ARB RD129 User Manual

RD129

TOYOTA TACOMA/TUNDRA

Part No. 2102129

Revision Date 22/02/07

Copyright © 2007 by ARB Corporation Limited

INSTALLATION GUIDE

REAR,30 SPL

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 23

6 Mounting & Connecting the Electrical System 27

7 Testing & Final Assembly 32

8 Parts List 35

Tool-Kit Recommendations 4

2.1

Vehicle Support 5

2.2

Differential Fluid Drain 5

2.3

Removing the Axles and Differential 5

2.4

Marking the Bearing Caps 6

2.5

Checking the Current Backlash Amount 6

2.6

Spreading the Differential Housing 8

3.1

Approximate Backlash Shimming 9

3.2

Calculation & Selection of Shims 11

4.1

Installing the Carrier Bearings 12

4.2

Mounting the Ring Gear 12

4.3

Assembling the Seal Housing 13

4.4

Calculation & Selection of Pre-Load Shims 14

4.5

Drilling and Tapping the Bulkhead Port 15

4.6

Modifying the Bearing Cap 16

4.7

Final Air Locker Assembly 17

4.8

Final Backlash Checking 18

4.9

Profiling the Seal Housing Tube 19
Setting up the Bulkhead Fitting 19
Bench Testing the Air Locker 21
Reinstalling the Differential and Axles 22

5.1

Mounting the Solenoid 23

5.2

Running & Securing the Air Line 25

5.3

Connection to the Bulkhead Fitting 26

6.1

Mounting the Actuator Switch(es) 27

6.2

Wiring the Actuator System 28

7.1

Leak Testing 32

7.2

Testing the Air Locker Actuation 32

7.3

Filling the Differential 33

7.4

Post-Installation Check List 34

8.1

Exploded Assembly Diagram 35

8.2

Itemized Parts List 36

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, Allen 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 copper 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 for pressure fittings (e.g.,

LOCTITE #567 Teflon paste)

c Thread locking compound (e.g., LOCTITE #272)
c Either a replacement gasket, or gasket sealant.
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 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 third member flange seal to prevent dirt from

entering the differential.

c Position a fluid drain reservoir under the differential.
c Remove fluid drain plug to empty all differential oil.

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

your oil which may indicate a worn bearing or
differential component.

2.3 Removing the Axles and Differential

c Remove the axles according to your vehicle’s service manual.
c Disconnect the drive shaft from the flange of the differential.
c Remove the third member from the differential housing. (Refer to

your vehicle’s service manual)

NOTE : The differential housing is heavy and quite difficult to

handle when covered in oil. Do not drop it!

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 differential housing

and the bearing caps in a way that will enable you to correctly
position the cap during reassembly. (Fig.1.)

Figure 1.

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.

6

2 Removing the Existing Differential

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.
c Setup the differential spreader and a dial indicator and carefully

spread the differential housing (Fig.3.) just enough to remove the
differential carrier (Refer to your vehicle’s service manual).

NOTE : Never spread the housing more than 0.5mm [0.020”].
c Once the housing has been adequately spread, the differential may

be removed by pulling forward on the differential center.

c Remove spreader tension.

Figure 3.

8

3 Bench Measurement

3.1 Approximate Backlash Shimming

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

c Secure the original 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 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
they came from.

c Examine the bearing cups and cones from Fig. 4. for damage or

wear and, if necessary, discard them and replace with the same
size and type of bearings.

Figure 4.

9

3 Bench Measurement

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 Fig.4.) 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 Fig.4.) and record this
measurement as ‘B’.

Figure 5.

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

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

10