ARB AIRLOCKER RD231 User manual

RD231
NISSAN R180A, 30 SPLINE,
3.54 & DOWN
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 [email protected]
North & South American enquiries [email protected]
Other international enquiries [email protected]
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 Axles & Differential
5
2.4
Marking the Bearing Caps
6
2.5
Checking the Current Backlash Amount
6
2.6
Removing the Differential Carrier
7
3 Bench Measurement
8
3.1
Approximate Backlash Shimming
8
3.2
Calculation & Selection of Shims
9
4 Installing the Air Locker
11
4.1
Installing the Carrier Bearings
11
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 Backlash Checking
19
4.8
Profiling the Seal Housing Tube
20
4.9
Setting Up the Bulkhead Fitting
22
4.10
Bench Testing the Air Locker
24
4.11
Reinstalling the Differential and Axles
25
5 Installing the Air System
26
5.1
Mounting the Solenoid
26
5.2
Running & Securing the Air Line
28
5.3
Connection to the Bulkhead Fitting
29
6 Mounting & Connecting the Electrical System
30
6.1
Mounting the Actuator Switch(es)
30
6.2
Wiring the Actuator System
31
7 Testing & Final Assembly
35
7.1
Leak Testing
35
7.2
Testing the Air Locker Actuation
35
7.3
Filling the Differential
36
7.4
Post-Installation Check List
37
8 Parts List
39
8.1
Exploded Assembly Diagram
39
8.2
Specifications
39
8.3
Itemized Parts List
40

2

1 Introduction
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!

1 Introduction
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 standard automotive feeler gauge.
 A razor knife to cut the nylon tubing.
 A torque wrench. (See vehicle service manual for required torque
range.).
 A lubricant drain reservoir.
 Suitable measuring tools to measure a differential for pre-load
and/or backlash shimming. (See Section 3 Bench Measurement)
 An 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.
 A soft hammer (e.g. copper/rawhide/nylon etc.)
1.2.2 Supplies
 Thread lubricant/sealant compound for pressure fittings. (e.g.,
LOCTITE #567 Teflon paste)
 Thread locking compound (e.g., LOCTITE #272)
 A gasket sealant or replacement gasket for your third member.
 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.

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 off the ground, release the parking brake and
leave the vehicle in neutral. Chock the wheels if necessary.
2.2 Differential Fluid Drain
 Clean around the differential drain plug to prevent dirt from entering
the differential.
 Position a fluid drain reservoir under the differential.
 Remove fluid drain plug to empty all differential oil.
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 & Differential
 Remove the front wheels from the vehicle.
 Disconnect the drive shaft from the flange of the differential.
 Remove the front axle assembly according to your vehicle
manufacturer service manual.
 Secure the assembly to a work bench, and remove the cover plate.
 Remove the oil seal at the end of the axle housing (long axle tube)
using suitable tool to gain access to the circlip holding the axle
assembly.
 Remove the axle assembly from the differential housing.
 Leave the oil seal on the diff case side in place.
HINT : Rubber oil seals can get damaged easily. The flange
will usually get deformed during the removal process. If
a new seal is needed, contact your local Nissan
distributor and quote part number 40227-EA000 (Front
Final Drive RHS Seal) for a replacement.

2 Removing the Existing Differential
6
2.4 Marking the Bearing Caps
 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.

2 Removing the Existing Differential
7
 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 flange, 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.
2.6 Removing the Differential Carrier
 Unbolt and remove the bearing caps.
 Using a suitable tool, carefully remove the differential by pulling
forward on the differential carrier.
NOTE : NEVER spread an aluminium housing as it may initiate
cracks on excessive spreading force.

3 Bench Measurement
8
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.
 Secure the differential to a work bench.
 Remove the bolts that hold the ring gear in
place.
 Using a plastic or copper hammer, tap in a
circle around the ring gear to separate it
from the differential carrier.
 Remove the original bearings from the
differential center using a bearing puller
(Fig. 3.).
NOTE : Keep the bearings and shims
separated so that they can be
identified as to which end of the
differential they came from.
Figure 3.
 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.

3 Bench Measurement
9
 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’.
 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.
 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’.
3.2 Calculation & Selection of 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 on this end,
however, quite often these measurements will vary slightly between
one factory differential and the next.

3 Bench Measurement
10
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 Fig. 5.
Use the following calculation:
A + B –C = D (Replacement Shim Pack)
HINT : If your calculations are correct then the following
equation will also be true:
A + B –C –D = ZERO
 Create a shim pack to match the thickness calculated as ‘D’ and
add it between the factory shim and the bearing cup.
To achieve the desired shim thickness you can:
• Select shims from the shim kit 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.
NOTE : NEVER machine the Air Locker.

4 Installing the Air Locker
11
4.1 Installing the Carrier Bearings
 With the Air Locker well supported in an arbor press, apply a thin
film of high pressure grease to both bearing journals.
 Identify the bearings according to where each was removed from
the OE diff, and allocate them to the correct sides of the Air Locker
respectively.
 Press one of the tapered roller bearing cones onto one of the
bearing journals of the Air Locker until the bearing seats firmly
against the bearing journal shoulder (Fig. 6.).
NOTE : Never re-use any bearings which are damaged or
worn.
 Invert the Air Locker and press the second bearing cone onto the
opposite bearing journal until the bearing seats firmly against the
bearing journal shoulder.
Figure 6.
NOTE : Do not add any shims between the seal housing
bearing and the bearing seat.

