Did you remove the driveshaft when checking the joints?
If the pinion is loose, the gears have been meshing improperly.
Moderate chance you'll NEVER get those gears quiet again because the wear pattern has been disrupted.
OTOH, it doesn't really hurt to try.
Not having high hopes is a good idea.
Yes, I removed the driveshaft making sure to mark it‘s orientation. The u-joints held their position (no flop) and moved smoothly. Caps were filled with grease and everything moved smoothly.
After I tightened the nut, I also marked the nut and pinion with a paint pen so I could see if it loosens back up.
i took the chance last night and drove it to the store which was about 10 miles round trip. I didn’t hear anything but tire noise. When I got back, I checked and the nut hadn’t moved.
I'm not putting much faith in it long term. I’ve ran into enough problems with this truck because of things the previous owner did (or didn’t do). I strongly feel that a similar circumstance happened on the front differential and that’s what caused it to grenade itself. The 35” tires that were on the truck were so loud they covered any other noises.
