Amboid Rear Differential Carrier

Maintenance Manual MM-0990 Amboid Rear Differential Carrier Rear/Rear Carrier on MT-40-14X Series Tandem Drive Axles Revised 09-15

Service Notes About This Manual This manual provides instructions for the amboid rear/rear carrier on Meritor MT-40-14X Series tandem axles. Before You Begin 1. Read and understand all instructions and procedures before you begin to service components. 2. Read and observe all Warning and Caution hazard alert messages in this publication. They provide information that can help prevent serious personal injury, damage to components, or both. 3. Follow your company s maintenance and service, installation, and diagnostics guidelines. 4. Use special tools when required to help avoid serious personal injury and damage to components. If Tools and Supplies Specified in This Manual Contact Meritor s Commercial Vehicle Aftermarket at 888-725-9355. Hazard Alert Messages and Torque Symbols WARNING A Warning alerts you to an instruction or procedure that you must follow exactly to avoid serious personal injury and damage to components. CAUTION A Caution alerts you to an instruction or procedure that you must follow exactly to avoid damage to components. @ This symbol alerts you to tighten fasteners to a specified torque value. How to Obtain Additional Maintenance, Service and Product Information Visit Literature on Demand at meritor.com to access and order additional information. Contact the Meritor OnTrac Customer Call Center at 866-668-7221 (United States and Canada); 001-800-889-1834 (Mexico); or email OnTrac@meritor.com Information contained in this publication was in effect at the time the publication was approved for printing and is subject to change without notice or liability. Meritor Heavy Vehicle Systems, LLC, reserves the right to revise the information presented or to discontinue the production of parts described at any time. Meritor Maintenance Manual MM-0990 (Revised 09-15)

Contents pg. 1 Section 1: Exploded View 3 Section 2: Introduction Description Amboid Rear Differential Carrier 4 Stall-Testing Can Damage a Drive Axle Use of Traction Chains Identification Model Number 6 Section 3: Removal and Disassembly Removal Fasteners Secured with Adhesive Axle Shafts 8 Differential Carrier from the Axle Housing 9 Differential and Ring Gear from the Carrier 12 Drive Pinion from the Carrier 14 Section 4: Prepare Parts for Assembly Clean, Dry and Inspect Parts Clean Ground and Polished Parts Clean Rough Parts Clean Axle Assemblies Dry Parts Immediately After Cleaning 15 Corrosion Protection Prevent Corrosion on Cleaned Parts Inspection Inspect Parts 16 Repair Repair or Replace the Parts 17 Repair Welding on Axle Housings Removal Fasteners Secured with Adhesive Prepare the Differential for Reassembly Carrier-to-Housing Joint Sealing Procedure 18 Installation Fasteners 19 Applying Adhesive and Silicone Gasket Material 20 Identification Gear Sets 21 Check for Mismatched Ratios on Tandem Axles Gear Set Ratios Listed on the Identification Tags Rotate the Forward Drive Shaft to Check the Gear Set Ratio 22 Gear Set Teeth Numbers Stamped on the Forward and Rear Axle Drive Pinions 23 Verify the Actual Gear Set Ratios Inspection Yoke 24 Tire Matching for Tandem Axles pg. 25 Section 5: Assembly and Installation Installation Dry Fit and Final Assembly and Installation Procedures Installing the Drive Pinion, Adjusting Pinion Depth and Contact Pattern Drive Pinion Shim Pack Thickness 26 Assembly Dry Fit Assembly of the Drive Pinion to Verify Shim Pack 28 Installation Drive Pinion 29 Assembly Main Differential and Ring Gear 31 Check the Rotating Resistance of the Differential Assembly 32 Installation Dry Fit Installation of the Main Differential Case and Ring Gear Assembly Into the Carrier 34 Adjustment of Pinion Shim Pack and Backlash for Contact Pattern Ring Gear Backlash Gear Set Tooth Contact Patterns 38 Installation Final Installation of the Drive Pinion and Bearing Preload Adjustment 40 Final Installation of the Main Differential Case and Ring Gear Assembly Into the Carrier 42 Adjustment Differential Bearings Preload 44 Ring Gear Runout 45 Installation Unitized Pinion Seal and Yoke 47 Install the Differential Carrier into the Axle Housing 48 Install the Axle Shafts 50 Section 6: Lubrication Lubrication 52 Section 7: Specifications Fasteners 56 Section 8: Vehicle Towing Instructions Before Towing or Drive-Away 57 After Towing or Drive-Away 58 Section 9: Special Tools Special Tools How to Make a Yoke Bar 59 Carrier Repair Stand Specifications 60 Multiple Lip Seals (MLS) and Seal Drivers

1 Exploded View 1 Exploded View Figure 1.1 28 29 30 31 32 45 34 46 44 47 48 49 50 51 52 33 35 36 37 43 39 38 42 30 29 28 34 33 14 15 16 27 40 41 13 9 8 17 10 11 23 22 25 24 21 26 16 1 2 3 4 5 6 7 12 9 18 20 19 17 15 14 13 4007420a Item Description 1 Yoke Locknut 2 Flat Washer 3 Yoke 4 Deflector 5 Oil Seal Assembly 6 Bearing Cone 7 Bearing Cup 8 2.25-inch Capscrew 9 Hardened Washer 10 Tapered Dowel 11 Carrier Housing Item Description 12 1.75-inch Capscrew 13 Lock Plate 14 Capscrew 15 Washer 16 Bearing Cap Capscrew 17 Bearing Cap 18 Name Plate 19 Locknut 20 Thrust Screw 21 Drive Gear Thrust Block 22 Spacer Meritor Maintenance Manual MM-0990 (Revised 09-15) 1

1 Exploded View Item Description 23 Large Spacer 24 Drive Pinion Shims 25 Bearing Cup 26 Bearing Cone 27 Drive Pinion 28 Adjusting Ring 29 Bearing Cup 30 Bearing Cone 31 Case Half Capscrew 32 Differential Case Half 33 Ring Gear-to-Flange Half Capscrew 34 Ring Gear 35 Differential Washer 36 Side Gear 37 Thrust Washer 38 Pinion Gear 39 Differential Spider 40 Washer (If Equipped) 41 Nut (If Equipped) 42 Magnetic Plug 43 Magnets 44 Name Plate 45 Short Axle Shaft 46 Breather 47 Beather Hose 48 Magnetic Plug 49 Heat Indicator Plug 50 Fill Plug 51 Axle Housing 52 Long Axle Shaft 2 Meritor Maintenance Manual MM-0990 (Revised 09-15)

