ARB RD115 User Manual

RD

115

DANA 70HD, 3

7

SPLINE, 4.56 & UP

INSTALLATION GUIDE

Part No. 2102115

Revision Date 15/01/04

Copyright © 2004 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 enquiries [e-mail]
North and 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

2 Removing the Existing Differential 5

3 Bench Measurement 9

4 Installing the Air Locker 12

4.10

4.11

4.12

5 Installing the Air System 27

6 Mounting & Connecting the Electrical System 32

7 Testing & Final Assembly 37

8 Parts List 41

Tool-Kit Recommendations 4

2.1

Vehicle Support 5

2.2

Differential Fluid Drain 5

2.3

Removing the Axle 5

2.4

Marking the Bearing Caps 6

2.5

Checking the Current Backlash Amount 7

2.6

Spreading the Differential Housing 8

3.1

Measurement for Pre-Load Shimming 9

3.2

Calculation & Selection of Shims 11

4.1

Installing the Carrier Bearings 12

4.2

Mounting the Ring Gear 13

4.3

Drilling & Tapping the Bulkhead Port 14

4.4

Assembling the Differential Carrier 15

4.5

Approximating the Backlash for Tube Position 16

4.6

Marking the Bearing Cap for Tube Clearance 18

4.7

Modifying the Bearing Cap 20

4.8

Final Air Locker Assembly 22

4.9

Final Backlash Checking 22
Profiling the Seal Housing Tube 24
Setting up the Bulkhead Fitting 25
Reinstalling the Axles 26

5.1

Mounting the Solenoid 27

5.2

Running & Securing the Air Line 29

5.3

Connection to the Bulkhead Fitting 30

6.1

Mounting the Actuator Switch(es) 32

6.2

Wiring the Actuator System 33

7.1

Leak Testing 37

7.2

Testing the Air Locker Actuation 37

7.3

Re-Sealing & Filling the Differential 38

7.4

Post-Installation Check List 39

8.1

Exploded Assembly Diagram 41

8.2

Itemized Parts List 42

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 Automotive brake tubing cutters to cut the steel tubing.
c A razor knife to cut the nylon tubing.
c A differential housing spreader, to facilitate removal of the carrier.
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 cover plate seal to prevent dirt from

entering the differential.

c Position a fluid drain reservoir under the differential and loosen all

differential cover plate retaining bolts.

c Gently pry the cover plate away from the differential housing to

completely drain all differential fluid.

c Once drained, remove 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

c Remove the backing plate nuts from the axle housing.
c Discard the nuts and replace at time of reassembly.

NOTE : The nuts are designed to be tightened only once and

must not be reused.

c Remove each axle shaft by pulling outward on the axle. It may

need to be loosened with pry bars.

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

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 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, 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 Spreading the Differential Housing

IMPORTANT:

Spreading the differential housing with a differential case

spreader is a step which 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.

c Unbolt and remove the bearing caps from the differential housing.

HINT : Be sure not to mix up the left and right hand bearing

caps. Later it will be necessary to know which cup
came from which bearing and which shim came from
which side.

c Carefully spread the housing (Fig. 3.) enough to remove the

differential center. (Refer to your vehicle’s service manual).

NOTE : Do not spread the housing more than 0.50mm

[0.020”].

c Once the housing has been adequately spread, the differential may

be removed by pulling forward on the differential carrier.

Figure 3.

NOTE : The differential center is heavy and quite difficult to

handle when covered in oil. Take care not to drop it.

8

3 Bench Measurement

3.1 Measurement for Pre-Load Shimming

When fitting an ARB Air Locker, a replacement bearing and variable
shim pack (supplied) are used on the right hand side (opposite the ring
gear) in order to achieve the correct ring and pinion backlash and
carrier bearing pre-load once the Air Locker has been installed.
Because of this, the original shims and bearing from this side will not
be reused.

The original bearing type and shim type are used on the left hand (ring
gear) side 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 this side.

c Secure the differential to a work bench.
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 carrier

using a bearing puller.

NOTE : Keep the shims separated so that they can be

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

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 bearing shoulder to the ring gear
mounting face (shown as ‘A’ in Figure 4.) and record this
measurement as ‘A’.

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’.

9

3 Bench Measurement

Figure 4.

Figure 5.

10

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 which are damaged or worn.

11

4 Installing the Air Locker

4.1 Installing the Carrier Bearings

c With the Air Locker well supported in an arbor press, apply a thin

film of high pressure grease to the ring gear side bearing journal,
and assemble the newly established shim pack onto the bearing
journal.

c Press the tapered roller bearing cone onto the bearing journal of

the differential carrier until the bearing seats firmly against the shim
pack.

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

worn.

c Invert the Air Locker and apply a thin film of high pressure grease

to the seal housing side bearing journal.

c Press the bearing cone which was supplied with the Air Locker kit

onto the bearing journal, taking care not to damage the o-ring
grooves. (Figure 6.)

Figure 6.

NOTE : Do not add any shims between the seal housing

bearing and the bearing seat.

12