ARB RD93 User Manual

INSTALLATION GUIDE

CHRYSLER 8

Copyright © 2001 by ARB Corporation Limited

RD93

1

/4”, 29 SPLINE

Part No. 210293

Revision Date 06/02/07

No liability is assumed for damages resulting in the use of the information contained herein.
ARB AIR LOCKER 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 Axles 5

2.4 Marking the Bearing Caps 6

2.5 Checking the Current Backlash Amount 7

2.6 Removing the Differential Carrier 8

3 Installing the Air Locker 10

3.1 Mounting the Ring Gear 10

3.2 Installing the Carrier Bearings 11

3.3 Drilling and Tapping the Bulkhead Port 12

3.4 Setting the Backlash 13

3.5 Profiling the Seal Housing Tube 14

3.6 Setting up the Bulkhead Fitting 16

3.7 Re-Installing the Axles 18

4 Installing the Air System 19

4.1 Mounting the Solenoid 19

4.2 Running & Securing the Air Line 21

4.3 Connection to the Bulkhead Fitting 22

5 Mounting & Connecting the Electrical System 23

5.1 Mounting the Actuator Switch(es) 23

5.2 Wiring the Actuator System 24

6 Testing & Final Assembly 27

6.1 Leak Testing 27

6.2 Testing the Air Locker Actuation 27

6.3 Re-Sealing & Filling the Differential 28

6.4 Post-Installation Check List 29

7 Parts List 31

7.1 Exploded Assembly Diagram 31

7.2 Itemized Parts List 32

1

2

2 Removing the Existing Differential

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  symbols as

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

3

2 Removing the Existing Differential

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

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

wrenches, Allan keys, and drills.

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

pinion backlash.

 A razor knife for nylon tubing.
 A suitable adjuster nut wrench to set backlash and preload for your

model of axle assembly.

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

range)

 A lubricant drain reservoir.
 A 11.2mm [7/16”] drill and ¼”NPT tap for bulkhead fitting installation.
 Needle-nosed pliers.
 An automotive bearing puller (2 jawed) or a differential carrier bearing

puller.

 A bearing press or arbor press.

1.2.2 Supplies

 Thread lubricant/sealant compound (e.g., LOCTITE #567)
 Thread locking compound (e.g., LOCTITE #272)
 A gasket sealant or replacement gasket for your differential cover.
 A sufficient volume of differential oil to completely refill your housing.

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

 A soap and water mixture to test for air leaks.
 Teflon paste.

4

2 Removing the Existing Differential

2.1 Vehicle Support

 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.

 Once supported in the air, release the parking brake and leave the

vehicle in neutral. Chock the wheels if necessary.

2.2 Differential Fluid Drain

 Clean around the differential cover seal to prevent dirt from entering

the differential.

 Position a fluid drain reservoir under the differential.
 If a drain plug exists, remove it and completely drain all differential oil

from the housing.

 If no drain plug exists then the oil can be drained by loosening the

cover bolts and gently prying the cover away at the bottom until oil
runs out.

HINT : If no drain plug exists then it would be a good idea to drill

and tap for a tapered oil drain plug to assist with future oil
changes.

 Once drained, remove the differential cover plate.

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

your oil and in the bottom of the housing which may
indicate a worn bearing or differential component.

2.3 Removing the Axles

IMPORTANT :

Collision damage or heavy off-road use of your vehicle in the past

may have resulted in some degree of bending in the axle. Any

misalignment of the axle tubes may result in excessive wear and/or

failure of your differential and axle shafts. ARB strongly

recommends that you have your axle assembly inspected for

concentricity and straightness before installing your Air Locker.

5

2 Removing the Existing Differential

 Remove the wheels and brake assembly according to your vehicle’s

service manual.

 Rotate the differential center until the cross shaft can be removed.
 Remove the cross shaft retaining pin and the cross shaft.
 Rotate the differential until the ‘C’ clip access window is accessible.
 Gently tap the axle ends inward to release the ‘C’ clips.
 Remove ‘C’ clips with needle nose pliers.
 Gently tap axles outward and remove them from the differential center.

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

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

2.4 Marking the Bearing Caps

 Using a small pointed center punch, gently mark the left bearing cap in

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

 Mark the right hand cap in a similar way.

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.

Figure 1.

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 after market 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.

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

Figure 2.

 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.

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

7

2 Removing the Existing Differential

2.6 Removing the Differential Carrier

 Remove the adjuster nut locking tabs.
 Remove the bearing caps from the third member.
 Remove the adjuster nuts.
 Carefully remove the differential carrier from the third member.

NOTE : The differential center is heavy and quite difficult to

handle when covered in oil. Do not drop it!

 Remove the tapered roller bearings from the differential carrier with a

bearing puller. (Fig.3.)

HINT : Check the condition of the bearing for wear and discard

if damaged.