4 Installing the Air Locker
12
4.2 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 of the ring gear and the Air Locker
flange.
NOTE : Rubbing the ring gear mounting face with a flat oil
stone before installation will remove any high spots
around the threads.
 Heat the ring gear to between 80 and 100C (175 - 212F) in an
oven or in hot water 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 ring gear with compressed air (if wet), paying particular
attention to the threaded holes.
 Install the ring gear onto the Air Locker by aligning the holes in the
flange with the tapped holes in the ring gear, then gently tapping it
around in a circle with a plastic or copper hammer.
NOTE : 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.
NOTE : 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.

4 Installing the Air Locker
13
4.3 Assembling the Seal Housing
Figure 7.
 Make sure the grooves and airway of the seal housing are clean
and free from any contaminants (e.g. water, dirt, metal filings, etc.).
 Inspect the seal housing O-rings (supplied) for dirt, damage or
other conditions which might cause leaks.
 Generously lubricate the O-rings with oil prior to assembly, then
insert them into the grooves of the seal housing.
NOTE : When assembling the O-rings, be careful not to leave
them twisted when seated in the grooves as this could
cause excessive wear and leakage.
 Lubricate the seal housing running surface on the Air Locker carrier
with oil. Assemble the bearing cup onto the ring gear side.
NOTE : No shims should be assembled onto the seal housing
at this time. The bearing cup should sit directly
against the seal housing.
 Carefully install the seal housing by sliding it all of the way onto the
bearing journal with a gentle twisting motion. This will allow the O-
rings to engage gently.

4 Installing the Air Locker
14
4.4 Calculation & Selection of Pre-Load Shims
In order to pre-load the tapered roller bearings in your Air Locker,
measurements need to be taken so that a value can be calculated for
the shim thickness ‘E’ in Figure 7.
 Hold the bearing cup and shim pack ‘D’ (Fig. 5.) in place, and insert
the Air Locker into the housing.
 Install one bearing cap on the case side. The bearing cap on the
seal housing side will need to be drilled as clearance for the seal
housing tube.
 Install the bearing cap bolts on the case side finger tight.
 Push the Air Locker hard across against the bearing and shim pack
‘D’, and measure the gap between the seal housing and the OE
master shim with a feeler gauge.
NOTE : This ‘end float’ measurement determines the shim
thickness necessary to achieve ‘neutral pre-load’.
Adding more shim than this measurement becomes
the actual ‘pre-load’.
 Consult your vehicle manufacturer’s service manual to determine
the carrier bearing pre-load amount specified for your vehicle.
 Add the specified pre-load amount to the measurement taken with
the feeler gauge to determine a shim amount for ‘E’ in Figure 7.
PRE-LOAD + END FLOAT = SHIM PACK
 Select suitable shims from the shim kit supplied with your Air
Locker to make up a shim pack of this thickness. (Refer to section
3.2 for methods of shim adjustment).
 The seal housing will have to be removed in order to add shim pack
‘E’. Ensure that the seal housing is re-installed correctly.

4 Installing the Air Locker
15
4.5 Drilling and Tapping the Bulkhead Port
An air line port must be drilled and tapped through the differential
housing to mount the bulkhead fitting into.
 Mark a spot on the exterior of the differential cover plate in the
position shown in Figure 8. (i.e., toward the 10 o’clock hole, in the
flat area that will be accessible from the outside and clear of all
moving components inside).
Figure 8.
 Secure the differential cover plate to a work bench.
 Drill an 11.2mm [7/16”] diameter hole through the cover plate
square to the outside surface.
 Tap the hole from the outside using ¼”NPT thread tap.
 Remove any sharp edges that may chip off from around the hole
and fall into the housing.
 Thoroughly clean the cover plate to remove any filings from drilling.

4 Installing the Air Locker
16
4.6 Modifying the Bearing Cap
Clearance for the seal housing tube must be made in the bearing cap.
4.6.1 Marking the Tube Position
 Without using a spreader, fill the gap (end float) between the
master shim and the housing with a required thickness of shims.
 Ensure the Air Locker is securely fitted in place and there is no
significant movement when you push it left and right.
 An accurate measurement for the seal housing tube clearance can
now be made.
NOTE : Take time and double check when taking your
measurements, as bearing caps are custom fitted to
the axle housing and cannot be replaced.
 With the seal housing tube pointing straight out, measure the
distance from a fixed position inside the differential housing to the
center of the seal housing tube. (Fig. 9.)
Figure 9.
 Record your findings and recheck for accuracy.
 Remove the bearing cap from the case side of the differential.
 Remove the Air Locker from the differential housing.
 Install the seal housing side bearing cap and hand-tighten the
bearing cap bolts.

4 Installing the Air Locker
17
 Measure to the bearing cap from exactly the same position on the
differential housing that you took the previous measurements from.
(Fig. 10.)
 Mark the tube position where the clearance is to be made for the
seal housing tube with a center punch.
Figure 10.
 Remove the bearing cap from the differential housing.
 Measure the distance from the center punch mark made on the
bearing cap to the closest edge of the bearing cap.
 The center punch mark should be greater than 5mm [3/16”] from
the closest edge of the bearing cap.
NOTE : Do not file a notch or have the hole less than 5mm
from the edge as this will weaken the aluminium
bearing cap.

4 Installing the Air Locker
18
4.6.2 Drilling the Bearing Cap
 Hold the bearing cap steady for drilling in a soft jawed vise clamp.
NOTE : Do not apply too much clamping pressure with the
vise. The bearing cap may be damaged.
 Using a pedestal drill, drill a 6.35 [1/4’’] hole through the bearing
cap where the seal housing tube hole has been marked.
(Fig. 11.)
Figure 11.
 The drilled hole must be chamfered remove any sharp edges that
may chip-off and fall into the housing. (Fig. 12.)
Figure 12.