If it's the driveshaft, take it out, mark it, and separate it at the slip
yoke. Grease the splines heavily, and put it back together, using new clamps
on the rubber boot.
Be sure to mark it before taking it apart, in order to line the splines up
the same way.
You can also drill and tap and install a zerk fitting in the outer part of
the shaft.

Good luck,

Spdloader