I have greasable u-joints. The problem with them is I can't get the grease gun on the zerk when the driveshaft is on the car. Maybe it's just the front u-joint. There's probably a different zerk or grease gun that will. So far I have pulled the driveshaft once to do the job.

 

You can buy a needle adapter to fit your grease gun that allow the tip to fit hard to access places. You just hold the end of the needle on the ball of the zerk. I think this pic was from Autozone so anyone should have them.

 

I can tell you without a doubt non greasable last longer. When I started as a fleet mechanic 35 years ago they were all greasable and were greased regularly on an aggressive maintainence schedule, and I replaced a LOT of u-joints. Years later we switched to non greasable and the u-joint life went up dramatically. One reason is the seals on the greaseable ones have to be able to allow grease to escape whereas the non greasable joints do not so they can have a tighter seal to keep them protected.

 

Damn, no kidding? I would've lost that bet.

 

Although probably not an issue for most of us, I understand that non-greasable are stronger due to being solid and not drilled for the grease passages. I guess it could be an issue for those who drag race...

 

I understand that non-greasable are stronger due to being solid and not drilled for the grease passages.

Mostly the Zerk fitting hole between the trunnions, and the other holes don't lose much strength. . +1 to the Zerk fitting in compression, as they can crack at the hole under high torque.

I use greasable in off-road vehicles, where purging any water is important. Don't ask me how it gets in there, but it does. Lifespan goes way up on those, but for most of us, solids are fine and in good brands a bit stronger.

And I use the hardened narrow pointed tip (not hypodermic type) for all of them now. It's easier than switching the tip back and forth, when I can find it , and I can lube other stuff with it.

Lincoln 5803 and LockNLube have worked well for me:

 

ball joints and tie rods the same. the book says to remove the plug at 36,000 miles and grease 2 pumps then replace the plug. repeat every 36,000 miles.

 

The non-greaseable u-joints are almost always stronger, not having holes drilled through them. I find that many greaseable u-joints suffer from the same problem as greaseable tie-rod ends..... When greased there should be enough "new" grease put in to flush out all the "old" and dirty grease which is then wiped away so that dirt and moisture doesn't collect on it. If the boot is 100% sealed that's a different story though.

 

Non-greaseable are stronger and were designed for drag racing.
A greaseable should always be installed with the grease fitting hole in compression as the shaft rotates. Draw yourself a diagram and think about it.

 

I purchased Duralast u-joints at AutoZone for my 68 Mustang 289 w/C4 auto. The rear u-joint fit perfectly. The front replacement (1-0153DL) had the correct bearing cap diameters (1-1/16") and correct width but the casting itself was bulkier and fatter than the original. I could easily slip the old one back in place but the new one was impossible to even get close due to the bulky casting. I just checked on here to see if anyone else has run across this. I'll be taking this one back and searching for an American-made replacement.