I recently pulled the driveshaft off my 1986 Dodge B250 van, expecting to replace one or both universal joints. I was surprised to see they both have zerks, so can be serviced (sure wish I'd noticed sooner).
The rear U-joint moves freely in all directions and seems fine, the front joint only moves freely in one direction, the other axis has definite resistance, but can still be moved by hand.
There is no play or looseness, just stiffness on one axis.
My general understanding is that if a U-joint is showing signs of wear, like not moving freely, it should be replaced. However, if I grease this joint and it begins to move freely, is it considered it still good?