ARB RD110 User Manual

RD110

MITSUBISHI IFS, 28 SPLINE

INSTALLATION GUIDE

Part No. 2102110

Revision Date 26/07/07

Copyright © 2007 by ARB Corporation Limited

No liability is assumed for damages resulting in the use of the information contained herein.
ARB Air Locker Air Operated Locking Differentials and Air Locker are trademarks of ARB Corporation Limited.
Other product names used herein are for identification purposes only and may be trademarks of their respective owners.

ARB 4x4 ACCESSORIES

Corporate Head Office

42-44 Garden St Tel: [phone]
Kilsyth, Victoria Fax: [phone]
AUSTRALIA
3137

Australian enquiries [e-mail]
North & South American enquiries [e-mail]
Other international enquiries [e-mail]

www.arb.com.au

Table of Contents:

1 Introduction 3

1.1 Pre-Installation Preparation 3

1.2 Tool-Kit Recommendations 4

2 Removing the Existing Differential 5

2.1 Vehicle Support 5

2.2 Differential Fluid Drain 5

2.3 Removing the Differential Assembly 5

2.4 Marking the Bearing Caps 6

2.5 Checking the Current Backlash Amount 7

2.6 Removing the Differential Center 8

3 Installing the Air Locker 9

3.1 Approximate Backlash Shimming 9

3.2 Calculation & Selection of Backlash Shims 11

3.3 Mounting the Ring Gear 12

3.4 Installing the Carrier Bearings 13

3.5 Preload Shim Measurement 14

3.6 Drilling & Tapping the Bulkhead Port 16

3.7 Installing the Bulkhead Fitting 17

3.8 Installing the Seal Housing 17

3.9 Installing the Differential Center 18

3.10 Setting Up the Bulkhead Fitting 20

3.11 Final Assembly 21

3.12 Checking the Backlash 23

3.13 Bench Testing the Air Locker 24

3.14 Reinstalling the Differential Assembly 25

4 Installing the Air System 26

4.1 Mounting the Solenoid 26

4.2 Running & Securing the Air Line 28

4.3 Connection to the Bulkhead Fitting 29

5 Mounting & Connecting the Electrical System 31

5.1 Mounting the Actuator Switch(es) 31

5.2 Wiring the Actuator System 32

6 Testing & Final Assembly 35

6.1 Leak Testing 35

6.2 Testing the Air Locker Actuation 35

6.3 Re-Sealing & Filling the Differential 36

6.4 Note For ADD Equipped Vehicles 36

6.5 Post-Installation Check List 37

7 Parts List 39

7.1 Exploded Assembly Diagram 39

7.2 Itemized Parts List 40

1

2

1 Introduction

IMPORTANT :

BEFORE ATTEMPTING TO DISMANTLE YOUR VEHICLE FOR THIS

INSTALLATION, PLEASE READ THIS INSTALLATION GUIDE IN ITS

ENTIRETY, AS WELL AS ALL APPLICABLE SECTIONS OF YOUR

VEHICLE MANUFACTURER’S SERVICE MANUAL.

1.1 Pre-Installation Preparation

This booklet is to be used in conjunction with your vehicle
manufacturer’s service manual. ARB endeavors to account for every
possible variation in vehicle model when publishing its installation
guides, and guides are updated regularly as new model information
becomes available, however, the rapid and globally varied release of
some vehicles makes it difficult to insure that your vehicle model has
been accurately accounted for. In the case of any technical
discrepancies between this guide and your service manual, we
strongly advise that you adhere to the specifications and techniques
as documented in your service manual.

Although your ARB Air Locker comes complete with all the step by
step instructions you will need to supplement your vehicle
manufacturer’s service manual and install your new differential, ARB
recommends that you have your Air Locker installed by a trained
professional. Many ARB distributors around the world have been fully
instructed in Air Locker installations by ARB, and have gained a wealth
of experience and skill from years of performing similar installations.

Once you begin this installation your vehicle will be immobile until all
steps of the installation are complete. Make sure your Air Locker kit is
the correct model for your vehicle and that it contains all of the parts
listed on back cover of this booklet. Also be sure you have
appropriately equipped yourself with all the necessary tools, parts, and
materials to complete this installation (see Section 1.2 Tool-Kit
Recommendations), and that you have allowed for an appropriate
amount of vehicle down time.

HINT : Place a mark inside each of the c symbols as

you complete each step. It is very important NOT to
miss any of the steps!

3

1 Introduction

1.2 Tool-Kit Recommendations

Below is a list of tools and supplies you may need to complete this
installation. Requirements for your vehicle may vary. Please consult
your vehicle service manual for additional recommendations.

1.2.1 Tools

c Standard automotive sizes (metric and/or imperial) of sockets,

wrenches, Allan keys, and drills.

c A dial indicator or other suitable measuring tool for checking ring &

pinion backlash.

c A razor knife for nylon tubing.
c A differential housing spreader to facilitate removal and installation

of the carrier.

c A torque wrench (See vehicle service manual for required torque

range)

c A lubricant drain reservoir.
c A slide hammer for removing CV axles.
c Suitable measuring tools to measure a differential for preload

shimming. (e.g., an automotive feeler gauge)

c A 11.2mm [7/16”] drill and ¼”NPT tap for bulkhead fitting

installation.

c An automotive bearing puller (2 jawed) or a differential carrier

bearing puller.

c A bearing press or arbor press.

