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.

Differential Prep & Paint

Today I did the rust repair and final painting of the differential. The first thing I did was to give it a quick final cleaning using Simple Green to remove and grease on the surface from handling and working with the differential case since I last cleaned it. Prior to introducing and water I replaced the fill and drain plugs, the breather, and taped off the axle openings to keep water from getting inside.

Before painting I used an acid etch to brighten up the aluminum front of the differential. I used an Eagle One Mag Cleaner which is designed for rough-finish aluminum wheels. I donned my safety glasses and heavy rubber gloves (this is acid, after all) and sprayed the aluminum liberally.

Per the instructions, I waited thirty seconds while the acid did its etching on the aluminum, which caused a fairly vigorous foaming.

Then I washed it off very thoroughly with water.

Then I turned my attention to the rest of the differential. The case itself had several rough areas where the original paint had worn off and surface rust had set in. I had previously used a wire brush to remove and loose material. Before painting, I sealed the remaining rusty areas using Eastwood’s Rust Encapsulator product, which is supposed to seal in rust and neutralize its ability to deteriorate any further. I bought a quart can for $19 and applied it using a regular paintbrush.

There was a lot of rust around the edges of the axles, presumably from the finish being chipped by rocks and stones kicked-up by the tires. I painted over all of those areas with the encapsulator.

There was also surface rust around the welds at the rear of the “pumpkin,” which I painted over.

I rotated the differential to point down so I could access the areas underneath, and completed sealing over all of the rust areas.

After allowing the Rust Encapsulator to dry for four hours, as recommended by the instructions on the can, I prepared for the finish coat of paint. I masked off the aluminum part using heavy-duty foil and some painter’s masking tape. You can tell Thanksgiving is on my mind already!

Then I removed the plugs. The paint I used is Eastwood’s aerosol Chassis Black, which was $13 for the can.

I applied two coats, waiting 20 minutes between coats.

Then I rotated the differential up again in order to apply two coats to the areas I had missed.

After allowing the paint to try for several hours, I moved the differential into the garage to dry over night. I removed the masking from the aluminum area.

Overall I’m pleased with the results, particularly compared to the way it looked when I pulled it off the car.

Misc Parts Cleaning

This afternoon I cleaned up some miscellaneous parts that were laying around the garage. Some of these will be rebuilt, some painted, and some eventually sent off for powdercoating or plating. I used Simple Green and scouring pads.
Here are some body-frame clips and the bracket from the differential onto which the emergency brake mounts.

Here is the driveshaft and the two steering columns.

And here are the front hubs, wheel spindles, and calipers.

Rear Wheel Hub Removal, Part II

Two weeks ago I was removing the rear axles from the differential and had trouble getting the left axle free–it was stuck in place. I learned a trick from Dave Kaplan on the forums at that solved that problem. Here is the stubborn axle in place. I tapped it with a rubber mallet to no avail. A slide-hammer should work, but I didn’t have one on hand.

So what I did was this: replace the brake drum on the hub, only put it on in reverse (inside-out if that helps). Then put the lug nuts on and tighten them down only a couple of turns.

What I don’t have a picture of, because I had to use both hands and therefore put the camera down, is what I did next: grab the drum at three and six o’clock and push it in and then pull it back out so it taps against the lugs. Repeat a few times and it is a homemade slide-hammer. After just a few pulls the stubborn axle came right out.

Here are shots of the inner axle backer plate with the wheel bearing and collar and the differential’s axle housing, which still holds the inner oil seal inside.

Rear Wheel Hub Removal, Part I

This evening I started removing the rear wheel hubs so that I can clean-up and re-build the rear brakes.

I started by simply pulling the brake drums off. With the wheels removed from the hubs, there was nothing mechanically holding the drums in place. The drums were aluminum and finned.

Here is the hub after the drum was removed. On the right I began to pull the brake shoes off. They are spring-loaded and I first tipped on shoe forward and off its mounting point.

Then I freed the other end of the shoes from its mounting point and popped the shoe assembly free.

Here is a shot of the hub after the shoes were removed.

The hubs have a backer plate that bolts directly to the rear axle. I removed the four bolts that make this connection using a 1/2″ socket.

With those bolts removed the hub came free, with the half-section of axle attached! Apparently the wheel hubs need to be backed off the inner end of the axle.

Both the hub backer plate and the end of the axle case had shim/gaskets on them. Below left the rear wheel bearings are visible up against the backer plate.

I will need to have the bearings pressed off in order to get the brake assemblies off the axle. That is something for another day.

Draining the Differential

I drained the oil from the differential in preparation for disassembling the rear wheel hubs and axle. Fist I propped the differential up on my jackstands, to provide better access to the plugs. Having spent an hour yesterday and another hour this afternoon cleaning it, the diff looked pretty nice at this point.

I started by removing the breather, using a 5/8″ socket.

