Airlocker RD219 User manual

RD219
T6 RANGER/BT50, IFS, 29 SPL
AIR OPERATED
LOCKING DIFFERENTIAL
INSTALLATION GUIDE

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
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
Checking the Current Backlash Amount
6
2.5
Removing the Differential Center
7
3 Installing the Air Locker
8
3.1
Approximate Backlash Shimming
8
3.2
Calculation & Selection of Backlash Shims
10
3.3
Mounting the Ring Gear
11
3.4
Installing the Carrier Bearings
12
3.5
Preload Shim Measurement
13
3.6
Calculation & Selection of Preload Shims
15
3.7
Drilling & Tapping the Bulkhead Port
15
3.8
Installing the Seal Housing
17
3.9
Installing the Bulkhead Fitting
19
3.10
Setting Up the Bulkhead Fitting
19
3.11
Final Assembly
20
3.12
Checking the Backlash
21
3.13
Bench Testing the Air Locker
23
3.14
Reinstalling the Differential Assembly
24
4 Installing the Air System
25
4.1
Mounting the Solenoid
25
4.2
Running & Securing the Air Line
27
4.3
Connection to the Bulkhead Fitting
28
5 Mounting & Connecting the Electrical System
29
5.1
Mounting the Actuator Switch(es)
29
5.2
Wiring the Actuator System
30
6 Testing & Final Assembly
33
6.1
Leak Testing
33
6.2
Testing the Air Locker Actuation
33
6.3
Re-Sealing & Filling the Differential
34
6.4
Post-Installation Check List
35
7 Parts List
37
7.1
Exploded Assembly Diagram
37
7.2
Itemized Parts List
38

2

2 Removing the Existing Differential
3
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!

2 Removing the Existing Differential
4
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 torque wrench (See vehicle service manual for required torque
range).

A lubricant drain reservoir.

A slide hammer for removing CV axles.

Suitable measuring tools to measure a differential for preload
shimming (e.g., an automotive feeler gauge).

A 11.2mm [7/16”] drill and ¼”NPT tap for bulkhead fitting
installation.

An automotive bearing puller (e.g., ARB Bearing Puller #0770001)
or a differential carrier bearing puller.

A bearing press or arbor press.

Automotive feeler gauges.
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.

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.

A selection of differential bearing shims to set-up preload and
backlash.

2 Removing the Existing Differential
5
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, chock the wheels (if necessary) and
leave the vehicle in neutral.
2.2 Differential Fluid Drain

Position a fluid drain reservoir under the differential.

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.

Once drained, reinstall the drain plug.
2.3 Removing the Differential Assembly

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.

Disconnect the drive shaft from the drive pinion flange.

Completely remove the entire differential assembly.

2 Removing the Existing Differential
6
2.4 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.
NOTE : As there is no access to the ring gear, ring and pinion
backlash must be measured off of the pinion gear.

Screw a bolt into the flange to measure off, and set a dial indicator
in place as shown. (Refer to Figure 1.)
Figure 1.

2 Removing the Existing Differential
7

Insert a large flat screwdriver or pry-bar through the oil fill hole so
that you can stop the differential from rotating (Figure 2.)
Figure 2.

Gently rotate the pinion gear in both directions and observe 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.

2 Removing the Existing Differential
8
2.5 Removing the Differential Center

Remove all bolts from around the outside of the clamshell.

Gently pry the clamshell apart and remove the differential center.

Remove the floating shaft (or ADD unit if present) from the side of
the differential housing.

Using an arbor press, remove the axle oil seal, both bearing cups
and preload shims by pressing on the face of the shims through the
housing from the outside.
NOTE : Be careful not to damage the axle oil seal when
removing it. If it is damaged, a new one will need to be
ordered from Ford or Mazda before reassembly.
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.

3 Installing the Air Locker
9
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.

Secure the differential to a work bench.

Remove the bolts that hold the ring gear in place.

Using a plastic or copper hammer, gently tap in a circle around the
outside of the ring gear to separate it from the differential carrier.

Remove the original bearings from the differential center using a
bearing puller.
NOTE : The OE differential has a different sized bearing on
each end. The Air Locker has been designed to use
both of these bearing sizes as well.

Examine the bearing cups and cones for damage or wear and, if
necessary, discard them and replace with the same size and type
of bearings.
Figure 3.
FACTORY DIFFERENTIAL

3 Installing the Air Locker
10

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’.