1.2.2 Supplies

c Thread lubricant/sealant compound for pressure fittings

(e.g., LOCTITE #567 Teflon paste)

c Thread locking compound (e.g., LOCTITE #272)
c A gasket sealant or replacement gasket for your differential.
c A sufficient volume of differential oil to completely refill your

housing. (see the ARB Air Locker Operating and Service Manual
for recommended lubricants)

c A soap and water mixture to test for air leaks.
c A selection of differential bearing shims to set-up preload and

backlash.

4

2 Removing the Existing Differential

2.1 Vehicle Support

c Safely secure the vehicle on a hoist. We recommend supporting

the vehicle on a chassis hoist to keep the differential area at a
convenient working height and to leave the wheels and axles free
to be rotated and removed.

c Once supported in the air, chock the wheels (if necessary) and

leave the vehicle in neutral.

2.2 Differential Fluid Drain

c Clean around the differential drain plug to prevent dirt from entering

the differential.

c Position a fluid drain reservoir under the differential.
c Remove the drain plug and drain all of the oil from the housing.

HINT : This is a good time to check for metal particles in

your oil and on the end of the magnetic drain plug,
which may indicate a worn bearing or differential
component.

c Once drained, reinstall the drain plug.

2.3 Removing the Differential Assembly

c Remove the stub axles from the differential housing according to

your vehicle manufacturer’s service manual.

NOTE : Rubber oil seals can be easily damaged. Support the

weight of the axle when extracting it across the edges
of the seals.

c Disconnect the drive shaft from the pinion flange.
c Completely remove the entire differential assembly.

5

2 Removing the Existing Differential

2.4 Marking the Bearing Caps

c Secure the differential assembly to a workbench.
c Completely remove the front access cover.
c Using a small pointed center punch, gently mark the bearing caps

in a way that will enable you to know which cap is ‘LEFT’ and which
cap is ‘RIGHT’, which way is ‘UP’ and which way is ‘DOWN’.
(Fig.1.)

c Mark the right hand cap in a similar way.

Figure 1.

HINT : Many installers choose to make one punch mark on

the left hand side of the left hand bearing cap and a
similar mark on the housing at close proximity to the
cap mark. The right hand side is then designated with
two punch marks on the right hand side of the cap and
two similar punch marks on the housing.

6

2 Removing the Existing Differential

2.5 Checking the Current Backlash Amount

IMPORTANT:

This step is a precautionary measure recommended by ARB due

to the fact that some aftermarket ring and pinion sets have been

manufactured to run with different backlash settings than those

specified by your vehicle manufacturer. Although ARB must

recommend you set backlash according to your service manual

guidelines, we also advise that you compare the backlash

measurements taken here to the recommended backlash settings

in your vehicle service manual. Measurements found to be

outside of your service manual recommendations may indicate

the need to deviate from those settings in order to achieve quiet

running with a good contact mark.

Refer to your vehicle service manual or your local authorized

ARB installer for more information.

c Set a depth indicator on one of the ring gear teeth as in Figure 2.

Figure 2.

c While supporting the pinion gear by holding the drive shaft flange,

rotate the differential in both directions while observing the
maximum variation in depth from the indicator (i.e., the highest
value minus the lowest value). This value is referred to as the ring
and pinion backlash.

c Rotate the differential center 90° and measure again for accuracy.
c Record the average of all measurements.

7

2 Removing the Existing Differential

2.6 Removing the Differential Center

c Remove the floating shaft (or ADD unit if present) from the side of

the differential housing.

c Remove the bearing cap retaining bolts and then remove both

bearing caps.

c Gently pry the differential center forward until it comes free of the

housing.

NOTE : Be sure not to mix up the left and right hand tapered

roller bearing cups or preload shims. Later it will be
necessary to know which cup came from which
bearing and which shim came from which side of the
differential.

8

3 Installing the Air Locker

FACTORY DIFFERENTIAL

3.1 Approximate Backlash Shimming

In order to reproduce a similar preload and ring and pinion backlash in
your Air Locker to that of your existing differential, measurements
need to be taken so that a shim thickness can be calculated.

c Secure the differential to a workbench.
c Remove the bolts that hold the ring gear in place.
c Using a plastic or copper hammer, tap in a circle around the ring

gear to separate it from the differential carrier.

c Remove the original bearings and shims from the differential center

using a bearing puller.

NOTE : Keep the bearings and shims separated so that they

can be identified as to which end of the differential

c Examine the bearing cup and cone from Figure 3. for damage or

wear and, if necessary, discard it and replace it with the same size
and type of bearing.

they came from.

Figure 3.

