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RD217 LR DISCOVERY 3 & 4, FRONT, 29 SPL AIR OPERATED LOCKING DIFFERENTIAL INSTALLATION GUIDE...
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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...
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. Pre-Installation Preparation This booklet is to be used in conjunction with your vehicle manufacturer’s service manual.
1 Introduction 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. Tools 1.2.1 Standard automotive sizes (metric and/or imperial) of sockets, wrenches, Allan keys, and drills.
2 Removing the Existing Differential 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.
2 Removing the Existing Differential 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.
2 Removing the Existing Differential Insert a large flat screwdriver or pry-bar through the oil drain hole so that you can stop the differential from rotating. 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).
3 Installing the Air Locker 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. ...
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3 Installing the Air Locker 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 2.) and record this measurement as ‘A’.
3 Installing the Air Locker 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.
3 Installing the Air Locker 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.
3 Installing the Air Locker 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 4.) until the bearing seats firmly against the bearing journal shoulder.
3 Installing the Air Locker 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 5. Figure 5.
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3 Installing the Air Locker 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). ...
3 Installing the Air Locker 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.
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3 Installing the Air Locker Figure 7. Figure 8. 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 8.) a distance of 19mm [3/4”] and mark the horizontal line which the hole is centered on.
3 Installing the Air Locker Figure 9. 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. ...
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3 Installing the Air Locker Make sure the seal housing tube and the grooves 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.
3 Installing the Air Locker Installing the Bulkhead Fitting Apply thread sealant to the outside threads of the bulkhead body. Screw the bulkhead body into the tapped hole, and lightly tighten using a 14mm [9/16”] spanner. Wipe the area clean of any excess thread sealant (inside and outside of the housing).
3 Installing the Air Locker NOTE : Make sure the seal housing tube is all of the way into the center compression nut while you are tightening NOTE : Firmly tighten the center compression nut so that a good seal is formed around the tube. Final Assembly 3.11 ...
3 Installing the Air Locker Checking the Backlash 3.12 Refer to your vehicle manufacturer’s service manual for the specified maximum and minimum amounts of backlash. If the backlash measured here is not within the specifications then the differential will have to be re-shimmed. ...
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3 Installing the Air Locker Re-Shimming the Backlash 3.12.1 NOTE : This step is only necessary when adjusting for incorrect backlash. Remove the bolts from the clamshell housing. With the shallow half of the clamshell sitting firmly on a horizontal surface, lift off the deep half of the clamshell.
3 Installing the Air Locker Bench Testing the Air Locker 3.13 To bench test the Air Locker; when 620kPa [90 PSI] shop air is applied to the seal housing tube, the Air Locker should engage. Check all fittings and the seal housing for air leaks. ...
3 Installing the Air Locker Reinstalling the Differential Assembly 3.14 Ensure that any oil seals you removed from the differential housing have been either re-installed or replaced. Reassemble the differential assembly according to your vehicle manufacturer’s service manual using gasket sealant where necessary.
4 Installing the Air System Mounting the Solenoid Connection to an ARB Air Compressor 4.1.1 (Fig.15.) Remove one of the 1/8” BSP plugs from its port in the compressor tank. Apply Teflon paste to the 1/8” BSP nipple on the solenoid and insert it into the port and tighten.
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4 Installing the Air System Connection to an Alternate Air Source 4.1.2 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: ...
4 Installing the Air System 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: ...
4 Installing the Air System Connection to the Bulkhead Fitting Trim the air line to length using a sharp knife. Assemble an aluminium washer onto the banjo bolt and insert through the banjo fitting. Assemble second aluminium washer and tighten into bulkhead fitting using a 14mm [9/16”] spanner.
5 Mounting & Connecting the Electrical System 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 Wiring the Actuator System Connection to an ARB Air Compressor 5.2.1 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.18.).
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5 Mounting & Connecting the Electrical System SWITCH TERMINAL IDENTIFICATION Figure 19. Connection to an Alternate Air Source 5.2.2 When connecting the actuation switch to an alternate air source, the switch(es) should be wired according to Figures 20. and 21., depending on whether one or two Air Lockers will be installed in the vehicle.
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5 Mounting & Connecting the Electrical System Dual Air Locker System 5.2.2.2 If two Air Lockers are to be installed in the system, ARB recommends that the switches and solenoids be wired according to Figure 21. For safety reasons, this configuration allows SOLENOID 2 to be actuated only if SOLENOID 1 is already on.
6 Testing & Final Assembly 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.
6 Testing & Final Assembly Turn the Air Locker switch to the ‘ON’ position. The illuminated symbol on the switch cover should light up. Rotate the same wheel again. Both wheels should rotate together. Turn the switch off again. ...
6 Testing & Final Assembly 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. ...
7 Parts List RD217 LR Discovery 3 + 4, FR, 29 SPL Exploded Assembly Diagram (see itemized parts list overleaf) Figure 22. Specifications Axle Spline 29 tooth, Ø31.5mm [1.24”] Ratio Supported Ring Gear ID 118.0mm [4.64”] Ring Gear OD 190mm [7.48”] Ring Gear Bolts 10 bolts on Ø145.5mm [5.72”]...
7 Parts List Itemized Parts List (see exploded diagram Fig. 22.) ITEM # DESCRIPTION PART # NOTES BONDED SEAL 160701SP CLUTCH GEAR & WAVESPRING KIT 050902SP PINION THRUST WASHER SEE NOTE PINION GEAR SEE NOTE LONG CROSS SHAFT 061302SP SHORT CROSS SHAFT 061402SP SIDE GEAR SEE NOTE...
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