My new u-Joint has a grease fitting on it. Should I grease it as soon as I put it on?

 

Yes. They only put enough grease in them to hold the needle bearings in place. You will have to pump quite a bit in there the first time. If the zerk fitting is at an angle, make sure you put it so it faces the front of the truck!! If you don't, you won't be able to grease it later when it's installed unless you drop the shaft from the rear end..... Guess how I know that!

P.S. On the front U joint, you would want the angled zerk to point to the rear....

Mitch