9

3 Installing the Air Locker

RING GEAR

AIR LOCKER DIFFERENTIAL

c Using a caliper or similarly accurate measurement method

(i.e., able to take accurate measurements within 0.04mm [0.0015”]),
measure the distance from the shoulder of the bearing journal to
the ring gear mounting face (shown as ‘A’ in Figure 3.) and record
this measurement as ‘A’.

c Measure the thickness of the factory shim removed from the end of

the differential carrier (shown as ‘B’ in Figure 3.) and record this
measurement as ‘B’.

FLANGE

Figure 4.

c Measure the distance from the Air Locker bearing shoulder to the

ring gear mounting face (shown as ‘C’ in Figure 4.) and record this
measurement as ‘C’.

10

3 Installing the Air Locker

3.2 Calculation & Selection of Backlash Shims

Ideally, the measurement you recorded as ‘C’ from the Air Locker
differential will closely match ‘A’ on the existing differential (within

0.1mm [0.004”] ) and then the factory shim can be reused, however,
quite often these measurements will vary slightly between one factory
differential and the next.

If this is the case you must create a new shim pack thickness by using
the measurements you recorded earlier to find a desired measurement
for ‘D’ in Figure 4.

Use the following calculation:

A + B – C = D (Replacement Shim Pack)

HINT : If your calculations are correct then the following

calculation will also be true:

A + B – C – D = ZERO

c Create a shim pack to match the thickness calculated as ‘D’.
To achieve the desired shim thickness you can:

• Machine down the factory shim thickness.

• Add shims between the factory shim and the bearing cup.

HINT : A selection of shims of this size have been supplied

with your Air Locker kit.

• Purchase new factory shims at the desired thickness.

• Use a universal shim kit available from most drive train

specialists.

• Add small amounts of shim between the bearing cone and the
bearing seat.

NOTE : NEVER machine the Air Locker.

11

3 Installing the Air Locker

3.3 Mounting the Ring Gear

IMPORTANT:

As the Hyundai Terracan has Ø12mm ring gear bolts, fitment to

this vehicle will require drilling the flange holes of the Air Locker

from Ø10.2mm to Ø12.2mm [31/64”] to suit.

c Apply a thin film of high pressure grease to the ring gear shoulder

of the Air Locker to prevent seizing.

c Thoroughly clean any thread locking compound or other foreign

matter from the holes of the ring gear, the threads of the ring gear
bolts, and the mating surfaces between the ring gear and the Air
Locker flange.

HINT : Stoning the ring gear mounting face before

installation will remove any high spots around the
threads.

c Heat the ring gear to between 80 and 100°C [175 - 212°F] in hot

water or in an oven to slightly expand the gear and facilitate
assembly.

NOTE : NEVER HEAT GEARS WITH A FLAME! This could

damage the hardened surface of the gear and result
in premature wear or failure.

c Dry the gear and bolt holes with compressed air (if wet).
c Install the ring gear onto the Air Locker by aligning the bolt holes

and then gently tapping it around in a circle with a soft mallet.
Avoid using the bolts to pull down the ring gear as this puts excess
strain on the bolts and the differential flange.

c Apply a thread locking compound to the thread of each ring gear

bolt before inserting it. Do not apply threading compound directly
into the threaded hole as this could prevent the bolt from reaching
its full depth.

c Tighten the ring gear bolts in a star pattern with a torque wrench

according to your vehicle manufacturer’s specified torque.

12

3 Installing the Air Locker

3.4 Installing the Carrier Bearings

c Apply a thin film of high pressure grease to both bearing journals of

the Air Locker.

c Using a bearing press or arbor press, press one of the original

tapered roller bearing cones onto the bearing journal opposite to
the ring gear flange of the differential carrier (As shown in Figure 5.)
until the bearing seats firmly against the bearing journal shoulder.

Figure 5.

c Invert the Air Locker and press the bearing cone which was

supplied with the Air Locker kit onto the bearing journal on the ring
gear flange side of the differential (the seal housing side) until the
bearing seats firmly against the bearing journal shoulder.

NOTE : Never re-use any bearings which are damaged or

worn. Do not add any shims between the seal
housing bearing and the bearing seat.

13

3 Installing the Air Locker

3.5 Preload Shim Measurement

In order to preload the tapered roller bearings in your Air Locker,
measurements need to be taken so that a value can be calculated for
the total shim thickness ‘E’ in Figure 6.

Figure 6.

c Hold the bearing cups in place over their matching bearing cones.
c Insert and hold the Air Locker into the differential housing.
c Insert the shim pack determined earlier as ‘D’ between the bearing

cup and the differential housing (right hand side as shown in Fig.4.)

c Push (or lightly pry) the Air Locker hard across to the right-hand

side, and measure the gap (also called the ‘end float’) between the
bearing cup and the housing with a feeler gauge (See Fig 7.).

c Record this measurement.
c Consult your vehicle manufacturer’s service manual to determine

the carrier bearing preload amount specified for your vehicle.

NOTE : If your service manual specifies preload in terms of a

torque value measured off the drive pinion flange,
then assume a preload amount of 0.25mm [0.01”] for
the following calculations. Once you have assembled
the housing to check the final backlash (Refer to
Section 3.12 Checking the Backlash) you should verify
that your preload is correct using a torque wrench and
your service manual’s table of values.

