I've still got to say that I believe needle bearings are better suited to open driveline U-joints that have trunions with a grease fitting that lets you drive lube from a grease gun into the joint from the inside under pressure. In my experience with my '46 4 speed crashbox and an enclosed driveline, very little lube comes out of the back of the trans to lube the U-joint. And yes, this is with the transmission properly filled. It's also going from the outside of the joint to the inside, which is not as good as the greasegun method. As a consequence you get premature U-joint failure. This is with either needle bearing type or bushing type (although the bushings seem to hold up a bit better).
After replacing several of these U-joints (getting really hard to find), I decided about 15 years ago to start periodically lubing the U-joint through the pipe tap that's right above it on the rear of the trans housing. I put in about 4 oz. gear lube every 300 miles or so. Interestingly, I find that my trans will become overfull from doing this, indicating that the lube is going from the U-joint back into the trans somehow. This takes a while, so that I'm usually draining a bit from the trans when I add to the U-joint housing. Been doing it for years and hasn't hurt anything, though. I notice that when it needs some lube, the truck seems to develop a little noise and the U-joint tends to vibrate a little - lube it and it's fine for another 300 miles.
Does anybody make a trunion that fits these enclosed drivelines that has a grease fitting on it?
Last edited by David Bush; 01/22/2016 11:15 PM.
