INSTALLATION GUIDE RD117 DANA 44, 30 SPLINE, 3.73 & DN Part No.
No liability is assumed for damages resulting in the use of the information contained herein. ARB Air Locker Air Operated 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.
Table of Contents: 1 Introduction 3 1.1 Pre-Installation Preparation 1.2 Tool-Kit Recommendations 3 4 2 Removing the Existing Differential 2.1 2.2 2.3 2.4 2.5 2.6 Vehicle Support Differential Fluid Drain Disconnecting the Axles Marking the Bearing Caps Checking the Current Backlash Amount Removing the Differential Center 3 Installing the Air Locker 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.
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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.
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 Standard automotive sizes (metric and/or imperial) of sockets, wrenches, Alan keys, and drills. A dial indicator or other suitable measuring tool for checking ring & pinion backlash. A standard automotive feeler gauge.
2 Removing the Existing Differential 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 Removing the Existing Differential 2.3 Disconnecting the Axles 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.
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.
2 Removing the Existing Differential 2.6 Removing the Differential Center IMPORTANT: YOU MUST SPREAD THE HOUSING ON CAST IRON MODELS Spreading the differential housing with a differential case spreader is a step which is critical to set up bearing pre-load on cast iron differential housings (See Figure 3.). 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. Remove both bearing caps.
2 Removing the Existing Differential NOTE : The differential center is heavy and quite difficult to handle when covered in oil. Take care not to drop it. Relieve any tension on the spreader immediately after the differential has been removed. NOTE : Some Dana 44 type differentials now come from the factory equipped with an OE master shim on the outside of each bearing cup to setup bearing preload. This system is used instead of using a shim pack underneath each bearing cone.
3 Installing the Air Locker 3.1 Insuring Adequate Oil Drainage IMPORTANT: Some Salisbury axles were manufactured with poor oil drainage between the axle tubes and the differential housing. This can often result in one of the axle tubes filling up with differential oil while running.
3 Installing the Air Locker NOTE : Make sure any grinding dust, filings or drill chips left behind by cutting the drainage slots is completely cleaned out of the housing. Check that the axle air vents are clear and working correctly. 3.2 Installing the Carrier Bearings Apply a thin film of high pressure grease to both bearing journals of the Air Locker to prevent seizing.
3 Installing the Air Locker 3.3 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 original 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. Figure 6.
3 Installing the Air Locker Assemble the new bearing cup and ARB master shim (supplied with your Air Locker kit) onto the right-hand side of the Air Locker (as shown in Fig. 7.) and measure the total distance ‘C’. NOTE : The shim pack ‘B’ should not be installed at this time. NOTE : The OE master shim (if present) should not be included in measurement ‘C’. Figure 7. Record this measurement as ‘C’.
3 Installing the Air Locker The thickness of the shim pack ‘B’ should make the distance ‘C’ on the Air Locker closely match the distance ‘A’ on the existing differential (within 0.1mm [0.004”] ). Use the following calculation to find the desired thickness of ‘B’: A – C = B (Replacement Shim Pack) HINT : If your calculations are correct then the following equation will also be true: A – B – C = ZERO Select shims from the shim kit supplied with your Air Locker to make the thickness ‘B’ as determined above.
3 Installing the Air Locker 3.4 Mounting the Ring Gear IMPORTANT: Dana 44 ring gears may use either 3/8”, 7/16”, or 1/2” bolts. For 7/16” bolts re-drill Air Locker flange to 11.5mm [29/64”]. For 1/2” bolts re-drill Air Locker flange to 13.0mm [33/64”]. Apply a thin film of high pressure grease to the ring gear shoulder of the Air Locker to prevent seizing.
3 Installing the Air Locker 3.5 Drilling and Tapping the Bulkhead Port An airline port must be drilled and tapped through the differential housing to mount the bulkhead fitting into. NOTE : Higher ratio gearing uses deeper (thicker) ring gears with teeth that extend much further. Make sure the intended hole location is far enough away from the ring gear teeth that the air line will not be at risk of contact with the current or future ring gears.