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’.
Figure 4.

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’.
RING GEAR
FLANGE
AIR LOCKER DIFFERENTIAL

3 Installing the Air Locker
11
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

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.

3 Installing the Air Locker
12
3.3 Mounting the Ring Gear

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.

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 Installing the Air Locker
13
3.4 Installing the Carrier Bearings

Apply a thin film of high pressure grease to both bearing journals of
the Air Locker.

Using a bearing press or arbor press, press the smaller 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.

Invert the Air Locker and press the larger bearing cone 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.

3 Installing the Air Locker
14
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.

Assemble the shim pack determined earlier as ‘D’ (Fig.4.) into the
bearing bore of the deep half of the clamshell.

Using a bearing press or arbor press, press the appropriate bearing
cup into the bottom of the same bearing bore (i.e., until it stops
against the shim pack).
HINT : You should not be able to rotate the shim pack
underneath the bearing cup if it has been pressed in
far enough.

With the deep half of the clamshell sitting firmly on a horizontal
surface, set the Air Locker into the bearing cup inside the clamshell.

Bend the seal housing tube so that it points straight away from the
seal housing flange.

Assemble any remaining shims from the Air Locker shim kit
(supplied) together into one shim pack and measure the total
thickness.
AIR LOCKER DIFFERENTIAL

3 Installing the Air Locker
15

Assemble the shim pack onto the seal housing flange on the same
side as the seal housing tube’s solder joint.

Assemble the seal housing into the bearing bore in the shallow half
of the clamshell (shims against the clamshell).

Using a bearing press or arbor press, press the remaining bearing
cup into the bottom of the same bearing bore (until it stops against
the seal housing).

Carefully assemble the shallow half of the clamshell over the top of
the Air Locker.

Measure the preload gap that exists between the two halves of the
clamshell housing with a feeler gauge. (Refer to Fig.7.)
Figure 7.
NOTE : The preload gap should be the same when measured
all the way around the housing. If this is not true, then
reposition the shallow clamshell half and re-measure.
HINT : Sit the assembly in an arbor press and lightly push
down on it. This will help to ensure that the clamshells
halves are sitting evenly.

Subtract the amount measured at the preload gap from the
thickness of the shim pack placed onto the seal housing flange.

Record the result as this is your true ‘end float’ amount.
TOTAL SHIMS – PRELOAD GAP = END FLOAT

3 Installing the Air Locker
16
3.6 Calculation & Selection of Preload Shims

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.

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

Create a shim pack ‘E’ to closely match the measured amount.
NOTE : Shim pack ‘E’ will be at least 1.5mm thick. Use one of
the supplied 1.5mm shims as a part of this shim pack.
NOTE : Do not add shims between the bearing cone and the
bearing seat and NEVER machine the Air Locker.
3.7 Drilling & Tapping the Bulkhead Port
A port must be drilled and tapped through the shallow half of the
clamshell to allow the seal housing tube through the housing to
connect with the air line from the air compressor.

Remove the Air Locker from the housing.

Press the shims, seal housing and bearing cup out of the bearing
bore of the shallow half of the clamshell.

Mark a spot on the shallow half of the clamshell in the same
position shown in the photographs in Figures 8. & 9.

3 Installing the Air Locker
17
Figure 8.
Figure 9.
NOTE : To best determine the correct vertical position of the
drilled hole, measure down from the machined face
(shown at the top of the picture in Figure 9.) a
distance of 18mm [23/32”] and mark the horizontal line
which the hole is centered on. Then refer to Figure 10.
for the correct position on that line to start drilling.
NOTE : Ensure that the bulkhead fitting hole will not interfere
with the existing bolt hole.

3 Installing the Air Locker
18
Figure 10.

Cover the bearing seat area with a rag to protect the inside of the
clamshell from metal filings.

Drill through the housing square to the outside surface using an
11.2mm [7/16”] drill.

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.
Carefully remove the rag and inspect with a service light inside the
clamshell to insure no metal filings are left behind.
3.8 Installing the Seal Housing

Sit the seal housing on top of the shallow clamshell half.

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 lines up with the bulk head fitting hole as shown in
Figure 11.

Mark the tube approximately 8mm [5/16”] out from the end of the
hole (Fig 11. ), and cut with an automotive brake line tubing cutter.
Figure 11.