ARB RD94 User Manual

RD94

INSTALLATION GUIDE

ISUZU IFS, 17 SPLINE

Part No. 210294

Revision Date 11/11/03

Copyright © 2002 by ARB Corporation Limited

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 enquires [e-mail]
North and South American enquires [e-mail]
Other international enquires [e-mail]

www.arb.com.au

1 Introduction 3

1.1

Pre-Installation Preparation 3

1.2

2 Removing the Existing Differential 5

3 Bench Measurement 8

4 Installing the Air Locker 11

4.10

4.11

5 Installing the Air System 25

6 Mounting & Connecting the Electrical System 29

7 Testing & Final Assembly 34

8 Parts List 37

Tool-Kit Recommendations 4

2.1

Vehicle Support 5

2.2

Differential Fluid Drain 5

2.3

Removal of Axles and Differential 5

2.4

Marking the Bearing Caps 6

2.5

Checking the Current Backlash Amount 7

2.6

Removing the Differential Carrier 7

3.1

Measurement for Pre-Load Shimming 8

3.2

Calculation & Selection of Shims 10

4.1

Installing the Carrier Bearings 11

4.2

Mounting the Ring Gear 12

4.3

Drilling & Tapping the Bulkhead Port 13

4.4

Assembling the Differential Carrier 14

4.5

Modifying the Bearing Cap 16

4.6

Final Air Locker Assembly 17

4.7

Final Backlash Checking 18

4.8

Profiling the Seal Housing Tube 19

4.9

Setting up the Bulkhead Fitting 21
Bench Testing the Air Locker 23
Reinstalling the Axles 24

5.1

Mounting the Solenoid 25

5.2

Running & Securing the Air Line 27

5.3

Connection to the Bulkhead Fitting 28

6.1

Mounting the Actuator Switch(es) 29

6.2

Wiring the Actuator System 30

7.1

Leak Testing 34

7.2

Testing the Air Locker Actuation 34

7.3

Filling the Differential 35

7.4

Post-Installation Check List 36

8.1

Exploded Assembly Diagram 37

8.2

Itemized Parts List 38

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, Alan keys, and drills.

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

pinion backlash.

c A standard automotive feeler gauge.
c A razor knife to cut the nylon tubing.
c A torque wrench. (See vehicle service manual for required torque

range.)

c A lubricant drain reservoir.
c Suitable measuring tools to measure a differential for pre-load

and/or backlash shimming. (See Section 3 Bench Measurement)

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

installation.

c An automotive bearing puller (2 jawed is recommended) or a

differential carrier bearing puller.

c A bearing press or arbor press.

1.2.2 Supplies

c Thread lubricant/sealant compound (e.g., LOCTITE #567)
c Thread locking compound (e.g., LOCTITE #272)
c Either a replacement gasket, or gasket sealant, for your differential

cover.

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 Teflon paste.
c A selection of differential bearing shims to set-up pre-load and

backlash. (See section 3 Bench Measurement)

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 off the ground, release the parking brake and

leave the vehicle in neutral. Chock the wheels if necessary.

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 and loosen the

differential drain plug.

c Completely drain all differential fluid.

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 Removal of the Axles and Differential

c Remove the front wheels from the vehicle.
c Disconnect the drive shaft from the flange of the differential.
c Remove the front axle assembly according to your vehicle

manufacturer service manual.

HINT : By removing the CV retaining clip from the left hand

hub assembly, removing the front right hand side
spindle/knuckle assembly and separating the mounting
bracket from the CV on the right hand side, it may be
possible to remove the front axle assembly without
removing the control arms.

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

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

c Remove the differential housing from the axle case and secure it to

a workbench.

5

2 Removing the Existing Differential

2.4 Marking the Bearing Caps

c Using a 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.)

HINT : Many installers choose to make one punch mark on

the left hand side of the left hand bearing cap and one
similar punch 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 authorised ARB

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

installer for more information.

Figure 2.

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.

2.6 Removing the Differential Carrier

c Remove the bearing caps from the differential housing.
c Carefully remove the differential carrier from the differential

housing.

7

3 Bench Measurement

3.1 Measurement for Pre-Load Shimming

When fitting an ARB Air Locker, the original bearing types are used on
both sides of the Air Locker, however, in order to reproduce a similar
backlash and pre-load to that of your existing differential,
measurements need to be taken so that the correct shim thickness
can be determined for each side.

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 tapered roller bearings and shims from the

differential carrier using a bearing puller. (Fig 3.)

NOTE : Keep the shims separated so that they can be

identified as to which end of the differential they came
from.

Figure 3.

HINT : Check the condition of the bearing for wear and

replace if necessary.

c Using a calliper or similarly accurate measurement method

(i.e., able to take accurate measurements within 0.04mm [0.0015”]),
measure the distance from the bearing shoulder to the ring gear
mounting face (shown as ‘A’ in Figure 4.) and record this
measurement as ‘A’.

8

3 Bench Measurement

c Measure the thickness of the shim pack removed from the ring gear

side of the differential carrier (shown as ‘B’ in Figure 4.).and record
this measurement as ‘B’.

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

ring gear mounting face (shown as ‘C’ in Figure 5.) and record this
measurement as ‘C’.

Figure 4.

Figure 5.

9

3 Bench Measurement

3.2 Calculation & Selection of Shims

The thickness of the shim pack required for the Air Locker (shown as
‘D’ in Figure 5.) can now be determined by substituting the
measurements taken into the following equation.

A + B – C = D

HINT : If your calculations are correct then the following

equation will also be true:

A + B – C – D = ZERO

To make a shim pack to match the measurement you calculated as ‘D’
you can:

§ remove shims from the shim pack you measured as ‘B’.

§ add some shims from the shim pack you removed from the right

hand side of the original differential to the shim pack you
measured as ‘B’.

§ supplement your original shims with shims purchased from your
vehicle manufacturer.

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

NOTE : Never re-use any shims that are damaged or worn.

10