Do-It-Yourself Dana Gear And Locker Install

The worst answer to any question is “if you have to ask you shouldn’t do it.” That’s the bogus answer you get from people who either cannot explain or do not want you to know. Take for example setting up differential gears. There are those who can do it and those who haven’t learned how. Setting up gears isn’t impossible, and anyone with enough practice, proper tools, common sense, and perseverance can learn to set up an axle ring-and-pinion.

However, if you set up a ring-and-pinion gearset incorrectly it can have very detrimental effects. These can range from noise to expensive gear damage to catastrophic failure. Plus, if catastrophic failure occurs at an inopportune time (say, as you are hauling a heavy trailer down the highway at extralegal speeds) it could cause an accident and possibly death. To put it bluntly, setting up gears is a great knowledge to have but something you may wish to practice considerably before you do it on a vehicle you drive daily.

We recently took an axlehousing, an ARB Air Locker, and a new set of 5.38 gears to Pacific Fabrication to get a lesson in setting up gears for the front of a trail rig. We had the pros do the install but documented how it was done to get you familiar with the process. It may seem like brain surgery, but it’s really a mix of trial and error, fine measurement, and finesse—all of which you can easily learn. In fact, many experienced gear-men seem to have an innate touch and feel to getting the correct shims and bearing preload after years of gear installs.

We don’t expect you to read this article and start setting up gears for a living, but you need to start somewhere, and most gears, such as our Sierra gears from West Coast Differentials, come with instructions. We also recommend the book Differentials by Randy Lyman and Jim Allen, available through Randy’s Ring & Pinion. Or better yet, find an experienced gear installation technician or old-time axle guy and have him help you set up your first set of gears. You may not be an expert yet, but by asking questions you could be one eventually.

If this is your first gear install then starting with a front axle like our Dana 44 is a great recommendation. The front axle sees less constant use and is thus less likely to fail should your gear install be less than perfect. It is also best to start with a housing with the old gears and differential still installed. This lets you determine the original backlash, preload, and bearing and shim settings, which is helpful for the regear. Our housing had the diff removed and the old carrier bearing and shims long gone, a setback requiring added work.
If this is your first gear install then starting with a front axle like our Dana 44 is a g
You want a housing with the original bearing caps. If you find a deal on an axle that is missing the bearing caps you should pass on it because finding proper caps isn’t cheap. We verified that the caps were in the correct orientation by matching the older marks on the caps and the housing (A), usually a letter or number stamp. We also added punch marks at the top of the caps and corresponding marks on the housing (B) to keep the caps in their original location.
You want a housing with the original bearing caps. If you find a deal on an axle that is m
Before installing the new gears and locker we removed all the old bearing races. The pinion bearing races need to be knocked out, and using a bronze or aluminum punch is best to prevent marring the housing. The rear pinion race (toward the diff cover) had three thin shims between it and the housing surface; it is important to keep these for reassembly if possible. If they are damaged, measure them with a caliper and write down the measurement.
Before installing the new gears and locker we removed all the old bearing races. The pinio

Cleaning the housing is required security against bearing, gear, and differential failure. There are oil passages, bearing and seal surfaces, and threaded holes that should all be cleaned and verified free of dirt and metal as well as cracks and scarring. A can of parts cleaner, some rags, and an old toothbrush work wonders when mixed with elbow grease.
Cleaning the housing is required security against bearing, gear, and differential failure.
Pinion depth and pinion bearing preload are the initial steps. The pinion depth is the distance the pinion protrudes into the housing toward the ring gear. Pinion bearing preload is the amount of resistance it takes to turn the pinion and pinion bearings alone.
Pinion depth and pinion bearing preload are the initial steps. The pinion depth is the dis
If you do not have the original pinion depth shims to reuse, you will need a pinion depth tool or to go through a trial-and-error test of various shims. We cleaned and measured our original shims for a thickness of 0.0265 inch and reused them under the new rear bearing race.
If you do not have the original pinion depth shims to reuse, you will need a pinion depth