14

3 Installing the Air Locker

Figure 7.

c Add the specified preload amount to the end float measurement

determined with the feeler gauge to determine a shim amount for
‘E’ (Refer to Figure 6.).

PRELOAD + END FLOAT = SHIM PACK

c Create a shim pack ‘E’ to closely match the calculated amount.
NOTE : When creating the shim pack ‘E’, use at least 0.75mm

[0.030”] of the Air Locker shim pack between the
factory shim and the bearing cup in order to prevent
the cage of the bearing from contacting the factory

To achieve this desired shim thickness you can:

• Machine down the factory shim thickness.

• Add shims between the factory shim and the bearing cup.

• Purchase new factory shims at the desired thickness.

• Use a universal shim kit available from most drive train specialists.

NOTE : Do not add shims between the bearing cone and the

shim.

bearing seat and NEVER machine the Air Locker.

15

3 Installing the Air Locker

3.6 Drilling & Tapping the Bulkhead Port

A port must be drilled and tapped through the differential housing to
allow the seal housing tube through the housing to connect with the
air line from the air compressor.

c Remove the Air Locker from the housing.
c Mark a spot on the top of the outside shell of the differential

housing in the position shown in Figure 8. The location should be
about 45mm [1.75”] from the gasket face of the cover flange and
very close to the teeth of the ring gear inside.

Figure 8.

45mm

c Cover the drive pinion and bearing seat areas with rags to protect

them from metal filings.

c Drill through the housing square to the outside surface using a

11.2mm [7/16”] drill.

c Tap the hole from the outside using a ¼” NPT pipe tap.
c Remove any sharp edges from the hole that may chip-off and fall

into the housing.

c Carefully remove the rags and inspect with a service light inside the

housing to insure no metal filings are left behind.

16

3 Installing the Air Locker

3.7 Installing the Bulkhead Fitting

c To obtain an oil tight seal, apply a thread sealant to the threads of

the bulkhead body, screw it into the bulkhead port (from the
outside), and tighten.

c Wipe the area clean of any excess thread sealant (inside and

outside of the housing).

3.8 Installing the Seal Housing

c Apply a thin film of high pressure grease to the outside of the

tapered roller bearing cup supplied with the Air Locker.

c Using a bearing press or arbor press, press the bearing cup into the

seal housing (narrow edge first) until it stops at the end of the bore.

NOTE : Do not install the bearing cup upside down. Refer to

Figure 9. for the correct installation direction.
Be careful not to bend the seal housing tube or
damage the O-ring grooves.

Figure 9.

c Make sure the seal housing tube and the grooves of the seal

housing are clean and free from any contaminants (e.g., water, dirt,
metal filings, etc.).

c Inspect the seal housing O-rings (supplied) for dirt, damage or

other conditions which might cause leaks.

c Generously lubricate the O-rings with oil prior to assembly, then

insert them into the grooves of the seal housing.

NOTE : When assembling the O-rings, be careful not to leave

them twisted when seated in the grooves as this could
cause excessive wear and leakage.

17

3 Installing the Air Locker

c Install the seal housing onto the Air Locker by carefully sliding it

over the bearing journal by hand with a gentle twisting motion. This
will allow the O-rings to engage gently.

c Rotate the seal housing a few turns to make sure it rotates freely

and smoothly.

3.9 Installing the Differential Center

IMPORTANT:

YOU MUST SPREAD THE HOUSING.

Spreading the differential housing with a differential case

spreader is a step which is critical to set up bearing pre-load

on cast iron differential housings. Improper pre-load will

result in undue bearing wear, increased stresses in the

differential center, increased running noise, and ultimately,

ring and pinion gear damage.

c Set up a spreader and a dial indicator as shown in Fig 10.

Figure 10.

18

3 Installing the Air Locker

c Carefully spread the housing (Fig 10.) just enough to install the

differential carrier (Refer to your vehicle’s service manual).
NOTE : Never spread the housing more than 0.5mm [0.020”].
c While holding the bearing cup onto the carrier bearing, hold the

shim packs ’D’ and ‘E’ in their correct positions, then insert the Air

Locker into the differential housing with the seal housing solder joint

rotated so that it is pointing out of the differential housing.

NOTE : If the shim pack is too difficult to install then the

shims may need to be tapped in. Be careful not to

c Bend the seal housing tube around the outside of the ring gear until

the end of the tube can be inserted through the hole in the

bulkhead fitting (See Fig.11.).

damage the shim packs while installing them.

Figure 11.

c Remove the spreader.
c Install the bearing caps oriented as they were marked before they

were removed, and tighten the bearing cap bolts. It is not

necessary to torque them down at this time.
c Check that some backlash can be felt between the ring and pinion

gears. No backlash would be an early indication of incorrect shim

thickness.

19

3 Installing the Air Locker

3.10 Setting Up the Bulkhead Fitting

c Insert the end of the seal housing tube into the bulkhead fitting and

hold it to its full depth.
c From the outside of the housing, assemble the small O-ring over

the top of the small length of seal housing tube that can be seen

inside the bulkhead fitting.
c While still holding the seal housing tube at depth, insert the small

drilled end of the center compression nut over the extended tube as

shown in the assembly diagram (Fig.12.), and screw it into the

bulkhead body, and tighten.