2 Introduction 2 Introduction Description Amboid Rear Differential Carrier The Meritor single-reduction amboid rear differential carrier is used on MT-40-14X tandem drive axles. Figure 2.1. The amboid design minimizes driveline angle configuration and places the drive pinion above the centerline, which helps to reduce vibration during operation. The carrier is front-mounted into the axle housing and has an amboid drive pinion and ring gear set. All bearings in the carrier are tapered roller bearings. When the carrier operates, there is normal differential action between the wheels at all times. Figure 2.1 AMBOID DRIVE PINION AND RING GEAR TAPERED ROLLER BEARINGS CARRIER TAPERED ROLLER BEARING AXLE HOUSING BEVEL DIFFERENTIAL GEARS TAPERED ROLLER BEARING 4008099a Figure 2.1 Meritor Maintenance Manual MM-0990 (Revised 09-15) 3

SERIAL NO. RATIO 2 Introduction Stall-Testing Can Damage a Drive Axle Stall-testing is a procedure used to troubleshoot transmissions, evaluate vehicle performance, and test the service and park brakes. During stall-testing, or any similar procedure, the drive axle input receives multiplied torque, which can exceed the specified torque rating. Excessive torque can damage a drive axle, which will affect axle performance and component life. A drive axle damaged by stall-testing will void Meritor s warranty. Call the Meritor OnTrac Customer Call Center at 866-OnTrac1 (668-7221) if you have questions regarding stall-testing. Use of Traction Chains Meritor recommends that if you are using traction chains, you should install chains on both tires on each side of all drive axles on the vehicle. Figure 2.3 Figure 2.3 CARRIER PART NO. CUSTOMER NO. SERIAL NO. RATIO CARRIER IDENTIFICATION TAG Refer to Figure 2.4 for an explanation of the model number. CARRIER PART NO. CUSTOMER NO. 4008212a Identification Model Number An identification tag is attached to the axle housing or the differential carrier. Figure 2.2 and Figure 2.3. Use the model number and the ratio number marked on the identification tag and the number on the carrier to obtain replacement parts. Figure 2.2 AXLE IDENTIFICATION TAG INFORMATION Model No.................... Customer No................. Serial No......... Plant........ Ratio............ IDENTIFICATION TAG LOCATION OF THE IDENTIFICATION TAG, OR STAMP NUMBER, FOR THE AXLES. LOCATION IS DETERMINED FROM THE LEFT DRIVER SIDE LOOKING TOWARD THE FRONT OF THE VEHICLE. FRONT ENGINE DRIVE RIGHT REAR, NEXT TO COVER Figure 2.2 4008141a 4 Meritor Maintenance Manual MM-0990 (Revised 09-15)

2 Introduction Figure 2.4 Meritor MS/MT-14X Current Drive Axle Model Nomenclature GAWR xx = GAWR (000) Pounds or Tons (dependent on mfg. location) Axle Model Type* S = Single Rear (Solo) D = Fwd Rear w/iad N = Fwd Rear less IAD P = Fwd Rear w/pump R = Rear Rear T = Tandem Drive Z = Tridem Drive C = Coach H = High Entry V = Fwd Rear w/no thru shaft Carrier Type Carrier size. Larger numbers indicate a higher GCW rated carrier; i.e., larger ring gear etc. Housing Wall 0 = Cast 1=TBD 2 = 0.31 in. (8 mm) 3 = 0.37/0.39 in. (9.5/10.0 mm) 4 = 0.43 in. (11 mm) 5 = 0.50/0.51 in. (12.7/13.0 mm) 6 = 0.56 in. (14.3 mm) 7=TBD 8 = 0.63 in. (16 mm) 9=TBD Carrier Variation A = Aluminum B = Aluminum/Ductile Amboid (Tandem Split) C = Ductile/Ductile Amboid (Tandem Split) D = Ductile Rear, Hyboid E = Aluminum/Ductile (Tandem Split) F = Ductile Amboid/Ductile Hypoid (Tandem Split) H = Ductile Amboid/Spiral Bevel (Tandem Split) M = Ductile Rear, Amboid N = No Carrier R = Ductile Front Drive Axle Carrier, Right Hand M x - xx - x x x x x x x x x - x x x - x x x x M S - 2 1-1 4 X 5 D B R N Q - 1 2 3-3 5 5 M = Meritor Axle Type 0 = No Carrier 1 = Single Speed 2 = Two Speed 3 = Helical Double Reduction 4 = Salisbury 5 = Planetary Double Reduction 6 = Planetary Hub Reduction 7 = Portal 8 = Bevel Hub Reduction 9 = Single Speed with Torque Output Limited Engine Main Differential Nest Type A = DCDL/Standard (Tandem Split) B = Special Differential C = Driver Controlled Differential Lock DCDL D = DCDL/NoSPIN (Tandem Split) E = Standard/DCDL (Tandem Split) F = Standard Differential G = Standard/NoSPIN (Tandem Split) H = High Traction Differential J = NoSPIN /DCDL (Tandem Split) K = NoSPIN /Standard (Tandem Split) L = No Differential N = NoSPIN * For Front Drive Steer Axles, refer to page 6. MFG Location A = Australia/Asia/Africa E = Europe N = North America S = South America T = Telma Retarder (U.S.A.) Wheel End/Brake Attachment A = Conventional Spindle/Conventional Brake E = Unitized Spindle/Conventional Brake J = Conventional Spindle/Integral Brake L = Conventional L Spindle/Conventional Brake N = Unitized Spindle/Integral Brake R = Conventional R Spindle/Conventional Brake S = Bolt on Conventional Spindle/ Conventional Brake NOTE: The term Tandem Split refers to when there is a difference between the Forward axle and Rear axle of the Tandem or Tridem axle set when the Tandem or Tridem axle set part number is used. The value to the left of the / references the Forward axle, and the number to the right of the / references the Rear axle. For information related to the Middle axle of a Tridem axle set part number, refer to the Bills of Material. Ratio 1 Specification Number Includes: TRACK, PARKING BRAKE, OTHER. Brake Type B = B Frame Brake C = Air Disc Brake D = Wedge Brake, Dual Air Chambers E = Wedge Brake, Dual Hydraulic Cylinders F = Wedge Brake, Single Hydraulic Cylinder G = DuraPark Hydraulic Drum H = Quadraulic Disc K = EX+ Air Disc L = Q+ Cam Brake N = None P = P Series Cam Brake Q = Q Series Cam Brake R = Cast+ Brake S = Wedge Brake, Single Air Chamber T = T Series Cam Brake V = Simplex Air Cam Brake W = W Series Cam Brake Z = Non-Meritor Brake 4007403b Figure 2.4 Meritor Maintenance Manual MM-0990 (Revised 09-15) 5

