Greasing my Shaft

For the engineering minded, there is a legitimate reason to NOT use moly in a roller bearing (like a universal joint):

Moly permits excellent sliding lubrication (like in a plain bearing/bushing or the prop shaft into the transmission), but too much sliding lubrication in a roller bearing can cause the rollers to not roll.
With enough time and wear, this can cause flat spots on the rollers and failure of the joint.

Is this likely to happen? Probably not unless the circumstances are very extreme.

The other aspect is that commercially available greases that are Moly fortified (example would be Valvoline Ford/Lincoln/Mercury grease which has I think <= 3% moly) typically don't have enough moly to cause issues.

That being said, if you want to go by the book, stick with a non-moly NGLI #2 grease for universal joints (Mobil1 Red, Mystik JT6, etc), and reserve the moly stuff for your prop shaft sliding portion.

 

Mobil 1 red makes it easier to know when the old grease is expelled.