I just replaced the rear end on my 1997 F150 2WD. While it was apart I replaced the u-joints on the rear driveshaft. Afterwards I heard that I should have indexed the driveshaft as the whole thing is supposed balanced as an assembly. Is this true? Do I have to get it balanced again somehow?

 

I've never run in to a situation, that by changing u-joints, something became imbalanced. I do however, mark everything with chalk, to at least assemble the parts in some sort of order. You have only 2 choices with joints/yokes, 180 deg. apart. I'd think by now any imbalance would be pretty obvious.

I've only had a few shafts balanced, but those were custom made.

Dave

 

just make sure your front and rear ujoints are lined up and all should be good

 

You could inspect the shaft for weights, they are welded on where needed in the manufacturing and balancing process when the shaft was made. Over time, they may come off through corrosion. If that shaft was out of balance it would manifest itself as a vibration at different speeds. Make sure you have the proper endplay in the u-joints before installing the whole shaft back in the vehicle. They must pivot freely without binding!

 

Try and keep everything lined up is a good rule, may have to rotate the d.s. is all. There used to be an old school trick, a big hose clamp installed on the driveshaft; can be rotated in thirds or whatever to isolate imbalance or somesuch, anybody remember this?? Anyway keeping vibration levels low as possible is important for bearing life and other components.