Figure 12.

NOTE : Be sure to insert the correct end of the center

compression nut into the bulkhead body. The thread
has been partially relieved on the bulkhead side of the
center compression nut to visually identify its
orientation. (Fig.12.)

NOTE : Excessive tightening of the center compression nut is

not necessary to form a good seal around the tube
and may damage the O-ring or the threads of the
compression nut.

20

3 Installing the Air Locker

3.11 Final Assembly

The seal housing tube needs to be carefully bent so that it will stay
clear of any moving parts of the differential and not rub against any
sharp stationary edges on the bearing cap or the differential housing.

c Without using sharp, jagged tools such as pliers (usually your

hands are the best tool for this job), gently bend the seal housing

tube so that it closely follows the profile of the Air Locker and the

ring gear. (See Fig.13. & Fig.14.)

Figure 13.

Figure 14.

21

3 Installing the Air Locker

NOTE : Any contact due to vibration or shock could wear the

tube over time and eventually cause a leak. Keep the
tube away from any sharp edges of the bearing cap or
any other part of the differential housing.

c Check the gap between the Air Locker and any close points on the

seal housing tube with a feeler gauge to insure that adequate

clearance exists.

NOTE : Less than 8mm [5/16”] should be considered too little

clearance.

c Position the access cover in its installed position to check that no

part of the tube comes in contact with it.

22

3 Installing the Air Locker

3.12 Checking the Backlash

c Refer to your vehicle manufacturer’s service manual for the

specified maximum and minimum amounts of backlash. If the

backlash measured here is not within the specifications then the

differential will have to be re-shimmed.
c Tighten all bearing cap bolts with a torque wrench to the torque

specified in your vehicle manufacturer’s service manual.
c Set a plunge type dial indicator on one of the ring gear teeth as in

Figure 15.

Figure 15.

c While supporting the pinion gear by holding the drive shaft, rotate

the differential in both directions while observing the maximum

variation in depth from the indicator (i.e., the highest value minus

the lowest value). This value is referred to as the ring and pinion

backlash.

c Rotate the differential center 90° and measure again for accuracy.
c Record the average of all measurements.

NOTE : This step is only necessary when adjusting for

incorrect backlash.

c Remove the bearing caps.
c Remove the shim packs from both ends of differential.
c To decrease the amount of backlash, reduce the shim thickness ‘D’

(Fig.4.) and increase the shim thickness ‘E’ (Fig.6.) by the same

amount. Reverse this step to increase the backlash.

c Remount the differential as before.
c Check backlash again as before.

23

3 Installing the Air Locker

3.13 Bench Testing the Air Locker

c To bench test the Air Locker; when 620kPa [90 PSI] shop air is

applied to the seal housing tube, the Air Locker should engage.

c Check all fittings and the seal housing for air leaks.
c Rotate the differential carrier by turning the pinion flange whilst

applying air pressure.

NOTE : An accurate way to test for air leaks is to fit a shut-off

valve to an air pressure gauge. (Fig.16.) Once 620 KPA
[90 PSI] is reached the valve can be off, the air hose
disconnected, and the pressure gauge observed to see
if there is any drop in pressure.

Figure 16.

c If a leak is found to be present, spray a soap and water mixture

onto the bulkhead air fitting. Bubbles should appear at any leak

points.
NOTE : Do not spray this soapy mixture inside the differential.

c Check that leaky fittings have been adequately tightened.
c Disassemble, clean threads, and reapply thread sealant if leaking

persists.
c If a leak is found at the seal housing, remove the Air Locker and

carefully remove the seal housing assembly and examine the O-

rings. Be very careful with the O-rings and check for defects,

damage, wear, or presence of foreign material in the O-ring

grooves. Replace if necessary.

24

3 Installing the Air Locker

Approx.

[Ø11/16”]

3.14 Reinstalling the Differential Assembly

c Reassemble the differential assembly according to your vehicle

manufacturer’s service manual using gasket sealant where

necessary.

NOTE : Be careful not to damage the sintered bushing in the

end of the Air Locker when installing axle stubs. The
fit should be snug, and light tapping may be required
to fully insert the stub into the spline. In some cases,
a small chamfer may need to be ground onto the axle
stubs as a lead-in for insertion into the bushings.

HINT : Drilling an access hole in the right hand differential

support bracket (See Fig. 17.) allows the bolts on the
inner stub axle flanged joint to be inserted after the
differential assembly is already in position under the
vehicle. This makes reinstalling much easier.

Figure 17.

Ø18mm

hole

c Install the differential assembly into the vehicle.
c When inserting the CV axle into the differential housing a gentle tap

will be required to seat the retaining clip.
NOTE : Be careful not to damage oil seals with the axles.

c Reconnect the drive shaft flange.

