ram section,
FF

 

If you break one while changing the u-joint, or, there are obvious signs of bearing munching going on. They don't usually need to be replaced, just changing out the u-joint should be adequate to the task.

While you are in there though..... Might consider doing the ball joints, possibly the axle seal on that side, and the hub/bearing assembly if it is going bad.

 

Be careful to pull the axle shaft straight out (support it between the steering knuckle and the end of the axle tube) and don't let it drag on the seal inside the axle tube or there's a good chance that you'll start leaking like I did after changing a u joint.
Use plenty of anti-seize and if you decide not to do the ball joints then it'll be easy to replace them later.

The axle spindles (knuckles) should be fine unless you jump it often, have massive tires or have really worn out ball joints.