low Buck Axle Build - bearing Install - Photo 40208347

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New bearings, and those shim packs we just mentioned, are pushed into place on the hydraulic press. If you don’t have access to a press, it might be best to hire this job out. However, careful hammering and the correct-sized tubing can be used to drive the bearings into place.

Here’s the subject of our affection after it was pulled out from underneath the ’78 Bronco. If you look closely, you can see the broken U-joint in the passenger-side knuckle (foreground).

It is possible to rebuild the Dana differential with it still under the truck, but we chose to fully strip the frame of our 4x4 to have it blasted and powdercoated, so the axle was removed. The first step in the teardown is to pull the locking hub caps and disassemble the locking hub, beginning with the large clip that holds the selector in place. It’s a good idea to take pictures of each step to help you remember exactly how things go back together during reassembly.

Two hub nuts sandwich a locking plate to keep the hub in place. It’s best to purchase the specialized socket to remove the nuts. Using an old screwdriver or chisel and hammer to spin the nuts on or off can cause damage and put metal chips in the wheel bearings.

Once the hub and brake rotor is off, the spindle, brake caliper bracket, and backing cover are all revealed. Remove the nuts from the spindle to remove the entire assembly from the steering knuckle.

Time, abuse, and rust had caused practically everything to bond together in one iron lump. Eventually, after a lot of penetrating fluid and a little hammer persuasion, the spindle, caliper bracket, and backing cover all came off together. The axles slide right out at this point.

To get the steering knuckle off, first remove the two nuts securing them to the end forging. Then give the knuckle a couple of hard hits with a rubber mallet and it should pop right off.

Once the steering hardware on either end was stripped, we pulled the center cover to take a look at the center chunk. The bearings and races must be replaced, but the gears, thankfully, show no signs of damage or rust from water in the housing. We’ll keep them and put the savings toward the new bearings.

With everything torn apart we took the salvageable pieces to be sandblasted. Be sure not to blast the bearing surfaces. Thoroughly clean out all the grit from the housing and other components.

This may be the ugliest $90 we’ve ever spent, but the axleshaft you are looking at represents less than half the cost of an OEM replacement. A quick eBay search turned up Ventures Truck Parts & Equipment, which specializes in used 4x4 drivetrain components. The company handled yanking the part we needed and shipping it; we were obviously left with the duty of cleaning it up.

Jim Cook of Jim Cook Racing Transmissions specializes in racing and handles gears and transmissions for several NASCAR Nationwide and Truck Series race teams, but he also works with 4x4 drivelines. Here, he uses a bearing puller to remove the carrier bearings from the differential.

The Dana 44 uses shims to set the ring gear backlash. If you aren’t replacing the ring-and-pinion, you can simply put the shims back and keep the setting where it was. The process of setting backlash by adding and removing shims can be time consuming and tedious, so avoid the possibility of getting your shim packs mixed up by taping them together and labeling them as soon as they come out of the housing.

New bearings, and those shim packs we just mentioned, are pushed into place on the hydraulic press. If you don’t have access to a press, it might be best to hire this job out. However, careful hammering and the correct-sized tubing can be used to drive the bearings into place.

Part of the consumables kit we got from Randy’s Ring and Pinion included new Spicer U-joints. They are higher quality than standard parts-store stuff. Hopefully we will be able to avoid another broken U-joint and axle.

The axles ride on Torrington-style bearings pressed inside the spindles. They can be a pain to get out, so Cook uses a die grinder to carefully cut away the cage. Once he’s cut through, the bearing will pop right out.

The new bearings are pressed in with light taps from a hammer on a properly sized socket that matches the outside diameter of the spindle bearings. Don’t forget to grease the new bearings.

Cook always applies plenty of assembly lube to all roller bearings before reassembly. This reduces the chance of a bearing getting too hot before the gear oil can work its way into the bearings the first time the truck runs again. You may also notice plenty of grease on the pinion shims. Lubrication isn’t necessary here; the grease simply keeps the shims stuck in place while Cook drops the pinion into position in the housing.

Randy’s Ring & Pinion also has new axle seal kits. This hard plastic doughnut is part of the kit and only goes on one way. Make sure the chamfered edge goes down against the flange on the outer axles

Another C-shaped seal fits inside the spindle. In this case, make sure the concave side of the seal points in toward the spindle to help hold the bearing grease in.

Take a moment to test fit everything to make sure you have the ball joints in the right places. The ball joint with the provision for a cotter pin goes in the top of the end forging pointing upward. (The housing is upside down in this photo.)

The ball joints only press in from one direction. Once in, retaining clips are installed to make sure they won’t back out later.

When installing the steering knuckles the lower ball joint nuts have to be tightened to spec first. It can be difficult to tighten the nuts sufficiently if the ball joints want to spin in their sockets. Cook shows how to overcome this by using a large pair of pliers to squeeze the knuckle against the end forging on the housing to compress the ball joint so it won’t spin. Once the lower ball joints are tight you can install the upper ball joint seats and tighten them and the upper ball joint nuts to spec.

Before installing the center chunk, make sure to install new inner housing seals if necessary. Many people will skip this step, but if the housing is torn down this far it only makes sense to install new seals here while you have the chance.

With the inner housing seals in place, Cook gently lowers the center chunk into the housing. Notice that the races are held onto the bearings with a generous amount of assembly grease. If you don’t do this the races always seem to pop off and go rolling around the shop floor at the worst times.

Because of the shims used to control lash, the center chunk is a bit of a press fit into the housing. Cook uses a hammer and a blunt chisel to nudge things along. Only use the chisel on the cast carrier case, not the bearing races or the ring gear. A brass or deadblow hammer also works well.

Grease the splines of the axleshafts to help prevent damage to the inner housing seals. Slide the axles into place through the hole in the knuckles. Make sure the splines index into the differential properly and all the way.

Next to go on are the caliper brackets and spindles. The bolts on some Dana 44 steering knuckles are irregularly spaced so that the bracket can only go on one way. This ensures that the caliper is clocked so that the calipers will be properly located.

Properly pack the wheel bearings with high-temperature disc brake grease. You can do this by hand by slapping the bearing in a wad of grease in your palm or you can use a bearing packer.

Install and adjust the wheel bearing nuts to spec and check that the rotating assembly is not binding or loose and sloppy.

This lock disc sandwiches between the two hub nuts and has a tab that slides down a groove cut along the length of the spindle. One of the hub nuts on each side has a pin. It should go on first with the pin pointing outward. Keep adjusting the nut so that the pin fits into one of the holes on the lock disc once it is slid into place. Now thread on the second hub nut and tighten it down with the proper tool. Finish it off by installing the locking hubs.

We didn’t even bother trying to track down a gasket for the cover. A quick bead of silicone works just as well, if not better.

Here’s the completed axle back underneath the Bronco frame. Don’t forget to fill it with oil. We still have a long way to go, but at least we’ve gotten one more thing scratched off the to-do list.