I've looked up there a few times. Putting grease on the u-joint end of the
drive shaft is probably good-enough maintenance. Unless you're somehow
getting a bunch of water up in there, the u-joint connection to the output
shaft is probably good. When you do end up going up in there, pulling the
boot off the u-joint and stuff, bring your curse-word dictionary with you
for when you're putting the boot back on

-Mike