3 Removal and Disassembly 3 Removal and Disassembly Hazard Alert Messages Read and observe all Warning and Caution hazard alert messages in this publication. They provide information that can help prevent serious personal injury, damage to components, or both. 4. Place jackstands under each spring seat of the axle to hold the vehicle in the raised position. Figure 3.1. Figure 3.1 WARNING To prevent serious eye injury, always wear safe eye protection when you perform vehicle maintenance or service. Park the vehicle on a level surface. Block the wheels to prevent the vehicle from moving. Support the vehicle with safety stands. Do not work under a vehicle supported only by jacks. Jacks can slip and fall over. Serious personal injury and damage to components can result. Use a brass or synthetic mallet for assembly and disassembly procedures. Do not hit steel parts with a steel hammer. Pieces of a part can break off. Serious personal injury and damage to components can result. Figure 3.1 SAFETY STANDS 1002983a Removal Fasteners Secured with Adhesive If it s difficult to remove fasteners secured with Dri-Loc, Meritor specification 2297-T-4180 or Loctite 277 adhesive, use the following procedure. 5. Remove the plug from the bottom of the axle housing and drain the lubricant from the assembly. 6. Disconnect the driveline universal joint from the pinion input yoke or flange on the carrier. Figure 3.2. CAUTION When you remove fasteners secured with adhesive, slowly heat the fastener to 350 F (177 C). Do not exceed this temperature, or heat fasteners quickly. Damage to components can result. 1. Heat a fastener for three to five seconds only. Try to loosen the fastener with a wrench. Do not use an impact wrench or hit the fastener with a hammer. 2. Repeat Step 1 until you can remove the fastener. Axle Shafts 1. Wear safe eye protection. 2. Park the vehicle on a level surface and block the wheels to prevent the vehicle from moving. 3. Raise the end of the vehicle where the axle is mounted. Use a jack or other lifting tool, and place safety stands under each side of the axle. 6 Meritor Maintenance Manual MM-0990 (Revised 09-15)

3 Removal and Disassembly Figure 3.2 EASY SERVICE TM 9 1 3 2 7. Remove the stud nuts and washers from the flanges of both axle shafts. 8. Loosen the tapered dowels, if equipped, in the axle flanges of both axle shafts using one of the following methods. Brass Drift Method 8 7 5 6 4 WARNING Do not strike the round driving lugs on the flange of an axle shaft. Pieces can break off and cause serious personal injury. WING SERIES PERMALUBE TM 14 10 13 12 11 NOTE: You can use a 1-1/2-inch (38 mm) diameter brass hammer as a drift. 1. Hold a 1-1/2-inch (38 mm) diameter brass drift against the center of the axle shaft, inside the round driving lugs. Figure 3.3. 15 FULL-ROUND Figure 3.3 BRASS HAMMER 16 24 19 25 1 FULL-ROUND BEARING CUPS 2 END YOKE 3 YOKE SADDLE 4 WELD YOKE 5 BEARING STRAP 6 CAPSCREWS 7 EASY-SERVICE BEARING CUPS 8 U-JOINT CROSS 9 SLIP YOKE 10 CAPSCREWS 11 END YOKE 12 WELD YOKE Figure 3.2 20 18 23 17 22 13 SLIP YOKE 14 U-JOINT CROSS 15 CAPSCREWS 16 END YOKE 17 WELD YOKE 18 SLIP YOKE 19 U-JOINT CROSS 20 CAPSCREWS 21 END YOKE 22 SLIP YOKE 23 TUBING 24 U-JOINT CROSS 25 WELD YOKE RPL SERIES, PERMALUBE TM 21 1002984b Figure 3.3 DRIVING LUGS 1003117b 2. Use a 5-6 lb (2-3 kg) hammer to strike the end of the drift to loosen the axle shaft and tapered dowels. 3. Mark each axle shaft to identify it before you remove it from the axle assembly. 4. Remove the tapered dowels. Separate the axle shafts from the main axle hub assembly. Figure 3.4. Meritor Maintenance Manual MM-0990 (Revised 09-15) 7

3 Removal and Disassembly Figure 3.4 STUD NUT WASHER STUD GASKET 3. Mark each axle shaft to identify it before you remove it from the axle assembly. 4. Remove the tapered dowels. Separate the axle shaft from the main axle hub assembly. Figure 3.4. TAPERED DOWEL, IF EQUIPPED 5. Install a cover over the open end of each axle assembly hub where an axle shaft was removed. Differential Carrier from the Axle Housing AXLE SHAFT OR FLANGE SHAFT HUB AXLE 1002581c 1. Place a hydraulic roller jack under the differential carrier to support the assembly. Figure 3.6. Figure 3.4 Figure 3.6 5. Install a cover over the open end of each axle assembly hub where an axle shaft was removed. Air Hammer Vibration Method CAUTION Do not use a chisel or wedge to loosen the axle shaft and tapered dowels, which can damage the axle shaft, gasket and seal, and axle hub. ROLLER JACK WOOD BLOCK 1002709d 1. Use a round hammer bit and an air hammer to loosen the tapered dowels and axle shaft. 2. Place the round hammer bit against the axle shaft between the hub studs. Operate the air hammer at alternate locations between the studs to loosen the tapered dowels and axle shaft from the hub. Figure 3.5. Figure 3.6 2. Remove all but the top two carrier-to-housing capscrews or stud nuts and washers. 3. Loosen the top two carrier-to-housing fasteners, but leave them attached to the assembly. The fasteners will hold the carrier in the housing. Figure 3.5 ROUND HAMMER BIT BETWEEN HUB STUDS WARNING Use a brass or synthetic mallet for assembly and disassembly procedures. Do not hit steel parts with a steel hammer. Pieces of a part can break off. Serious personal injury and damage to components can result. 4. Loosen the differential carrier in the axle housing. Use a leather mallet to hit the mounting flange of the carrier at several points. 5. After the carrier is loosened, remove the top two fasteners. 1002987a Figure 3.5 8 Meritor Maintenance Manual MM-0990 (Revised 09-15)

