Front differential pinion bearing replacement

[ep7360]

I have a vibration coming from the front differential pinion while driving since I’ve owned my 1969 88 (16 years). Just rebuilt the engine and transmission and started driving after many years of sitting in the garage. I ended up removing the front driveshaft after I realized the problem, which stopped the vibration but I have no 4WD. I Bought a rebuild kit recently to replace what I believe is the issue (pinion bearing). So, I have a potentially stupid Question: do I need to fully remove the differential from the axle housing to replace the bearing or can this be done installed in the vehicle?

[roverp480]

The pinion has two bearings, and you need the differential out of the axle to work on it as the inner bearing is only accessible from the inside. Is the existing pinion actually loose or notchy , as I have usually found wear in the universal joints is a more common reason for vibration. ? The picture shows the two bearings. This is the early version with the oil seal in a separate end cap, later ones have the seal directly in the iron diff. housing .
14142

[ep7360]

I had hoped to not have to disassemble the front end again. Just finished replacing the swivels and have the engine reinstalled after the rebuild…😫. It’s definitely the pinion causing the vibration. It seems to have quite a bit of wobble at the flange with the driveshaft removed… Thank you for the diagram and input.

[charles1943]

You COULD have a loose [castellated] nut on the input flange & it's a 20-40 minute job to drop the diff-end of your prop shaft and see if that nut is loose. This would have happened due to bearing wear [not all of which is necessarily bad]. I like to "do the forensics" and count the flats it has 2 B tightened, which will give yo the back story of "it was 3 flats loose and tightening that nut made the vibration quit" kind of thing. DO NOT NOT NOT over-tighten it!! The Rover dealership in Albuquerque did that to the rear diff on our '64 and it locked up 5 miles later. PRETTY EXCITING, that!!! "Medium snug" should do it.....

[charles1943]

! more thought Erik....R U sure your noise is actually coming from the diff? Noises can telecommunicate all around the truck is peculiar ways. I'm guessing U....got the truck in the air and put it in gear and felt (??) the vibration actually coming from the nose of your diff, correct? If U have the diff out it might B a good idea to replace all the bearings with new, high-quality ones.....NOT Chinese!!! You might also check the axle case for straightness.