25

4 Installing the Air System

4.1 Mounting the Solenoid

4.1.1 Connection to an ARB Air Compressor (Fig.18.)

c Remove one of the 1/8” BSP plugs from its port in the compressor

tank.
c Apply Teflon paste to the nipple (1/8” X 1/8” BSP) and insert it into

the port and tighten.

c Apply Teflon paste to the free end of the nipple.
c Assemble the inlet port side of the solenoid (stamped with a ‘1’) onto

the nipple and hand tighten it. The solenoid should be rotated into a

position which does not obstruct any other ports on the compressor

tank.

NOTE : The solenoid exhausts compressed air through the

center of the black retaining cap when the Air Locker is
disengaged. Make sure this orifice cannot be
obstructed.

c Apply Teflon paste to the threads of the 5mm push-in fitting and

assemble it into the solenoid outlet port (stamped “2”) and hand

tighten.

ARB

Air Compressor

Figure 18.

26

4 Installing the Air System

4.1.2 Connection to an Alternate Air Source

For ease of installation, quality of air supply, and a high level of
dependability from your Air Locker(s), ARB strongly recommends use of
a genuine ARB Air Compressor, however, the Air Locker air system can
be operated on any alternate air source that meets each of the following
guidelines:

c Must supply a minimum of 85PSI [586kPa].
c The supply must never exceed 105PSI [724kPa].
c The air source should have a tank capacity which enables it to

actuate the Air Locker(s) in one charge so that no hesitation is
experienced when locking one or two differentials.

HINT : A good way to insure that you have the necessary

capacity is to make sure you can engage, disengage, and
then reengage your Air Locker(s) without the air source
having to regenerate (e.g., without the compressor
turning on to refill the tank).

c Must supply clean air, free of rust, dirt, water, or other foreign

matter.

c Must match the 1/8” BSP porting of the Air Locker solenoid.

c Mount solenoid within close proximity of the air supply and secure it

from the effects of vibration and shock.
c Connect the air supply to the 1/8” BSP inlet port of the solenoid

(stamped “1” on the solenoid body) using thread sealant.

IMPORTANT :

ARB cannot warranty your Air Locker(s) against damage caused

as a result of using an alternate air supply. If you have any doubts

as to the suitability of your air system to use in an Air Locker

system, consult your ARB distributor.

27

4 Installing the Air System

4.2 Running and Securing the Air Line

The path taken by the air line from your air source (i.e., compressor) to
your Air Locker is unique to your vehicle and the position of your air
source. Plan ahead carefully when running the air line and always
follow these guidelines:

c Account for axle travel when running the line from the axle to a fixed

point on the vehicle. Leave enough slack in the air line to allow for

maximum suspension travel in both directions.
c Avoid leaving large lengths of air line hanging underneath the vehicle

where they may get tangled on rocks, sticks, etc.

HINT : Cable tying the air line to one of your flexible brake lines

will account for axle travel and should help keep your
line from getting snagged.

c Run the air line all the way from the compressor to the differential

before trimming either end of the line to length. This will save

complications which may arise if the air line has to be removed.
c Make sure the line does not contact sharp edges or abrasive

surfaces that may damage the air line over time.
c Do not run the air line around tight bends which may kink the air line

and restrict or block the airflow.
c Keep the air line well away from your vehicle’s exhaust components.

Air lines will melt if subjected to extreme heat.
c Do not run more air line than necessary. Excess line volume created

when coiling the left over hose, using unusually large diameter hose,

etc., will increase drain on the compressor tank resulting in the

compressor running more often than needed.

c Support the air line by tying it back with cable ties wherever possible.
c At the solenoid end of the air line, trim the line to length with a sharp

knife.

28

4 Installing the Air System

c To attach the air line to the push-in fitting of the solenoid; insert the

line firmly into the fitting, pull outward on the flange of the fitting while

holding the line as far into the fitting as possible, and then gently pull

outward on the air line to clamp the line in place.

NOTE : To remove the air line from the push-in fitting; pull

outward on the flange of the fitting, push the air line as
far into the fitting as possible and hold, push inward on
the flange, and then pull the air line free of the fitting.

4.3 Connection to the Bulkhead Fitting

c Trim the air line to length using a sharp knife.
c Insert the support spring over the end of the air line - small end first.

(Fig.20.)
c Insert the outer compression nut over the air line.

Figure 19.

Figure 20.

29

4 Installing the Air System

c Insert the 5mm [0.197”] ferrule over the end of the air line. Leave

approx. 5mm of tubing between the ferrule and the end of the tube.
c Insert the support tube all the way into the end of the air line.

HINT : If the support tube is too difficult to insert, place the

end of the air line into a cup of boiled water to soften
the tubing.

c Insert the tube end all the way into the center compression nut.
c Screw on the outer compression nut and tighten. The ferrule and

support tube are now permanently attached.
c Assemble the support spring over the outside of the outer

compression nut.
c Secure any loose sections of tube with a cable tie.

30

5 Mounting & Connecting the Electrical System

5.1 Mounting the Actuator Switch(es)

Air Locker actuator switch(es) can be easily panel mounted inside the
vehicle in a 21mm x 36.5mm [0.83” x 1.44”] rectangular cutout.