3 Removal and Disassembly CAUTION When you use a pry bar, be careful not to damage the carrier or housing flange. Damage to these surfaces will cause oil leaks. 6. Carefully remove the carrier from the axle housing using the hydraulic roller jack. Use a pry bar that has a round end to help remove the carrier from the housing. Take care that you don t damage the carrier or housing flange with the pry bar. Figure 3.8 DIAL INDICATOR NOTE: A carrier stand is available from SPX Kent-Moore. To obtain this tool, refer to the Service Notes page on the front inside cover of this manual. Figure 3.8 1002722d 7. Use a lifting tool to lift the differential carrier by the input yoke or flange. Do not lift the carrier by hand. Place the assembly in a carrier stand. Figure 3.7. Refer to Section 9 to build a stand. 3. Loosen the jam nut on the thrust screw. Use a 12 mm allen-head wrench to loosen the thrust screw. Figure 3.9. Figure 3.9 Figure 3.7 DIFFERENTIAL CARRIER REPAIR STAND 1002710f Loosen thrust screw 1/2 turn. 4000166c Figure 3.7 Differential and Ring Gear from the Carrier 1. Before you begin service procedures on the differential carrier, inspect the gear set for damage. If the gear set isn t damaged: You can reuse the gear set. If the gear set is damaged: Replace it with a new gear set. 2. Measure and record gear set backlash. Figure 3.8. Refer to Step 1 through Step 4 under Ring Gear Tooth Contact Pattern, Backlash in Section 5 for instructions. Adjust backlash to the original dimension when you install the gear set into the carrier during assembly procedures. Figure 3.9 4. Rotate the differential carrier in the repair stand until the ring gear is at the TOP of the assembly. 5. Use a center punch and hammer to mark one carrier leg and bearing cap to correctly match the parts during carrier assembly. Figure 3.10. Meritor Maintenance Manual MM-0990 (Revised 09-15) 9

3 Removal and Disassembly Figure 3.10 Figure 3.12 CARRIER LEG BEARING CAP BEARING CAP Figure 3.10 6. Remove the capscrews and lock plates that secure the bearing adjusting rings in position. Figure 3.11. Figure 3.11 MATCH MARKS 1002994b Figure 3.12 8. Remove the bearing caps and bearing adjusting rings from the carrier. Figure 3.13. Figure 3.13 BEARING CAP BEARING ADJUSTING RING 1002996c LOCK PLATE THREADED HOLES IN CAP 1002748e Figure 3.13 Figure 3.11 1003105f 9. Use a lifting strap to lift the main differential and ring gear assembly from the carrier. Place the assembly onto a work bench. Figure 3.14. 7. Remove the two capscrews and washers that secure the two bearing caps onto the carrier. Figure 3.12. Figure 3.14 1002749h Figure 3.14 10 Meritor Maintenance Manual MM-0990 (Revised 09-15)

3 Removal and Disassembly 10. Remove the thrust screw, jam nut and thrust block from the differential carrier. Inspect the thrust block for heavy wear and replace it, if necessary, during reassembly. Figure 3.9 and Figure 3.15. Figure 3.15 THRUST SCREW AND JAM NUT THRUST BLOCK WARNING Use a brass or synthetic mallet for assembly and disassembly procedures. Do not hit steel parts with a steel hammer. Pieces of a part can break off. Serious personal injury and damage to components can result. 3. Separate the case halves. If necessary, use a brass, plastic or leather mallet to loosen the parts. 4. Remove the differential spider, four pinion gears, two side gears and six thrust washers from the inside of the case halves. Figure 3.17. If you need to replace the ring gear: Remove the bolts, and nuts and washers, if equipped, that secure the gear to the flange case half. Figure 3.17 1002993f THRUST WASHER Figure 3.15 Disassemble the Differential and Ring Gear Assembly NOTE: The marks on the plain half and flange half of the differential assembly case will help you to match them correctly when you assemble the carrier. SIDE GEAR SPIDER, PINIONS AND THRUST WASHERS 1. If the match marks on the plain half and flange half of the differential assembly case are not visible, mark each case half with a center punch and hammer. Figure 3.16. Figure 3.17 1002752c Figure 3.16 MARKS ON BOTH HALVES OF THE DIFFERENTIAL ASSEMBLY CASE WARNING Observe all warnings and cautions provided by the press manufacturer to avoid damage to components and serious personal injury. Figure 3.16 2. Remove the capscrews from the case halves. 1002751c 5. Use a press to separate the flange case half and ring gear. Support the assembly under the ring gear with metal or wood blocks. Press the flange case half through the gear. Figure 3.18. If you need to replace the differential bearings: Use a bearing puller or press to remove the bearing cones from the case halves. Figure 3.19. Meritor Maintenance Manual MM-0990 (Revised 09-15) 11

3 Removal and Disassembly Figure 3.18 FLANGE CASE HALF SUPPORTS PRESS PLATE 2. Remove the nut and washer, if equipped, from the drive pinion. Figure 3.20. 3. Remove the yoke or flange bar. CAUTION If the yoke and flange are difficult to remove from the drive pinion during disassembly, use a puller. Do not use a hammer or mallet, which can damage components and affect driveline alignment and end play. Figure 3.18 1003002d 4. Remove the yoke or flange from the drive pinion. If the yoke or flange is tight on the pinion, use a puller. Figure 3.21. Figure 3.21 Figure 3.19 PULLER YOKE PULLER PRESS Figure 3.19 1002750c FLANGE PULLER Drive Pinion from the Carrier 1. Fasten a flange bar to the input yoke or flange. When you remove the nut, the bar will hold the drive pinion in position. Refer to Section 9 for instructions to make a yoke bar. Figure 3.20. Figure 3.20 1003348d Figure 3.21 FLANGE/YOKE BAR NOTE: Always use a new oil seal during reassembly. Don t reuse a seal that s been removed. 5. Use appropriate prying tools to remove the unitized oil seal from the carrier. Place the blades of the prying tools under the flange to remove the oil seal. Figure 3.22. 4000167b Figure 3.20 12 Meritor Maintenance Manual MM-0990 (Revised 09-15)

