What's the BEST driveshaft slip joint GREASE?

Right now I am using Ford Motorcraft XG8 blue Teflon grease. I was told it was the best...yes it gets rid of my thump, but I have to re grease every oil change. Grease seems to last aprx 3,200 miles before it starts to bind again.

 

I prefer a marine grease.

I know the zerk fitting is the easy method but feel every other time you still would need to pull out the shaft and spray it down with brake cleaner and then apply new grease to a clean surface.

Tranny fluid is a detergent and washes away the grease slowly.

Mine has last way over 3K since I have grease mine, probably at 8-10K.

Adding new grease to older grease that is breaking down is not a good idea.