NOTE : Only attach the cover plate to the face of the switch once

the switch has been mounted and wired correctly as the
cover plates are designed to be difficult to remove.

For reasons of safety and for ease of operation, the Air Locker actuator
switch(es) should be mounted in a location picked to best suit the
operator. Make sure you have taken the following points into
consideration:

c Switch(es) MUST be mounted and should never be allowed to simply

dangle from the wiring loom during vehicle use.

c Switch(es) should be within easy reach of the driver. Ideally, any Air

Locker switch should be able to be operated without physical effort or

distraction to the driver. Switch(es) should be mounted within the line

of sight of the driver so that switch position (‘ON’ or ‘OFF’) can be

visually determined by the rocker position and the illumination state.
c The position of the switch(es) should best eliminate any possibility of

accidental operation by the driver or one of the passengers.
c Switch cutout position(s) must be located in an area with a minimum

of 50mm [2”] of clearance behind the face of the cutout
c Switch(es) should not be mounted where they will be exposed to

water (e.g., in the lower section of an inner door panel).
c ARB recommends that you apply the Air Locker warning sticker

(ARB part # 210101) within close visual proximity of the switch

location.

Figure 21.

NOTE :
If no adequate position

can be found on existing
dashboard panels, a
surface mounted bracket
(Fig.21.) may be
purchased from your ARB
Air Locker distributor to
suit 1, 2, or 3 switches.

31

5 Mounting & Connecting the Electrical System

IDENTIFICATION

UP

5.2 Wiring the Actuator System

5.2.1 Connection to an ARB Air Compressor

When wiring the Air Locker actuator switch(es) and solenoid(s) to an
ARB Air Compressor, all connections can easily be set up directly from

the supplied wiring loom (Fig.22.).

Refer to your ARB Air Compressor Installation Guide for details
on configuring your installation.

ARB AIR COMPRESSOR WIRING LOOM

Figure 22.

SWITCH

TERMINAL

Figure 23.

32

5 Mounting & Connecting the Electrical System

5.2.2 Connection to an Alternate Air Source

When connecting the actuation switch to an alternate air source, the
switch(es) should be wired according to Figures 24. and 25.,
depending on whether one or two Air Lockers will be installed in the
vehicle.

5.2.2.1 Single Air Locker System

c If only one Air Locker is to be installed in the system, the switch and

solenoid should be wired according to Figure 24. regardless of

whether the Air Locker has been installed in the front or rear axle of

the vehicle.
c Attach the appropriate switch cover (i.e., ‘FRONT’ or ‘REAR’) to the

switch.

NOTE : Refer to Figure 23. for the correct switch terminal

identification and switch orientation.

SINGLE AIR LOCKER SYSTEM

Figure 24.

33

5 Mounting & Connecting the Electrical System

DUAL AIR LOCKER SYSTEM

5.2.2.2 Dual Air Locker System

c If two Air Lockers are to be installed in the system, ARB

recommends that the switches and solenoids be wired according to

Figure 25. For safety reasons, this configuration allows SOLENOID

2 to be actuated only if SOLENOID 1 is already on.
c Attach the “REAR AIR LOCKER” switch cover to SWITCH 1, and

the “FRONT AIR LOCKER” switch cover to SWITCH 2.

NOTE : Refer to Figure 23. for the correct switch terminal

identification and switch orientation.

c Configure SOLENOID 1 as the air line leading to the rear axle Air

Locker, and SOLENOID 2 as the air line leading to the front axle Air

Locker.

Figure 25.

34

6 Testing & Final Assembly

6.1 Leak Testing

c With the vehicle parked and the engine off, turn the compressor on

and wait until the air system is fully charged.

NOTE : With the Air Locker(s) disengaged, the air source (i.e.,

compressor) should not have to recharge over time.
Intermittent recharging without Air Locker use usually
indicates a leak at the solenoid fittings or at the
compressor tank O-ring seal.

c Actuate the Air Locker(s).
c The compressor should not come on again for a period of at least

15min. Air system recharging within that time period would indicate

that a leak is present in the system.

NOTE : If an alternate air source (e.g., an air cylinder or a belt

driven air pump) is used instead of a compressor, the
air system will have to be leak tested with a pressure
gauge and a shut-off valve in series before the
solenoid input.

c If a leak is found to be present, spray a soap and water mixture

onto all air fittings in the system while the compressor is fully

charged. Bubbles should appear at any leak points.

c Check that leaky fittings have been adequately tightened.
c Disassemble, clean threads, and reapply thread sealant if leaking

persists.

6.2 Testing the Air Locker Actuation

To test that your air system, electrical system, and your Air Locker
differential is functioning correctly:

c Support the vehicle such that the wheels are free to rotate (e.g., on

axle stands, a chassis hoist, etc.)

c Leave the parking brake off, the transmission in neutral, and the Air

Locker switch ‘OFF’.

c Turn the ignition to the ‘ON’ position (leaving the motor off). The

large illuminating symbol on the Air Locker switch cover should be

‘OFF’.
c Turn the compressor (or alternate air source) on to charge the air

supply up to its maximum pressure.
c Rotate one wheel by hand.

