What series u joint are you using behind 800+ hp on surface drive apps? I have some series 1410's and I installed NAPA 330 joints and noticed I have some that the needles are "brinelled" into the cups and trunions. Spicer indicates it is typically caused by excessive torque. I have very little side or vertical angles going on and they are always getting grease. Thought possibly it's the quality of a NAPA joint? Anyone else have this problem with Merc joints? Glad I decided to pull them to inspect! They are on a short shaft between the trans and the extension box and would certainly make a mess if one let go!

lots of small needles are better than a few larger needles.