3 Removal and Disassembly Figure 3.22 9. Remove the shims from the carrier. If the shims are in good condition: Keep the shims together for use when the carrier is assembled. If the shims are to be discarded because of damage: First measure the total thickness of the pack. Make a note of the dimension. You will need the dimension to calculate the depth of the drive pinion in the carrier when the gear set is installed. 10. Remove the bearing spacer and variable spacer from the pinion shaft. Figure 3.24. Figure 3.22 4000168b WARNING Observe all warnings and cautions provided by the press manufacturer to avoid damage to components and serious personal injury. 6. Place the carrier assembly in a press with the threaded end of the pinion shaft pointing UP. Figure 3.23. Figure 3.24 If you need to replace the pinion bearings: Use a press or bearing puller to remove the inner bearing cone from the drive pinion. The puller must fit under the inner race of the cone to remove the cone correctly without damage. Figure 3.25. SPACERS Figure 3.23 4000170a Figure 3.24 Figure 3.25 Figure 3.23 4000169c INNER BEARING CONE PRESS DRIVE PINION BEARING PULLER 7. Press the pinion shaft out of the outer bearing cone. Do not let the pinion shaft drop to the ground after being pressed out. Figure 3.23. 8. Remove the outer bearing cone from the carrier. If you need to replace the pinion bearings: Use a suitable puller to remove the inner and outer bearing cups from the carrier. Figure 3.25 SUPPORTS 1003012d Meritor Maintenance Manual MM-0990 (Revised 09-15) 13

4 Prepare Parts for Assembly 4 Prepare Parts for Assembly Hazard Alert Messages Read and observe all Warning and Caution hazard alert messages in this publication. They provide information that can help prevent serious personal injury, damage to components, or both. WARNING To prevent serious eye injury, always wear safe eye protection when you perform vehicle maintenance or service. Solvent cleaners can be flammable, poisonous and cause burns. Examples of solvent cleaners are carbon tetrachloride, and emulsion-type and petroleum-base cleaners. Read the manufacturer s instructions before using a solvent cleaner, then carefully follow the instructions. Also follow the procedures below. Wear safe eye protection. Wear clothing that protects your skin. Work in a well-ventilated area. Do not use gasoline or solvents that contain gasoline. Gasoline can explode. You must use hot solution tanks or alkaline solutions correctly. Read the manufacturer s instructions before using hot solution tanks and alkaline solutions. Then carefully follow the instructions. Take care when you use Loctite adhesive to avoid serious personal injury. Read the manufacturer s instructions before using this product. Follow the instructions carefully to prevent irritation to the eyes and skin. If Loctite adhesive material gets into your eyes, follow the manufacturer s emergency procedures. Have your eyes checked by a physician as soon as possible. When you apply some silicone gasket materials, a small amount of acid vapor is present. To prevent serious personal injury, ensure that the work area is well-ventilated. Read the manufacturer s instructions before using a silicone gasket material, then carefully follow the instructions. If a silicone gasket material gets into your eyes, follow the manufacturer s emergency procedures. Have your eyes checked by a physician as soon as possible. Clean, Dry and Inspect Parts Clean Ground and Polished Parts 1. Use a cleaning solvent to clean ground or polished parts or surfaces. Kerosene or diesel fuel oil can be used for this purpose. DO NOT USE GASOLINE. 2. Use a tool with a flat blade, if required, to remove sealant material from parts. Be careful not to damage the polished or smooth surfaces. CAUTION Do not use hot solution tanks or water and alkaline solutions to clean ground or polished parts. Damage to parts can result. 3. Do not clean ground or polished parts with water or steam. Do not immerse ground or polished parts in a hot solution tank or use strong alkaline solutions for cleaning, or the smooth sealing surface may be damaged. Clean Rough Parts 1. Clean rough parts with the same method as cleaning ground and polished parts. 2. Rough parts can be cleaned in hot solution tanks with a weak or diluted alkaline solution. 3. Parts must remain in hot solution tanks until heated and completely cleaned. 4. Parts must be washed with water until all traces of the alkaline solution are removed. Clean Axle Assemblies 1. A complete axle assembly can be steam cleaned on the outside to remove dirt. 2. Before the axle is steam cleaned, close or place a cover over all openings in the axle assembly. Examples of openings are breathers or vents in air chambers. Dry Parts Immediately After Cleaning All Parts Except Bearings Use soft, clean paper, cloth rags or compressed air to dry parts immediately after cleaning. 14 Meritor Maintenance Manual MM-0990 (Revised 09-15)

4 Prepare Parts for Assembly Bearings CAUTION Use soft, clean paper or cloth rags to dry bearings immediately after cleaning. Do not use compressed air, which can damage the bearings when they are rotated and dried. Use soft, clean paper or cloth rags to dry bearings immediately after cleaning. Do not use compressed air. Corrosion Protection Figure 4.1 There is damage on the cup and cone inner race surfaces that touch the rollers. Figure 4.5. WORN RADIUS Prevent Corrosion on Cleaned Parts 1. Apply axle lubricant to cleaned and dried parts that are not damaged and are to be assembled. Figure 4.1 WORN SURFACE 1003017b 2. To store parts, apply a special material that prevents corrosion to all surfaces. Wrap cleaned parts in a special paper that will protect the parts from moisture and prevent corrosion. Figure 4.2 Inspection Inspect Parts CRACK WEAR GROOVES It is very important to inspect all parts carefully and completely before the axle or carrier is assembled. Check all parts for wear and replace damaged parts. 1. Inspect the cup, cone, rollers and cage of all tapered roller bearings in the assembly. If any of the following conditions exist, replace the bearing. The center of the large-diameter end of the rollers is worn level with or below the outer surface. Figure 4.1. The radius at the large-diameter end of the rollers is worn to a sharp edge. Figure 4.1. Figure 4.3 Figure 4.2 1003018b There is a visible roller groove in the cup or cone inner race surfaces. The groove can be seen at the small- or large-diameter end of both parts. Figure 4.2. There are deep cracks or breaks in the cup, cone inner race or roller surfaces. Figure 4.2. There are bright wear marks on the outer surface of the roller cage. Figure 4.3. There is damage on the rollers and on the surfaces of the cup and cone inner race that touch the rollers. Figure 4.4. Figure 4.3 WEAR MARKS 1003019a Meritor Maintenance Manual MM-0990 (Revised 09-15) 15