35

6 Testing & Final Assembly

c The wheel should rotate freely and the opposite wheel should be

turning in the opposite direction without any resistance or

mechanical noise from within the differential.
c Turn the Air Locker switch to the ‘ON’ position. The illuminated

symbol on the switch cover should light up.

c Rotate the same wheel again.
c Both wheels should rotate together.
c Turn the switch off again.
c Rotate the same wheel.
c The wheels should again rotate in opposite directions.

6.3 Re-Sealing & Filling the Differential

NOTE : Consult the ARB Air Locker Operating & Service

Manual for recommendations on differential lubricant
specifications.

c Refill the differential until level with the filler hole.
c Rotate the differential center 2 full turns.
c Check the oil level and refill if necessary.
c Replace filler plug (apply thread sealant to filler plug before

inserting if it is a threaded type plug).
c Wipe differential housing clean of any oil or grease which may

collect dirt or other abrasive particles.

6.4 Note For ADD Equipped Vehicles

IFS vehicles equipped with Automatic Differential Disconnect (ADD)
do not disconnect both wheels from the differential. Because of this,
the internal gears of the differential of all ADD vehicles are in
constant motion when moving in two wheel drive. For this reason,
the front Air Locker in an ADD equipped vehicle must never be
engaged while moving in two wheel drive, as doing so would
cause any motion in the internal differential gears to be instantly
transferred to your ring and pinion set, potentially causing extensive
damage to your ring and pinion gears, your CV joints, and to your
Air Locker differential. To eliminate this problem, save wear on your
differential components, prolong the life of your CV joints, and
increase your fuel mileage, ARB recommends that you eliminate the
drag and wear in your front driveline components (which are not
even being used in 2WD) by installing manual locking hubs,
especially if your vehicle is used for extensive two wheel driving.

36

6 Testing & Final Assembly

6.5 Post-Installation Check List

Now that the Air Locker installation has been completed, ARB
recommends that you take the time to complete the following check list
just to insure that you haven’t missed any of the vital steps.

c The air system has been leak tested.
c Thread locking compound was used on the ring gear bolts.
c All torque settings comply with the vehicle manufacturer’s specs

and were set with an accurate torque wrench.
c Differential fluid complies with ARB recommendations and has

been filled to the correct level.
c All air lines and wiring have been securely cable tied to resist

snagging.
c Switch(es) have been securely mounted within operator reach, yet

well away from danger of accidental engagement.

c Switch(es) function correctly and illuminate to indicate that Air

Locker(s) have been engaged.

c The Air Locker Warning Sticker has been located within close

proximity of the actuator switch(es).
c All operators who are to use the Air Locker have read, and fully

understand the ARB Air Locker Operating & Service Manual.

INSTALLATION PERFORMED BY:

DATE OF INSTALLATION:

ODOMETER READING:

___________________________
___________________________
___________________________

AIR LOCKER SERIAL No.:

37

___________________________

6 Testing & Final Assembly

38

7 Parts List

7.1 Exploded Assembly Diagram (see itemized parts list overleaf)

Figure 26.

39

7 Parts List

7.2 Itemized Parts List

(see exploded diagram Fig.26. )

AIR LOCKER MODEL No. : RD110

ITEM # QTY DESCRIPTION PART #

1 1 BONDED SEAL 160701
2 1 CLUTCH GEAR 050802
3 8 RETURN SPRING 150113
4 1 LONG CROSS SHAFT 061302
5 1 SPIDER BLOCK 070503
6 1 DIFFERENTIAL CASE 013107
7 3 CROSS SHAFT RETAINING PIN 120601
8 --- TAPERED ROLLER BEARING

9 1 SHIM KIT SHK002
10 1 TAPERED ROLLER BEARING 160117
11 1 SEAL HOUSING ASSEMBLY 081701
12 2 SEAL HOUSING O-RING 160233
13 1 FLANGE CAP ASSEMBLY 028507
14 1 LOCKING SIDE GEAR 131605H
15 4 PINION THRUST WASHER 151112
16 4 PINION GEAR 140801H
17 2 SHORT CROSS SHAFT 061402
18 1 SIDE GEAR 131505H
19 2 SIDE GEAR THRUST WASHER 151011
20 2 CSK SCREW 200213
21 1 ANTI-FRICTION BUSHING (PTFE) 160803

* 1 NYLON AIR LINE (5mm Dia X 6m long) 170301
* 1 BULKHEAD KIT, 3.5mm O-RING TYPE 170105
* 1 PUSH-IN FITTING,5mm (R1 5 1/8”) 170201
* 1 SOLENOID VALVE (12V) 180103
* 10 CABLE TIE 180301
* 1 NIPPLE, 1/8” BSP, MALE TO MALE 170501
* 1 ACTUATOR SWITCH 180209
* 1 SWITCH COVER (FRONT) 180210
* 1 BUMPER STICKER 210102
* 1 WARNING STICKER 210101
* 1 OPERATING & SERVICE MANUAL 210200
* 1 INSTALLATION GUIDE 2102110

NOT SUPPLIED

Not illustrated in exploded view.

*

40