So, here's the U-joint I took out. Well, I beat the hell out of it because it was rusted in place. Most difficult Ujoint. Ever. Turned a fixit project that should have taken an afternoon and turned it into a week+ ordeal.
Wound up beating the crap out of the yokes in the process. Had to dremel the lumps down and smooth it back out in the bores so the new one could fit. No sweat. I have a dremel and stones.
Got a moog u-joint. Heavy duty, blahblah, joint. Hit it a couple of times to drive it in and it broke- cracked a cap. Looked around at what was best, not was available and made some silly claim about being tough. Get the Spicer, say all the Jeepers that have 44's in the front. Okay, says I.
I wasn't sure what the materials and engineering difference was, but I wasn't buying another Moog joint. So, two days later it showed up.
Here's a comparo.
I'm not here to crap on Moog. They make pretty good chassis parts. I buy their ball joints and stuff, instead of the cheap garbage that Advance and Autozone and other folks sell.
I'm just reporting what I've seen in this comparison and why I went with the spicer 371 joint, in case anyone reading along is wondering.
1. The Spicer has larger diameter needle bearings. That generally implies a slower bearing speed than a smaller bearing diameter.
2. The Spicer caps have to be 2 or 3 x as strong. I didn't field test them, but I did whack them a couple of times and noticed less drift tracks in them for the same hits.
3. Greases are different. Moog uses the blue stuff. Spicer uses the red. What's the difference you say? The blue stuff is lower temp and won't last as long. Google it, if you're curious. There are entire engineering papers written on it.
The spicer I took out was rusted and beat to pieces. But the internal part, the cross, was still in one piece with no obvious stress indicators, so I could have, if the bearings had fallen out on a trail, probably kept chugging and gotten out of a muddy spot very gingerly with it. I'm not saying anything. I'm just saying.