ARB Locker Install

ARB locker installed on a 1988 isuzu trooper by Sam the Isuzu Man

Click on any image for a larger version

Tools need to install locker:

• Basic hand tools
• 7/16 drill bit
• 1/4 pipe thread tap
• 3/16 drill bit
• Micrometer
• Dial indicator with vise grip or magnet base
• Bearing puller

Remove rear wheels and remove brake caliper:

Remove bolts that holds axle into housing and remove axles
Note: you do not have to remove the axles all the way.
Pull the axles out far enough to remove the rear diff. From the housing

Remove the bolts from the drive shaft. Remove the bolts that hold
The rear diff to the axle housing
Remove the rear diff. From the axle housing. .

Mark the caps that hold the diff cage in place to insure they
Go back in the same place
Remove the caps and use a pry bar to remove the diff. Cage from housing
Do not remove the pinon from the housing.

Remove the bolts from the ring gear and remove the ring gear.
Clean all bolts and ring gear.

Remove the bearing from the ring gear side of the cage and remove the
Shims from under the bearing.

Note: buy new side bearing before doing this install. Some times the side
Bearings will not come off with out the bearing being destroyed.
Install the old shims onto the locker, ring gear side and install the bearing.
Install the bearing onto the other side with no shims.
Install ring gear onto cage and use loctite #290 on threads for ring gear bolts

Note: cover the pinion with a clean shop rag to keep the
Metal shavings out of the pinion and the pinon bearings
Drill a 7/16 hole into the top left side of the rear diff housing.
Using a good drill bit this was not that hard to drill through.

Using the 1/4 pipe thread tap, cut the threads into the housings

Install the locker into the housing for trial fit.
Using the shims supplied by arb, install enough shims to remove
The side to side play of the ring gear.

Using a dial indicator check the back lash of the ring gear.
Back lash is the clearance between the ring gear and the pinion gear.
Without moving the pinion, move the ring gear back and forth
The movement that you get is called back lash. Back lash should be
.004 to .007. If back lash is less then .004 then remove shims
From the ring gear side bearing. If back lash is more then .007 then
You will have to install shims on the ring gear side.
The ring gear side bearging will have to be removed if adjustment is needed.
Now bearing preload needs to be set.
Preload is how tight the bearing sets against the bearing race.
To set preload install a .003 to .005 shim on the right side of the cage
With the shims that arb supplied. This will set preload on the bearing

Using a 3/16 drill bit, drill a hole threw the right bearing cap for the
Air tube. This hole should be within +/- .010 for tube to fit properly

Remove the locker at this time and install 2 o-rings for the seal housing.
Besure to lube seals and install seal housing and all shims that were
Selected for back lash and bearing preload.

Install locker back into housing and install bearing caps back to there
Proper place. Tighten bolts to 79 ft lb
Bend tubing around to hole that was drilled in to housing and install the
Small compession nut and then the 3/16 ferrule onto the metal tube.
Then screw the compression nut to the fitting for the housing
Apply thread sealer to the fitting for the housing
Then screw the fitting into the hole in the housing and tighten fitting
Then tighten 3/16 nut to fitting in housing
They say you may have to cut the metal tube, but installed with the right
Bend no cutting will be needed

Apply sealer to axle housing and reinstall diff. Into housing.
This is what the fitting will look like when it is install.
Reinstall drive shaft and axles. Install calipers and wheels.
Refill rear diff with proper fluid , 80w90 gear oil.

Install prssure switch and soleniod to compressor.
Find a place in your truck to mount the compreesor. I have
Mounted my compressor on the right fender well, inside of the truck

Find a place to mount the compressor switch and the locker switch
Lay the wiring harness out and find the end with three groups of wires.
This end will go the the switches. The switches are numbered as follews
Isolating switch for the compressor.
Pin# 2 red/yellow wire
Pin#3 red wire
Pin#6 blue/white wire
Pin#7 black wire
Pin#8 black wire

Switch #1 of wiring harness
Pin#2 red wire
Pin#3 yellow wire
Pin#6 blue/white wire
Pin#7 black wire
Pin#8 black wire

Switch #2 of wiring harness will be used if a second locker is
To be installed later

Blue/white wire of harness is to be connected to dash lights.
The color of wire you will be looking for is green with red strip.
This is the color of the wire Isuzu uses in all makes for marker
And dash lighting.

Connector the red/yellow wire to a key on power supply.
There will be a white connector taped to the wiring harness with
4 wires. Install wires that match up to the color of wires
coming from the switch harness. All 4 wires are used.
Route the wiring harness to the compressor and connect the
red wire and the blue wire to the pressure switch. It does not matter
which pin the wires are connected to.

Connect the white connector with the yellow and black wire to
the soleniod at the compressor. Other connector is for a second locker.
With a red and black wire left, connect red wire to possitive side of
batt. And black wire goes to ground side.

Now it is time to install blue tubing from compressor to locker.
At compressor push the blue line into the soleniod. Route the
line to the locker. Tie the line to body and or fram as needed.
Route the line down to the locker and be sure to leave enought line
for down travel of the rear axle. A good place to tie the line is the rear
brake line to the rear axle. Install the spring over the tubing.
Install the top compression nut, install the 5mm ferrule.
Install the compression nut to the fitting in the rear housing.
Install relay into connector of switch/compressor wiring harness.
Turn on compressor and let run untill it cuts off and then turn on
switch for locker. I was able to here the locker engage
at this time.

-Sam