Rear Axle Installation

Tonight I finished re-installing the rear axle assemblies into the differential, a job I had begun yesterday. With the rear axle bearings replaced, pressed on, and packed with grease, it was just a matter of re-inserting them into the differential, lining everything up, and tightening the bolts.

First I had to replace the inner grease seals. Removing the old seals was more difficult than I’d anticipated. I bought new seals from Carl Jaeger, a roadster parts vendor located up in Canada. The seals are NLA from Nissan but Carl sold me a pair for $15. Here are pictures of the new seals and the old seal in place on one side.

I couldn’t get the old seals out and I tried a lot of methods. Grabbing with pliers resulted in tearing off bits of rubber. So tonight on my way home from work I stopped at Autozone to see if they may have a puller for rent that would do the trick. It would need to be small and have the arms gripping outward unlike a typical pulley puller. The provided me with the hooked seal puller shown below. For $7 I decided it was worth a try. I hooked it on the edge of the seal as shown on the packaging.

I gave the tool’s handle a couple of taps with the hammer, and out popped the seal! This is a tool I highly recommend for this purpose after struggling all day Sunday with how to remove those stubborn seals.

I wiped the area behind the old seal clean in preparation for the new seal.

I pressed the new seal into place with the flat side out, same as the old one. I found a 1 1/4″ socket that was about the same circumference as the seal. After adding a short extension to the socket I had a nice little driver to seat the seal in place.

So I lined the socket up over the seal and gave it a couple of light taps with the mallet. The seal seated firmly and squarely into the axle housing.

With the new inner grease seal in place, I inserted the axle. Pictured is the installation of the left axle, which had two shims and which I marked in order to be sure I kept track of it. The right side required no shims.

About halfway in there was a bit of resistance. Then maybe 3/4 of the way the axle entered the differential. I turned it a bit to get it to start into the diff.

Then I stopped to put the two shims, where are cut so they need not go over the end, onto the axle. The shims were Nissan part #43036-04100 and cost $1.18 each.

Then I slide the axle the rest of the way in. It seated with a satisfying “thunk.”

First I turned the backer plate on the axle in order to align the holes in the grease catcher with those in the backer plate. I started the first bolt through the rubber grease catcher and the catcher packing gasket and then through the backer plate hole. I simply re-used the original bolts, which have a head that is flat on one side which rides up against a step in the grease catcher to prevent the bolt from spinning.

Then I started the second bolt. I slid the axle out a bit in order to align the holes in the shims on the inside of the backer plate with the bolts. Then I pushed the axle back in, hanging the shims on the bolts and making sure the two bolts when through the bolt holes in the axle casing.

Then I pushed the other two bolts through the assembly and casing, and started the new lock-nuts, provided as part of Pat Mahoney’s rear-end bolt pack. I used a 1/2″ socket to tightened the nuts onto the bolts, moving in a star pattern. First I tightened them all down to just touch the housing.

Finally I torqued down each bolt, moving in the same pattern around the axle, to 28 foot/pounds using my torque wrench (Spec, according to my Chilton’s manual, is 20-28 foot/pounds).

Here are some pictures of the re-assembled differential.

The final step was to replace the breather and drain plugs, and re-fill the differential with gear oil. I used one quart of 75-90 weight Mobil 1 synthetic gear oil.

Leave a Reply

Your email address will not be published. Required fields are marked *