Figure 3.

 Secure the original differential to a work bench.
 Remove the bolts that hold the ring gear in place.

NOTE : Chrysler 8.25” ring gear bolts are usually left hand

threaded.

 Using a plastic or copper hammer, tap in a circle around the ring gear

to separate it from the differential carrier.

8

2 Removing the Existing Differential

IMPORTANT:

Some Salisbury axles were manufactured with poor oil drainage

between the axle tubes and the differential housing. This can often

result in one of the axle tubes filling up with differential oil while

running. In most cases this will result in a blocked air vent which

will cause the differential housing to pressurize and expel oil from

the axle seals at the wheels or force oil into the air system of the Air

Locker, eventually expelling oil at the solenoid valve. This is a

design flaw which was corrected by most automakers in the later

releases of their axle assemblies. If no lower drainage point is

present in the differential housing then it is critical that you modify

the housing to include one.

 Inspect the differential housing for the presence of adequate drainage

in both axle tubes (refer to Fig.4.).

Figure 4.

 If drainage is inadequate or does not exist then a slot or hole should

be cut into the housing on the lower side of the tube(s) to allow oil out
of the axle tube area.

NOTE : Make sure any grinding dust, filings or drill chips left

behind by cutting the drainage slots is completely
cleaned out of the housing.

 Check that the axle air vents are clear and working correctly.

9

3 Installing the Air Locker

3.1 Mounting the Ring Gear

IMPORTANT:

Higher ratio gearing uses deeper (thicker) ring gears with teeth

that extend much further. Make sure the teeth of the ring gear will

not obstruct the removal of the cross shaft when fitted. If so,

ARB recommends that you grind just enough off of one of the

ring gear teeth to successfully remove the cross shaft.

DO NOT MODIFY THE CROSS SHAFT!

IMPORTANT:

Newer OEM Chrysler 8.25” ring and pinion sets use 7/16” bolts.

The flange holes of the Air Locker must be reamed from

Ø3/8” to Ø7/16” to suit.

NOTE : If your existing differential was fitted with a toner

ring it will need to be removed and installed onto the
Air Locker before the ring gear can be mounted.
See your vehicle service manual.

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

of the Air Locker to prevent seizing.

 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.

 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.

 Dry the gear and bolt holes with compressed air (if wet).
 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.

10

3 Installing the Air Locker

 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.

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

according to your vehicle manufacturer’s specified torque

3.2 Installing the Carrier Bearings

 Apply a thin film of high pressure grease to the bearing journal of

the Air Locker.

 Using a bearing press or arbor press, press one of the bearing

cones which was removed from the original differential onto the
bearing journal (refer to Figure 5.) until the bearing seats firmly
against the bearing journal shoulder.

.

Figure 5.

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

worn.
Do not bend or damage the seal housing tube.

11

3 Installing the Air Locker

3.3 Drilling and Tapping the Bulkhead Port

An airline port must be drilled and tapped through the differential
housing to mount the bulkhead fitting into.

 Mark a spot on the top of the outside shell of the differential

housing that will be clear of the ring gear position once the seal
housing tube has been installed. Figure 6. shows how the tube will
port through the differential housing.

NOTE : Higher ratio gearing uses deeper (thicker) ring gears

with teeth that extend much further. Make sure the
intended hole location is far enough away from the
ring gear teeth that the air line will not be at risk of
contact with the current or future ring gears.

Figure 6.

 Cover the drive pinion and axle tube areas with a rag to protect

them from metal filings.

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

11.2mm [7/16”] drill. (Figure 7.)

Figure 7.

12

3 Installing the Air Locker

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

into the housing.

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

housing to insure no metal filings are left behind.

3.4 Setting the Backlash

 Hold the bearing cups onto the Air Locker, insert it into the housing

and rotate it until it is fully in mesh with the pinion gear.

 Sit the adjuster nuts into the threads against the bearing cups.
 Install the bearing caps (use the markings from Section 2.4 to

determine which side is which) and hand tighten all bearing cap
bolts lightly.

 Hand tighten both adjuster nuts against the Air Locker until only a

small amount of backlash can be felt.

 Set a depth indicator on one of the ring gear teeth as in

Figure 8.

 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.

 Rotate the differential center 90° and measure again for accuracy.

Figure 8.

13

3 Installing the Air Locker

 Refer to your vehicle service manual for the specified maximum

and minimum amounts of backlash.

 Adjust the backlash using an adjuster nut wrench to tighten or

loosen the adjuster nuts as required.
(Refer to your vehicle service manual.)

 Recheck backlash as before, repeating this procedure until

backlash is within the specified amount.

IMPORTANT:

It is critical to set up bearing pre-load when a differential is

installed. 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.

 Set pre-load by tightening the adjuster nuts against each other by

an amount specified in your vehicle service manual.