An aluminum race punch is important, as you don’t want to scar or damage the new races with a steel punch when you install them. One pinion race is installed on the gear side of the pinion opening, the other on the yoke side of the housing opening. The bearings will fit in the race, so be sure the concave opening is toward the diff cover and pinion yoke, respectively.
An aluminum race punch is important, as you don’t want to scar or damage the new races wit
Our Dana 44 has no depth shims on the pinion itself, so we installed the rear pinion bearing. This is usually done with a press but can be done with a hammer by a home mechanic. You’ll need a piece of tube and/or a spacer to press down on the bearing inner race and not the cage. Protect the pinion gear teeth by using a piece of aluminum as the anvil surface. All bearings are installed with a light coating of oil.
Our Dana 44 has no depth shims on the pinion itself, so we installed the rear pinion beari
The pinion bearing preload shims (arrow) allow the bearings to come toward each other a certain amount and up against their respective races. Without these shims the bearings would bottom out on their races when the pinion nut was torqued to spec and the pinion would not turn or would require excessive force to turn. With too many shims the pinion bearing would not ride on the race and would allow too much movement for proper gear mesh. Some pinions use a crush sleeve to set pinion preload, but shims are preferred because a crush sleeve cannot be reused.
The pinion bearing preload shims (arrow) allow the bearings to come toward each other a ce

After the pinion nut is torqued to spec a preload reading is taken with a torque wrench to see how much force is required to turn the pinion in the bearings. Each axle has its own preload requirement for new gears; our Dana 44 is 14 to 19 lb-in. If below the torque spec, the bearings are too far apart and a thinner shim pack is needed; if above the spec, thicker preload shims are needed.
After the pinion nut is torqued to spec a preload reading is taken with a torque wrench to
The carrier bearings on the differential support the ring gear and carrier and allow it to spin smoothly. These bearings also need a tight preload to reduce sideways ring gear movement under load. Some axles have adjuster rings to set preload more easily, but our Dana 44 uses shims. The shims often go between the bearings and the open carrier or locker on the bearing journals. The ARB Air Locker uses specific bearings and the shims between the race and the housing, so we started by pressing the carrier bearings onto the locker.
The carrier bearings on the differential support the ring gear and carrier and allow it to
The ring gear is installed on the Air Locker with the supplied ring gear bolts. Some gearsets use left-hand thread bolts, so be careful to check. The ring gear should be cleaned and all holes checked before dropping it on the carrier, then the bolts should be torqued to spec with Loctite. Installing the ring gear may require soft taps from a bronze, aluminum, or rubber hammer. The ring gear can also be heated slightly so that it expands and more easily drops on the carrier.
The ring gear is installed on the Air Locker with the supplied ring gear bolts. Some gears

We assembled the ring gear and differential with carrier bearings, races, supplied ARB master shims, and the seal housing in the Dana 44 housing and found that there was a large gap; note that the bearing rollers are visible (arrow). We pushed the bearings and assembly to one side and measured the gap with a feeler gauge to find a starting point for a shim pack. Then we split that measurement in half and put shims of that thickness on each side.
We assembled the ring gear and differential with carrier bearings, races, supplied ARB mas
We installed shims on both sides of the housing, holding them in place with grease. Then we reinstalled the carrier, looking for a good preload. The preload should be tight, but the backlash is something you can measure.
We installed shims on both sides of the housing, holding them in place with grease. Then w
Backlash is the distance the ring gear turns each direction before it engages the pinion gear. In our Dana 44 the backlash is specified at 0.006 to 0.010 inch, and this is the movement of the ring gear tooth as measured by our Yukon dial indicator.
Backlash is the distance the ring gear turns each direction before it engages the pinion g