4 Prepare Parts for Assembly Figure 4.4 ETCHING AND PITTING The four trunnion legs of the spider Teeth and splines of both differential side gears Teeth, bore and spherical backface of all differential pinions Figure 4.6 Figure 4.4 1003020a DIFFERENTIAL CASE HALVES Inspect inside surfaces. Figure 4.5 SIDE GEAR AND THRUST WASHER PINION AND THRUST WASHER Inspect. SPALLING AND FLAKING Inspect. 1003021b Inspect. SPIDER OR CROSS DIFFERENTIAL GEAR NEST ASSEMBLY 1003022i Figure 4.5 CAUTION A drive pinion and ring gear is machined as a matched set. When you replace either a drive pinion or a ring gear, you must replace both parts as a matched set. Do not mix old and new parts. Damage to components can result. 2. Inspect pinions and gears for wear or damage. Replace pinions and gears that are worn or damaged. CAUTION When you need to replace either a thrust washer, differential side gear or pinion gear, you must replace all of these parts with a new set. Do not mix old and new parts. Damage to components can result. 3. Inspect the following main differential assembly parts for wear or stress. Replace parts that are damaged. Figure 4.6. Inside surfaces of both case halves Both surfaces of all thrust washers Figure 4.6 4. Inspect the axle shafts for wear and cracks at the flange, shaft and splines. Replace the axle shafts, if required. Repair Repair or Replace the Parts NOTE: Threads must be without damage and clean so that accurate adjustments and correct torque values can be applied to fasteners and parts. 1. Replace any fastener if corners of the head are worn. 2. Replace the washers if damaged. 3. Replace the gaskets, oil seals or grease seals at the time of axle or carrier repair. 4. Clean the parts and apply new silicone gasket material where required when the axle or carrier is assembled. Figure 4.7. 16 Meritor Maintenance Manual MM-0990 (Revised 09-15)

4 Prepare Parts for Assembly Figure 4.7 Figure 4.7 5. Remove nicks, marks and burrs from parts with machined or ground surfaces. Use a fine file, india stone, emery cloth or crocus cloth. 6. Clean and repair threads of fasteners and holes. Use a die, a tap of the correct size, or a fine file. Repair Welding on Axle Housings Remove silicone gasket from parts. 1003023a For Complete Welding Instructions on Meritor Drive Axle Housings Refer to Maintenance Manual 8, Drive Axle Housings. To obtain this publication, refer to the Service Notes page on the front inside cover of this manual. Prepare the Differential for Reassembly 1. Use a wire brush to remove any hardened adhesive material from the fasteners. 2. Clean the oil and dirt from the outer diameters of the bearing cups and bearing bores in the carrier and bearing caps. There is no special cleaning required. 3. Apply axle lubricant to the bearing cones and the inner diameters of the bearing cups of the main differential. Do not get oil on the outer diameter of the bearing cup and do not permit oil to drip on the bearing bores. Carrier-to-Housing Joint Sealing Procedure 1. Remove the carrier from the housing. Refer to Section 3. 2. Remove all debris from inside the housing. 3. Use a rotary tool with a scour pad to clean all silicone residue from the housing and carrier faces. Figure 4.8. Surfaces must be clean, dry and free of foreign matter. The surfaces must not be oily to the touch. Figure 4.8 Cleaning the housing face with a rotary tool and a mild, non-abrasive pad. Removal Fasteners Secured with Adhesive If it s difficult to remove fasteners secured with Dri-Loc, Meritor specification 2297-T-4180 or Loctite 277 adhesive, use the following procedure. CAUTION When you remove fasteners secured with adhesive, slowly heat the fastener to 350 F (177 C). Do not exceed this temperature, or heat fasteners quickly. Damage to components can result. 1. Heat a fastener for three to five seconds only. Try to loosen the fastener with a wrench. Do not use an impact wrench or hit the fastener with a hammer. 2. Repeat Step 1 until you can remove the fastener. Figure 4.8 4. Remove metal filings from the magnets inside the housing. 5. Use solvent to clean the inside of the housing. 6. Use Loctite ODC Free cleaner or brake cleaner to clean the housing and carrier faces. 7. Dry the housing and carrier faces. 4000621a Meritor Maintenance Manual MM-0990 (Revised 09-15) 17

4 Prepare Parts for Assembly CAUTION New capscrew kits have blue Dri-Loc STS threadlocker, an equivalent to Loctite 242 threadlocker, applied to the capscrews. Do not remove the blue Dri-Loc STS threadlocker from the capscrews. Damage to components can result. 8. If you reuse the carrier-to-housing capscrews, use a rotary wire brush to remove any threadlocker material and clean the capscrew threads. Use a clean cloth to wipe the threads. 13. Apply a 0.125-inch (3 mm) bead of Loctite 242 threadlocker around the capscrew threads approximately 0.25-inch (6 mm) from the end. Apply a 0.125-inch (3 mm) bead of Loctite 242 threadlocker across the length of the threads. Figure 4.10. Figure 4.10 LOCTITE 242 THREADLOCKER APPLICATION 360 LOCTITE BEAD 9. Use a tap of the appropriate thread size and class to clean the internal threads in the housing. CAUTION Apply silicone gasket material in a continuous 0.25-inch (6 mm) bead to the housing face. If you use more than this amount, gasket material can break off and plug lubrication passages. Damage to components can result. 10. Apply a 0.25-inch (6 mm) bead of Loctite 5699 silicone gasket material to the housing face. Do not use ThreeBond 1216E silicone products. Figure 4.9. Figure 4.9 Figure 4.10 0.25" (6 MM) 14. Install the capscrews. Use a crossing pattern to tighten the capscrews evenly. The capscrews must be tightened within 10 minutes of initial application of Loctite 242 threadlocker. Tighten the 5/8-inch capscrews to 210-240 lb-ft (285-325 N m). @ 4000623b 15. Wait a minimum of 60 minutes before filling the assembly with lubricant. Refer to Section 6. Installation Fasteners Figure 4.9 0.25" (6 MM) DIAMETER SILICONE GASKET BEAD 4004435a 11. Install two long studs in the housing to guide the carrier into the housing. Tighten the studs until there are no exposed threads. 12. Immediately install the carrier into the housing to enable the silicone gasket material to compress evenly between the faces. If using a new capscrew kit with blue Dri-Loc STS pre-applied threadlocker, skip the next step. New Fasteners with Pre-Applied Adhesive NOTE: No drying time is required for fasteners with pre-applied adhesive. 1. Use a wire brush to clean oil and dirt from threaded holes. 2. Install new fasteners with pre-applied adhesive to assemble parts. Do not apply adhesives or sealants to fasteners with pre-applied adhesive, or to fastener holes. 3. Tighten fasteners to the required torque value for that size fastener. 18 Meritor Maintenance Manual MM-0990 (Revised 09-15)

