If they're greasable, grease them and see how it goes. If they're not then replace them. Also if you have one check the centre bearing on the rear drive shaft.

 

You need to have them replaced if it's your u-joints. You can't grease them if they're the factory ones. They don't have a zerk fitting. I'm not sure if the aftermarket regular stores (pep boys, autozone, advance auto) have them with zerk fittings.

 

Generaly they keep the greaseables in stock, if not they will order them for you. I never fit the stock ones as you can't grease them and always try and get heavy duty ones. That's my opinion anyway.

 

Cool, if you install them yourself just some advice. Make sure you install the u joint so the zerk fitting is under compression. Otherwise the torque of the motor will pull it apart at the fitting since it would be the weakest part of the joint.

NOTE: For maximum u-joint strength, you want the zerk fitting to be under compression when the driveshaft is turning to drive the vehicle forward. In the case of this driveshaft, this shaft will rotate clockwise as viewed from the end and the driveshaft yoke will be pushing against the zerk section of the cross.

 

That's why I got some with a flush fitting on the end of the bearing when I did mine! Actually it was a total fluke. I didn't know some came like that until I opened the box. Seems like a good idea to me. I got mine from NAPA

 

Very nice stunt!!!! I didn't know they came like that either!!!! Never seen that, you got pics?

 

Niether did I until I got these! I would love to post a pic but I am not going out into the freezing snow to take one! :-)

 

Can you see the shiny thing in the middle of the bearing? That's the flush grease fitting. Yes I know my diff leaks!