Since I had my axles out, I decided to change my 38 yr old wheel bearings and seals. Some people think that the diff lube greases the bearings. Wrong; they use wheel bearing grease just like the fronts. I DO NOT USE GREEN BEARINGS. They use ball bearings and don't have the contact area for side loading like the factory tapered-seat, roller bearings. Too many stories of those going bad after a few years. Those are for drag racing only.
Here are a couple of pics on how it came apart and what you need to buy to get this done. The inner seal keeps the diff lube out of your wheel bearing. The outer seal keeps you wheel bearing grease out of your brakes or brake dust out of your bearings. The metal gasket seals the brake backing plate to the housing. The foam gasket also helps to keep any wheel bearing grease out of your brakes and goes between the bearing retainer and backing plate . I got my metal gasket and foam gasket from Fel-Pro.
Collar has to be split to release it’s hold on the axle.
I split it with a cutoff wheel on an electric grinder then shoved a chisel right into the cut. I fell right off.
You could now use a press to pull the bearing off, but I don’t have one so, I then cut the top of the roller bearing cage and pulled out all of the bearings so I could split the inner race after cutting off the outer race and bearing cage. Try not to nick the axle while cutting any parts off.
I took the axle to a friend's press and used the old split collar to press on the new collar. Use anything to lube the axle before pressing the bearing and collar. WD-40 works, but I used what was close by, tranny fluid. One pic shows a grease needle that I picked up at a tool guy’s tent at a swap meet. I then noticed that my All-Pro Auto Parts had one on their wall. It sure beats the messy hand packing or bearing packing tool that I used to use. It gets the grease right into the bearing.
When installing the axles, put the LEFT (drvr's side) non adjustable one in first and tighten it down. Back out your bearing adjuster on the right axle and tighten down the 4 of the 5 axle/ bearing retainer bolts. Leave the one off that holds the adjuster lock plate. Your adjuster should be able to turn with the other 4 bolts tight. If not, find out why it doesn't turn. I then tighten down the adjuster while turning the axles to sqeeze out the grease, then back it out a little till I hear a little end play by using the push-pull method on the axle. Then tighten it down leaving a couple thousands for expansion, then put the lockdown plate on. You must leave a little play in there for thermal expansion or you will burn out the bearings. If you can't tighten down the end play, you might be missing the center block or pins in your posi. Look into the housing to see if anything is missing. Some of those pins used to fall into your gear lube when you pulled the axle. If you are changing over from green bearings, you may be missing the pins. The older style sure-grip, common to 742 center sections used these. Open and cone-style didn't use them. So if you now have the clutch style posi in any center section, look for these pins. You should not be able to look all the way through to the other side. Pins are now availabe repro. I see them on Ebay.
Total time including driving to use my friends’s press was about 1-1/2 hours.
Rob
Edit: My pics were gone so they are now hosted on photobucket.
