Should drive shaft(s) be balanced after u-joint replacements?

 

You should not have to rebalance a driveshaft if you are just changing u joints.

 

I know someone with an axle shop and they balance drive shafts he told me most people dont know they need it until its way off I dont know what the hell he was talking about but thats the answer I got when I asked him how you know when you need it done. So I would look for nicks dents or anything that might throw off the balance