On the right rear of the differential are a fill plug and a drain plug. It is always a good idea to ensure that the fill plug comes out prior to removing the drain plug and draining the differential. I used the drive of my 1/2″ drive socket to loosen the fill plug.

I removed the fill plug and then positioned my oil pan underneath the differential in preparation for draining.

Then I removed the drain plug: first using my 1/2″ drive breaker bar to gain some leverage and break it loose, then using the socket wrench with no socket, then spinning it off the last few turns so I could catch it in my hand.

Then the oil drained out of the differential. It smelled a little sour, but I suppose that is normal.

I lifted the axle up on each end in order to drain as much of the oil as possible. I will replenish the differential oil after I’ve done some work on the rear brakes. I don’t know what all the fuss is about–it is easy to change the differential gear oil, all you have to do is remove the rest of the car from the diff first!

Emergency Brake Arm Removal

This afternoon I removed the emergency brake assembly from the rear of the differential and then gave the diff a second cleaning. The e-brake assembly consisted of an arm that spanned the two rear brake drums and would apply pressure to the brakes if the lever in the car was pulled. The e-brake cable, attached to the handle in the car, attached to a bracket on the right side of the differential. I began at the wheels and worked my way in.

Starting on the right side, I unscrewed the Philips head screw that held the spring tensioner to the brake cylinder.

With the screw loose the small tab could slide outward towards the wheel hub, relieving the pressure on the spring.

On the right side the arm was attached to the brakes by a pin which had a cotter pin through its bottom. I pulled the cotter pin and then worked the retainer pin up and out of the arm.

This allowed me to disconnect the right e-brake arm from the wheel hub.

On the left side was a similar set-up. I loosened the spring screw, and removed the spring from the hub. Then I removed the cotter pin and tapped the retaining pin free using a nail-set and mallet.

That freed the left e-brake arm from that hub.

Just right of center, the two arms that activate the left and right rear brakes came together on a pivoting arm; this is where the emergency brake cable came in. I removed this mechanism next. First I pulled out the cotter pin below the mechanism and pulled off the retaining washer.

Then the piece slide of a bracket mounted onto the differential case.

In order to slide the assembly off the differential, because the left arm fed through a small loop on the diff. I had to remove the spring assembly from that end in order to pull the arm back through the loop. I removed the mounting screw and then pried the retaining bracket back to get the spring piece off the arm.

Then I removed the rubber cushion from the inside of the loop an order to slide the left arm through the loop and off the differential.

The center linkage for the e-brake mounted to a bracket on the differential. I removed this by taking out the two bolts using a 1/2″ socket.

After removing the emergency brake linkage from the rear wheel hubs and differential, I spent another hour cleaning the differential. More Simple Green and a good scrubbing with some #2 steel wool pads made it come remarkably clean.

Differential, Clean-Up

This afternoon I pulled the differential out of the garage and started on it. It clearly was in need of a good cleaning. My plan for the rear end is to leave the differential gears alone and just address the rear brakes, grease seals, and wheel bearings. This afternoon I spent around an hour cleaning off much of the years of dirt, grease, and grime.

Here is the differential as it was when I pulled it off the frame:

I removed the hard brake lines that connect to the right and left rear brake cylinders from the junction with the soft rubber line above the center of the differential. I used a 7/16″ open wrench to loosen the hydraulic fittings after spraying on some Liquid Wrench. The lines came off without much trouble.

I removed the line on the left side in the same manner.

Here are the brake lines removed.

Then I spent a full hour cleaning the differential and axle case. I used some Simple Green, a wire brush, and a lot of scouring pads. Much of the dirt came off and revealed that the black paint on the differential is actually in pretty good shape. There are some surface rust areas, but nothing to be overly concerned about.

Drive shaft

This week I am off from work for a bit of a summer vacation. I don’t have any travel plans and hope to spend some of these days making some progress on the roadster. I need to start pulling pieces from the frame so that I can clean it up and eventually paint it. The frame is covered in a thick coating of grease, dirt, and road grime. Although there is some flakes of rust, overall the frame is very solid.

This morning I began by removing the drive shaft. The drive shaft transfers the engine’s rotating motion from the crankshaft through the transmission back to the differential, which then spins the rear axle and tires. The drive shaft is connected to the transmission and the differential by four bolts at each end.

I removed all four of the bolts using a 12 mm wrench and a 12 mm ratcheting wrench to loosen the nuts. Then I dropped that end of the drive shaft, which is hinged at each end allowing it to pivot out of the way.

Here is a shot of the end of the differential where the drive shaft mates to it.

Next I proceeded to the connection between the drive shaft and the transmission. It was connected by four of the same-sized bolts.

I removed all four of the nuts and bolts using two 12 mm box wrenches. Below, right is a picture of the transmission where the drive shaft connects.

Then the drive shaft was entirely removed. I put it aside for cleaning and painting. The shaft actually is composed of two pieces that slide together with groves and teeth to prevent one section from spinning on the other.