3 Installing the Air Locker 3.6 Assembling the Seal Housing Figure 9. 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.
3 Installing the Air Locker Carefully install the seal housing (ARB master shim towards the center) 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. 3.7 Pre-Load Shimming 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 ‘D’ in Figure 9.
3 Installing the Air Locker Figure 11. 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 ‘D’ in Figure 9. PRE-LOAD + END FLOAT = SHIM PACK Create a shim pack ‘D’ from the shims supplied with your Air Locker. NOTE : Do not add shims between the bearing cone and the bearing seat and NEVER machine the Air Locker.
3 Installing the Air Locker Figure 12. Release all spreader tension. Check that some backlash can be felt between the ring and pinion gears. No backlash would be an early indication of incorrect shim thickness.
3 Installing the Air Locker 3.8 Reinstalling the Bearing Caps IMPORTANT: The ARB master shim must be assembled between the stepped side of the seal housing and the bearing cup. NOT HAVING THE ARB MASTER SHIM IN PLACE HERE WILL CAUSE BEARING FAILURE. Using a soft instrument such as a wooden drift, bend the seal housing tube outward and away from the position of the bearing cap. (Fig.13.) Figure 13. NOTE : The seal housing tube should lay as low in the seal housing groove as possible.
3 Installing the Air Locker 3.9 Checking the Backlash Set a depth indicator on one of the ring gear teeth as in Figure 14. 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. Rotate the differential center 90° and measure again for accuracy. Figure 14.
3 Installing the Air Locker 3.9.1 Re-Shimming the Backlash NOTE : This step is only necessary when adjusting for incorrect backlash. Remove the bearing caps. Remove the differential as before. NOTE : Never spread the housing on the aluminum models. To decrease the amount of backlash, reduce the shim thickness ‘B’ (Fig.7.) and increase the shim thickness ‘D’ (Fig.9.) by the same amount. Reverse this step to increase the backlash. Remount the differential as before.
3 Installing the Air Locker Figure 15. NOTE : Excessive tightening of the center compression nut is not necessary to form a good seal around the tube and may damage the O-ring, the seal housing tube, or the threads of the compression nut. NOTE : Make sure the seal housing tube is all of the way into the center compression nut while you are tightening it.
3 Installing the Air Locker 3.11 Profiling the Seal Housing Tube Completely remove the differential spreader. 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 runs along the inside of the differential housing as shown in Figure 16. Figure 16.
4 Installing the Air System 4.1 Mounting the Solenoid 4.1.1 Connection to an ARB Air Compressor (Fig.17.) Remove one of the 1/8” BSP plugs from its port in the compressor tank. Apply Teflon paste to the nipple (1/8” X 1/8” BSP) and insert it into the port and tighten. Apply Teflon paste to the free end of the nipple. Assemble the inlet port side of the solenoid (stamped with a ‘1’) onto the nipple and tighten.
4 Installing the Air System 4.1.2 Connection to an Alternate Air Source For ease of installation, quality of air supply, and a high level of dependability from your Air Locker(s), ARB strongly recommends use of a genuine ARB Air Compressor, however, the Air Locker air system can be operated on any alternate air source that meets each of the following guidelines: Must supply a minimum of 85PSI [586kPa]. The supply must never exceed 105PSI [724kPa].
4 Installing the Air System 4.2 Running and Securing the Air Line The path taken by the air line from your air source (i.e., compressor) to your Air Locker is unique to your vehicle and the position of your air source. Plan ahead carefully when running the air line and always follow these guidelines: Account for axle travel when running the line from the axle to a fixed point on the vehicle. Leave enough slack in the air line to allow for maximum suspension travel in both directions.
4 Installing the Air System To attach the air line to the push-in fitting of the solenoid; insert the line firmly into the fitting, pull outward on the flange of the fitting while holding the line as far into the fitting as possible, and then gently pull outward on the air line to clamp the line in place. 4.