4 Prepare Parts for Assembly Original or Used Fasteners Using Meritor Liquid Adhesive 2297-M-5213, Loctite 277 or 270 Adhesive, or Equivalent 1. Use a tool with a flat blade, if required, to remove all old gasket material from surfaces. Figure 4.12. WARNING Take care when you use Loctite adhesive to avoid serious personal injury. Read the manufacturer s instructions before using this product. Follow the instructions carefully to prevent irritation to the eyes and skin. 1. Use a wire brush to clean the oil, dirt and old adhesive from all threads and threaded holes. 2. Apply four or five drops of Meritor liquid adhesive, Loctite 277 or 270 adhesive, or equivalent, inside each threaded hole or bore. Do not apply adhesive directly to fastener threads. Figure 4.11. Figure 4.12 Remove old sealant material. HOUSING AND CARRIER SHOWN 1003027e NOTE: There is no drying time required for Meritor specification 2297-K-5523 liquid adhesive, Loctite 680 adhesive, or equivalent. 3. Tighten the fasteners to the required torque value for that size fastener. Figure 4.11 Figure 4.12 2. Use a cleaning solvent to clean the surfaces where you will apply silicone gasket material. Remove all oil, grease, dirt and moisture without damaging the mating surfaces. Figure 4.12. 3. Dry all surfaces. FOUR TO FIVE DROPS ON BORE THREADS Figure 4.11 1003025a CAUTION Apply silicone gasket material in a continuous 0.25-inch (6 mm) bead. If you use more than this amount, the gasket material can break off and plug lubrication passages. Damage to components can result. 4. Apply a 0.25-inch (6 mm) diameter continuous bead of the silicone gasket material around one surface. Also apply the gasket material around the edge of all fastener holes on that surface. Figure 4.13. Applying Adhesive and Silicone Gasket Material NOTE: The following silicone gasket products or equivalent can be used for Meritor components. Loctite Ultra Grey Adhesive/Sealant number 18581 Meritor part number 2297-H-7054 gasket material. To obtain this gasket material, refer to the Service Notes page on the front inside cover of this manual. Meritor Maintenance Manual MM-0990 (Revised 09-15) 19

4 Prepare Parts for Assembly Figure 4.13 0.25" (6 MM) DIAMETER SILICONE GASKET BEAD Figure 4.13 5. Assemble the components immediately to permit the silicone gasket material to compress evenly between the parts. Tighten fasteners to the required torque value for that size fastener. Refer to Table K in Section 7. 6. Wait 20 minutes before filling the assembly with the correct lubricant. Refer to Section 6. Identification Gear Sets 1003028f Refer to the following examples for information on identifying gear sets with matched parts. Always check the match numbers to verify that the gear set you will install has matched parts. Figure 4.14. Examples Gear Set Part Number Location Conventional ring gear Conventional drive pinion Gear Set Tooth Combination Number Gear Set Teeth 5-37 = gear set has a five-tooth drive pinion and a 37-tooth ring gear Gear Set Match Number XXXXX, XXXXXK2, XXXXXK3, XXXXXK4, XXXXXK5 XXXXX, XXXXXK2, XXXXXK3, XXXXXK4, XXXXXK5 Drive Pinion Location At the end at threads On the front face or outer diameter At the end at threads Ring Gear Location On the front face or outer diameter NOTE: Meritor drive pinions and ring gears are only available as matched sets. Each gear in a set has an alphanumeric match number. Figure 4.14 ALTERNATE LOCATIONS Match Number Drive Pinion Location Ring Gear Location M29 At the end of the gear head On the front face or outer diameter Pinion Cone Variation Number 1003031c NOTE: Don t use the pinion cone variation number when you check for a matched gear set. Use this number when you adjust the pinion depth in the carrier. Refer to Section 5. 1 PART NUMBER, TOOTH COMBINATION NUMBER, GEAR SET MATCH NUMBER, PINION CONE VARIATION NUMBER 2 PART NUMBER, TOOTH COMBINATION NUMBER 3 GEAR SET MATCH NUMBER, PINION CONE VARIATION NUMBER 4 PART NUMBER, TOOTH COMBINATION NUMBER, GEAR SET MATCH NUMBER 5 PART NUMBER, TOOTH COMBINATION NUMBER, GEAR SET MATCH NUMBER Figure 4.14 20 Meritor Maintenance Manual MM-0990 (Revised 09-15)

4 Prepare Parts for Assembly Pinion Cone (PC) Variation Number PC+3 +2 +0.01 mm PC 5 1 0.02 mm Check for Mismatched Ratios on Tandem Axles For a tandem axle pair to function correctly, the forward and rear axles must operate with axle ratios within one percent. A mismatched tandem axle pair can cause carrier overheating, gear set wear, metal debris to collect on the magnetic drain plug, carrier lubricant additive depletion, excessive inter-axle differential wear and noise. To determine if the tandem axle ratios operate within allowable limits, refer to one of the following procedures. Perform the procedure that will work best for the vehicle you are servicing. Gear Set Ratios Listed on the Identification Tags 1. Locate the identification tags attached to the forward and rear axle differential carriers. Figure 4.15. Figure 4.15 Drive Pinion Location At the end of the pinion gear head Ring Gear Location On the outer diameter CARRIER PART NO. CUSTOMER NO. SERIAL NO. RATIO 2. Compare the axle ratios shown on the tags. To operate correctly, the axle ratios for both axles must be within one percent of each other. To calculate the percentage difference between the axle ratios, refer to the equation in Table A. Table A: Larger Ratio Smaller Ratio X 100 = Smaller Ratio If the axle ratios shown on the identification tags are not within one percent of each other: Refer to the vehicle manufacturer for further information. Rotate the Forward Drive Shaft to Check the Gear Set Ratio WARNING Park the vehicle on a level surface. Block the wheels to prevent the vehicle from moving. Support the vehicle with safety stands. Do not work under a vehicle supported only by jacks. Jacks can slip and fall over. Serious personal injury and damage to components can result. 1. Park the vehicle on a level surface. Percentage Difference Between Axle Ratios 2. Engage the inter-axle differential and shift the transmission into NEUTRAL. 3. Block the wheels to prevent the vehicle from moving. 4. Use a jack to raise the vehicle until all the tandem drive axle wheels clear the ground. Support the vehicle with safety stands. 5. Mark the forward and rear tires at identical relative positions. Figure 4.16. Figure 4.16 1 CARRIER PART NO. CUSTOMER NO. SERIAL NO. RATIO 2 1003452c 1 FORWARD 2 REAR Figure 4.15 Figure 4.16 MARKS MARKS 1003453a Meritor Maintenance Manual MM-0990 (Revised 09-15) 21