 Tighten the bearing cap bolts with a torque wrench to the torque

specified in your vehicle manufacturer’s service manual.

 Install locking tabs onto the bearing caps.

3.5 Profiling the Seal Housing Tube

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

hands are the best tool for this job), bend the seal housing tube so
that it runs under the ring gear and upwards protruding through the
bulkhead port in the differential housing. (Fig. 9. & Fig. 10.)

 Check that the contour of the tube will not interfere with the Air

Locker or the ring gear.

NOTE : It is a good idea to keep the tube away from the

bearing caps or any other part of the differential
casting as any contact due to vibration or shock may
wear the tube and eventually cause a leak.

14

3 Installing the Air Locker

Figure 9.

Figure 10.

15

3 Installing the Air Locker

3.6 Setting up the Bulkhead Fitting

 Trim the seal housing tube that is extended outside the differential

housing to approximately 20-25mm [0.8-1.0”] of extension using an
automotive brake line tubing cutter.

NOTE : Never use a hacksaw for trimming the steel tube as

this will leave metal fillings in the air system.

 Apply thread sealant to the threads of the bulkhead body.
 Screw the bulkhead body into the tapped hole, and tighten.
 Wipe the area clean of any excess thread sealant (inside and

outside of the housing).

 From the outside of the housing, assemble the small O-ring over

the top of the short length of seal housing tube protruding through
the bulkhead fitting.

 While holding the seal housing tube into the bulkhead fitting, insert

the small drilled end of the center compression nut over the
extended tube as shown in the assembly diagram (Fig. 11.), and
screw it into the bulkhead body, and lightly tighten.

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. 11.)

16

3 Installing the Air Locker

Figure 11.

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, the seal housing tube, or
the threads of the compression nut.

NOTE : Make sure the seal housing tube is all of the way into

the center compression nut while you are tightening
it.

 Again check that no part of the seal housing tube comes in contact

with the moving differential components. Less than 8mm [5/16”]
should be considered too little clearance. Gently bend the tube
away from moving parts if necessary.

17

3 Installing the Air Locker

3.7 Reinstalling the Axles

 Unscrew and remove the long cross shaft retaining pin with a 5mm

hex key.

NOTE : The long cross shaft retaining pin is the pin located

exactly one quarter turn of the differential from the ‘C’
clip access window. Rotate the differential using the
drive flange.

Figure 12.

 Completely remove the long cross shaft.
 Rotate the differential center until the ‘C’ clip access window in the

differential is in view and accessible.

 Insert both axles fully into the housing and gently tap them inward.
NOTE : Be careful not to damage oil seals with the axle.

 Install the ‘C’ clips on to the ends of the axles.
 Gently tap the axles outward until both ‘C’ clips are fully seated.
 Insert the cross shaft maintaining alignment between the cross

shaft retaining pin hole in the differential and its corresponding hole
in the cross shaft.

 Ensure that some degree of axle end float exists (i.e., some

clearance exists between the end of the axle and the cross shaft or
thrust block). ‘C’ clips may need to be substituted with others of a
different thickness to achieve correct end float if too tight or too
loose. Refer to your vehicle manufacturer’s service manual for the
procedure on setting up the correct end float condition.

 Insert and tighten the pin with a 5mm hex key.
 Reassemble brakes and wheels according to your vehicle’s service

manual.

18

4 Installing the Air System

4.1 Mounting the Solenoid

4.1.1 Connection to an ARB Air Compressor (Fig.13.)

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

tank.

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

the port and tighten.

 Apply Teflon paste to the free end of the nipple.
 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.

 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 13.

19

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:

 Must supply a minimum of 85PSI [586kPa].
 The supply must never exceed 105PSI [724kPa].
 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).

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

matter.

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

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

from the effects of vibration and shock.

 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.

20

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:

 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.

 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

 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.

line from getting snagged.

 Make sure the line does not contact sharp edges or abrasive

surfaces that may damage the air line over time.

 Do not run the air line around tight bends which may kink the air line

and restrict or block the air flow.

 Keep the air line well away from your vehicle’s exhaust components.

Air lines will melt if subjected to extreme heat.

 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.

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

knife.

 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.

21

4 Installing the Air System

4.3 Connection to the Bulkhead Fitting

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

(Fig.15.)

 Insert the outer compression nut over the air line.

Figure 14.

Figure 15.

 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.

 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.

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

support tube are now permanently attached.

 Assemble the support spring over the outside of the outer

compression nut.

 Secure any loose sections of tube with a cable tie.

22

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:

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

dangle from the wiring loom during vehicle use.

 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.

 The position of the switch(es) should best eliminate any possibility of

accidental operation by the driver or one of the passengers.

 Switch cutout position(s) must be located in an area with a minimum

of 50mm [2”] of clearance behind the face of the cutout

 Switch(es) should not be mounted where they will be exposed to

water (e.g., in the lower section of an inner door panel).