If the backlash is too much, the gears are not meshing closely enough and the ring gear needs to be pushed toward the pinion. If the backlash is too little, the gears are engaging too much and the ring gear needs to be moved away from the pinion. Adjusting this is as easy as moving shims from one side to the other. Removing the carrier is easier with a wrench on a top ring gear bolt, and a prybar against the bottom bolt, but don’t let it fall out on the floor and damage the gear.
If the backlash is too much, the gears are not meshing closely enough and the ring gear ne
Once backlash is set then you’ll add shims for proper preload. The exact amount is determined by the axle you’re assembling; for a Dana 44, about 0.015-0.0075 per side. Wrestling the ARB Air Locker with the shims external of the carrier bearings is a three-hand magic trick. The shims, some paper-thin, must be gently installed and not wrinkled as the locker and bearings are tapped in place with a rubber mallet. Persistence and care pay off, but muttered four-letter words are not uncommon, especially from the first-time gear apprentice.
Once backlash is set then you’ll add shims for proper preload. The exact amount is determi
If the carrier you are using requires the shims to be run under the carrier bearings, you may want to invest in a set of mockup bearings such as these from Yukon. They have a slightly larger fitment to slide easily over the carrier journals for easy shim adjustment. They are replaced by proper bearings for final setup. Yukon also has a line of bearing pullers for easier damage-free removal.
If the carrier you are using requires the shims to be run under the carrier bearings, you

Before final assembly be sure you have any inner axle seals in the housing for axleshafts. These are usually only found in front axles and should have a light coating of grease applied.
Before final assembly be sure you have any inner axle seals in the housing for axleshafts.
Running a pattern check on the ring gear can tell you a lot about the setup you have achieved and is most important if the pinion gear is too deep or shallow, requiring an increase or decrease in your pinion depth shims. Because we are running this low pinion axle in the front location we are more concerned with the pattern on the coast or angled side of the gear tooth, as that will be the side we are running on when driving forward.
Running a pattern check on the ring gear can tell you a lot about the setup you have achie
Once the pattern and pinion depth are approved, it is time to install the pinion seal. The pinion seal gets a thin coating of silicone between it and the housing for additional leak-free service. Grease is applied where the pinion and axleshafts come through the seals for easy assembly.
Once the pattern and pinion depth are approved, it is time to install the pinion seal. The

We are running a Dana 44–to-Toyota driveshaft pinion flange from Parts Mike, allowing us to use a small, robust Toyota driveshaft joint. The pinion nut used for final assembly should be new and have a thin coat of Loctite.
We are running a Dana 44–to-Toyota driveshaft pinion flange from Parts Mike, allowing us t
The ARB Air Locker requires that care be taken when installing the seal housing O-rings, and drilling and tapping the housing for the bulkhead fitting to the air line. The gear and locker assembly should be removed during drilling and all drill and tap shavings caught, collected, and cleaned out of the housing prior to final assembly.
The ARB Air Locker requires that care be taken when installing the seal housing O-rings, a
Routing the internal brass air line safely will ensure trouble-free ARB Air Locker use. Any shims outside of the seal housing may need to be notched to clear the brass line.
Routing the internal brass air line safely will ensure trouble-free ARB Air Locker use. An

SOURCES
Pacific Fabrication 235 Tennant Ave. Unit 2 Morgan Hill CA 95037 408-250-1772 www.pacificfab.net	Yukon Gear & Axle 10411 Airport Road Everett WA 98204 866-631-0196 www.ringpinion.com
Randy's Ring & Pinion (Yukon Gear) 10411 Airport Road SE Everett WA 98204 866-631-0196 www.ringpinion.com	Loctite 10001 Trout Block Crossing Rocky Hill CT 06067 203-571-5465
West Coast Differentials 2429 Mercantile Drive Suite A Rancho Cordova CA 95742 800-510-0950 www.differentials.com	ARB 800-761-8192 http://www.arbusa.com
Parts Mike N/A AK 530-885-3850 www.partsmike.com

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By Fred Williams

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Changing Gears

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