4 Prepare Parts for Assembly 6. Turn the forward drive shaft in one direction by hand until the forward tire completes two rotations. Figure 4.17. The forward tire must rotate two times only. If the forward tire rotates more than or less than two rotations, the angle measurements you make in Step 7 will be inaccurate. Figure 4.17 Figure 4.17 Rotate two full turns of forward tire. 1003454b 7. Note the positions of the tire marks you previously made. On a correctly matched tandem axle gear set, both tire marks will be within ± 3.6 degrees of each other. Figure 4.18. If the positions of the tire marks are more than 3.6 degrees from each other: Refer to the vehicle manufacturer for further information. Gear Set Teeth Numbers Stamped on the Forward and Rear Axle Drive Pinions When the inter-axle driveline or differential carrier is removed for service, you can check the gear set teeth numbers stamped on the forward and rear axle drive pinions. WARNING Park the vehicle on a level surface. Block the wheels to prevent the vehicle from moving. Support the vehicle with safety stands. Do not work under a vehicle supported only by jacks. Jacks can slip and fall over. Serious personal injury and damage to components can result. 1. Park the vehicle on a level surface. 2. Block the wheels to prevent the vehicle from moving. To Identify the Gear Teeth Number on the Rear Axle Drive Pinion 1. Remove the inter-axle drive shaft. Refer to the vehicle manufacturer s procedures. 2. Identify and record the gear set teeth numbers stamped on the end of the rear axle drive pinion. Figure 4.19. Figure 4.19 Figure 4.18 If the mark appears in the shaded area, the tandem gear set is incorrectly matched. 10-47 LARGER NUMBER SMALLER NUMBER = GEAR SET RATIO 1003457c Figure 4.19 Figure 4.18 3.6 3.6 If the mark appears in this area, the tandem axle gear set is correctly matched. 8. Remove the safety stands and lower the vehicle. 1003455a 3. Calculate the gear set ratio by dividing the larger number by the smaller number. Figure 4.19. Compare Both Gear Set Ratios 1. Both ratios must be within one percent of each other. To calculate the percentage difference between the axle ratios, refer to the equation in Table A. 22 Meritor Maintenance Manual MM-0990 (Revised 09-15)

4 Prepare Parts for Assembly If the axle ratios shown on the identification tags are not within one percent of each other: Refer to the vehicle manufacturer for further information. 2. Install the inter-axle drive shaft. Refer to the vehicle manufacturer s procedures. 3. Remove the safety stands and lower the vehicle. Verify the Actual Gear Set Ratios You can check the actual gear set ratios when you remove the differential carriers from the axle housings for service or repair. Refer to the following procedure to calculate the actual gear set ratios. 1. Count the number of ring gear teeth. Figure 4.20. Figure 4.20 Inspection Yoke All current Meritor axles feature helical splines at the yoke interface. This feature provides a tight fit between the yoke and input shaft, output shaft and pinion shaft. For the axle to operate correctly, the input shaft, output shaft and pinion shaft must fit tightly to the corresponding yoke. Check for Yoke Wear WARNING Park the vehicle on a level surface. Block the wheels to prevent the vehicle from moving. Support the vehicle with safety stands. Do not work under a vehicle supported only by jacks. Jacks can slip and fall over. Serious personal injury and damage to components can result. 1. Park the vehicle on a level surface. Block the wheels to prevent the vehicle from moving. RING GEAR TEETH RING GEAR TEETH PINION GEAR TEETH = Figure 4.20 PINION GEAR TEETH ACTUAL GEAR SET RATIO 2. Count the number of pinion gear teeth. Figure 4.20. 4008210a 3. Divide the number of ring gear teeth by the number of pinion gear teeth to determine the actual gear set ratio for each axle. Figure 4.20. 4. Calculate the percentage difference between the gear set ratios using the equation in Table A. All ratios must match within one percent. If the actual gear set ratios are not within one percent of each other: Refer to the vehicle manufacturer for further information. 2. Use a jack to raise the vehicle so that the wheels to be serviced are off the ground. Support the vehicle with safety stands. 3. Remove the driveline. 4. Remove the input, output or pinion shaft nut. 5. Attempt to remove the yoke by hand. If you can remove the yoke by hand: The yoke is worn. Replace the yoke. 6. Use a correct yoke puller tool to remove the yoke. Check for a Tight-Fit Condition NOTE: You can check for a tight-fit condition when you install any serviceable yoke. 1. Attempt to install the yoke by hand. If the yoke bottoms out against the adjacent bearing: Replace the yoke. 2. Use a correct yoke installation tool to install the yoke. 3. As you install the yoke, you should detect resistance between the yoke and shaft. If you do not detect resistance between the yoke and shaft: Replace the yoke. Meritor Maintenance Manual MM-0990 (Revised 09-15) 23

4 Prepare Parts for Assembly 4. Install and tighten the input, output or pinion shaft nut to the correct torque. Refer to Section 7. 5. Install the driveline. 6. Remove the safety stands. 7. Lower the vehicle. 7. Vary tire air pressure within the tire manufacturer s recommended range so the lubricant temperature of both axles is within 30 F or 17 C of each other and not in excess of 250 F (121 C). This will usually result in uniform tire loading and good tire life. Tire Matching for Tandem Axles CAUTION Unmatched tires on tandem drive units will cause tire wear and scuffing and possible damage to the drive units. Meritor recommends that the tires be matched to within 0.125-inch (3.18 mm) of the same rolling radius, 0.75-inch (19.05 mm) of the same rolling circumference. The four largest tires should never be installed onto one driving axle or the four smallest tires onto the other driving axle. Such tire mounting will cause an inter-axle fight, unusually high axle lubricant temperatures that result in premature lubricant breakdown and possible costly axle service. In addition to matching individual tire rolling radii or rolling circumference, Meritor recommends matching, as nearly as possible, the total tire circumference of one driving axle to the total tire circumference of the other driving axle. This will usually result in satisfactory tandem axle lubricant temperatures that lengthen drive unit service with higher tire mileage. Park the vehicle on a level surface. The vehicle must carry a correctly distributed rated capacity load. All the tires must be the same size. Measure new tires to verify that they will be correctly matched. 1. Inflate all tires to the same pressure. 2. Carefully measure the rolling circumference of each tire with a steel tape. 3. Mark the size on each tire with chalk and arrange the tires in order of size, largest to smallest. 4. Mount the two largest tires onto one side of one axle and mount the two smallest onto the opposite side of the same axle. 5. Mount the four other tires onto the other axle in the same manner. 6. Test run the vehicle to gather accurate rear axle lubricant temperature readings on the two axle lubricant temperature gauges. 24 Meritor Maintenance Manual MM-0990 (Revised 09-15)