 ARB recommends that you apply the Air Locker warning sticker

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

Figure 16.

NOTE :
If no adequate position

can be found on existing
dashboard panels, a
surface mounted bracket
(Fig. 16.) may be
purchased from your ARB
Air Locker distributor to
suit 1, 2, or 3 switches.

23

5 Mounting & Connecting the Electrical System

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.17.).

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

ARB AIR COMPRESSOR WIRING LOOM

SWITCH

IDENTIFICATION

TERMINAL

Figure 18.

Figure 17.

UP

24

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 19. and 20.,
depending on whether one or two Air Lockers will be installed in the
vehicle.

5.2.2.1 Single Air Locker System

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

solenoid should be wired according to Figure 19. regardless of
whether the Air Locker has been installed in the front or rear axle of
the vehicle.

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

switch.

NOTE : Refer to Figure 18. for the correct switch terminal

identification and switch orientation.

SINGLE AIR LOCKER SYSTEM

Figure 19.

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5 Mounting & Connecting the Electrical System

5.2.2.2 Dual Air Locker System

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

recommends that the switches and solenoids be wired according to
Figure 20. For safety reasons, this configuration allows SOLENOID
2 to be actuated only if SOLENOID 1 is already on.

 Attach the “REAR AIR LOCKER” switch cover to SWITCH 1, and

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

NOTE : Refer to Figure 18. for the correct switch terminal

identification and switch orientation.

 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.

DUAL AIR LOCKER SYSTEM

Figure 20.

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6 Testing & Final Assembly

6.1 Leak Testing

 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.

 Actuate the Air Locker(s).
 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.

 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.

 Check that leaky fittings have been adequately tightened.
 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:

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

axle stands, a chassis hoist, etc.)

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

Locker switch ‘OFF’.

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6 Testing & Final Assembly

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

large illuminating symbol on the Air Locker switch cover should be
‘OFF’.

 Turn the compressor (or alternate air source) on to charge the air

supply up to its maximum pressure.

 Rotate one wheel by hand.
 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.

 Turn the Air Locker switch to the ‘ON’ position. The illuminated

symbol on the switch cover should light up.

 Rotate the same wheel again.
 Both wheels should rotate together.
 Turn the switch off again.
 Rotate the same wheel.
 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.

 Replace the differential cover using gasket sealant or a standard

differential cover gasket for your make of vehicle.

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

inserting if it is a threaded type plug).

 Wipe differential housing clean of any oil or grease which may

collect dirt or other abrasive particles.

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6 Testing & Final Assembly

6.4 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.

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

and were set with an accurate torque wrench.

 Differential fluid complies with ARB recommendations and has

been filled to the correct level.

 All air lines and wiring have been securely cable tied to resist

snagging.

 Switch(es) have been securely mounted within operator reach, yet

well away from danger of accidental engagement.

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

Locker(s) have been engaged.

 The Air Locker Warning Sticker has been located within close

proximity of the actuator switch(es).

 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.:

29

___________________________

6 Testing & Final Assembly

30

7 Parts List

7.1 Exploded Assembly Diagram (see itemized parts list overleaf)

Figure 21.

31

7 Parts List

7.2 Itemized Parts List

(see exploded diagram Fig. 21. )

AIR LOCKER MODEL No. : RD93

ITEM # QTY DESCRIPTION PART #

1 1 SEAL HOUSING ASSEMBLY 081501
2 1 CLUTCH GEAR 050801
3 3 PINION THRUST WASHER 151110
4 3 PINION GEAR 140701R
5 1 LONG CROSS SHAFT 060204
6 1 SHORT CROSS SHAFT 060403
7 1 DIFFERENTIAL CASE 013002
8 2 CSK SCREW 200213

9 2 CROSS SHAFT RETAINING PIN 120601
10 1 TAPERED ROLLER BEARING 160109
11 2 O-RING, SEAL HOUSING 160227
12 1 FLANGE CAP ASSEMBLY 028402
13 1 BONDED SEAL 160702
14 8 RETURN SPRING 150107
15 1 LOCKING SIDE GEAR 131402R
16 1 SPIDER BLOCK 070301
17 1 SIDE GEAR 131302R
18 2 SIDE GEAR THRUST WASHER 151010
19 --- TAPERED ROLLER BEARING

* 1 C-CLIP KIT CCK005
* 1 NYLON AIR LINE (5mm Dia X 6m long) 170301
* 1 BULKHEAD KIT, O-RING TYPE, 3.5-5mm 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 (REAR) 180211
* 1 BUMPER STICKER 210102
* 1 WARNING STICKER 210101
* 1 OPERATING & SERVICE MANUAL 210200
* 1 INSTALLATION GUIDE 210293

NOT SUPPLIED

Not illustrated in exploded view.

*

32