4 Installing the Air System HINT : If the support tube is too difficult to insert, place the end of the air line into a cup of boiled water to soften the tubing. Insert the tube end all the way into the center compression nut. Screw on the outer compression nut and tighten. The ferrule and support tube are now permanently attached. Assemble the support spring over the outside of the outer compression nut. Secure any loose sections of tube with a cable tie.
5 Mounting & Connecting the Electrical System 5.1 Mounting the Actuator Switch(es) Air Locker actuator switch(es) can be easily panel mounted inside the vehicle in a 21mm x 36.5mm [0.83” x 1.44”] rectangular cutout. NOTE : Only attach the cover plate to the face of the switch once the switch has been mounted and wired correctly as the cover plates are designed to be difficult to remove.
5 Mounting & Connecting the Electrical System Figure 19. 5.2 5.2.1 Wiring the Actuator System Connection to an ARB Air Compressor When wiring the Air Locker actuator switch(es) and solenoid(s) to an ARB Air Compressor, all connections can easily be set up directly from the supplied wiring loom. (Fig. 20.) NOTE : Refer to your ARB Air Compressor Installation Guide for details on configuring your installation.
5 Mounting & Connecting the Electrical System ARB AIR COMPRESSOR WIRING LOOM Figure 20. SWITCH TERMINAL IDENTIFICATION UP Figure 21.
5 Mounting & Connecting the Electrical System 5.2.2 Connection to an Alternate Air Source When connecting the actuation switch to an alternate air source, the switch(es) should be wired according to figures 22. and 23., depending on whether one or two Air Lockers will be installed in the vehicle. 5.2.2.1 Single Air Locker System If only one Air Locker is to be installed in the system, the switch and solenoid should be wired according to figure 22.
5 Mounting & Connecting the Electrical System 5.2.2.2 Dual Air Locker System If two Air Lockers are to be installed in the system, ARB recommends that the switches and solenoids be wired according to figure 23. For safety reasons, this configuration allows SOLENOID 2 to be actuated only if SOLENOID 1 is already on. Attach the “REAR AIR LOCKER” switch cover to SWITCH 1, and the “FRONT AIR LOCKER” switch cover to SWITCH 2. NOTE : Refer to Figure 21.
6 Testing & Final Assembly 6.1 Leak Testing With the vehicle parked and the engine off, turn the compressor on and wait until the air system is fully charged. NOTE : With the Air Locker(s) disengaged, the air source (i.e., compressor) should not have to recharge over time. Intermittent recharging without Air Locker use usually indicates a leak at the solenoid fittings or at the compressor tank O-ring seal. Actuate the Air Locker(s).
6 Testing & Final Assembly 6.2.1 Ford IFS (independent front suspension) NOTE : This section applies to the front differentials of Ford IFS equipped vehicles only. The Dana 44 differential supplied on Ford independent front suspension vehicles manufactured since 1983 utilizes a C-clip to retain one front axle. When an Air Locker is installed, this C-clip cannot be reused.
6 Testing & Final Assembly 6.3 Testing the Air Locker Actuation To test that your air system, electrical system, and your Air Locker differential is functioning correctly: Support the vehicle such that the wheels are free to rotate (e.g., on axle stands, a chassis hoist, etc.) Leave the parking brake off, the transmission in neutral, and the Air Locker switch ‘OFF’. Turn the ignition to the ‘ON’ position (leaving the motor off).
6 Testing & Final Assembly 6.5 Post-Installation Check List Now that the Air Locker installation has been completed, ARB recommends that you take the time to complete the following check list just to insure that you haven’t missed any of the vital steps. The air system has been leak tested. Thread locking compound was used on the ring gear bolts. All torque settings comply with the vehicle manufacturer’s specs and were set with an accurate torque wrench.
6 Parts List 40
7 Parts List 7.1 Exploded Assembly Diagram (See itemized parts list overleaf) Figure 25.
7 Parts List 7.2 Itemized Parts List (See exploded diagram figure 25.) AIR LOCKER MODEL No.
