GM Service Manual Online
For 1990-2009 cars only

REAR AXLE/SPRING MOUNTING (SERVICE PROCEDURE & P/N'S)

EFFECTIVE WITH 1987 START OF PRODUCTION, THE EATON T175 REAR AXLE WAS REPLACED WITH THE EATON 19050T REAR AXLE. EATON 19050, 21065, AND 23070 SERIES AXLES USE 7/8" U-BOLTS FOR AXLE/SPRING MOUNTING. THE T175 REAR AXLE USED 3/4" U-BOLTS. SHOULD A T175 REAR AXLE REQUIRE SERVICE WHICH RESULTS IN U-BOLT REPLACEMENT, 7/8" U-BOLTS AND ATTACHING HARDWARE CAN BE USED AS REPLACEMENT PARTS. THE FOLLOWING SERVICE PROCEDURE AND PARTS INFORMATION LIST SHOULD BE UTILIZED WHEN INSTALLING 7/8" U-BOLTS AND MOUNTING HARDWARE ON T175 REAR AXLES. 7/8" U-BOLTS SHOULD BE INSTALLED AS A SET TO BOTH RIGHT AND LEFT SIDES OF THE AXLE. SERVICE PROCEDURE ----------------- TO REMOVE AND REPLACE THE REAR AXLE U-BOLT, ANCHOR PLATE, AND SPRING SADDLE, RAISE THE VEHICLE FRAME TO REMOVE WEIGHT FROM THE SPRING ASSEMBLY. PLACE JACK STANDS UNDER THE REAR AXLE TO SUPPORT THE AXLE WEIGHT. 1. REMOVE DUAL WHEEL ASSEMBLY USING A WHEEL DOLLY TO ALLOW ACCESS TO THE SPRING ASSEMBLY. 2. REMOVE U-BOLT NUTS (58). SEE FIGURE NO. 1. 3. REMOVE SHOCK ABSORBER BRACKET (4) IF EQUIPPED. SEE FIGURE NO. 2. 4. REMOVE U-BOLT ANCHOR PLATE (57). 5. REMOVE U-BOLT (54) AND SPACER (62). 6. INSTALL NEW SPACER (62) OVER THE CENTER BOLT. 7. INSTALL U-BOLTS INTO THE SPACER GROOVES. 8. INSTALL NEW U-BOLT ANCHOR PLATE (57) ONTO THE U-BOLTS. 9. INSTALL NEW SHOCK ABSORBER BRACKET (4) IF EQUIPPED. NOTICE: CLEAN ALL RUST AND DIRT FROM BRACKETS, SPACERS, AXLE TUBE, AND SPRINGS PRIOR TO REASSEMBLY. 10. INSTALL AND TIGHTEN THE U-BOLT NUTS DOWN TO THE ANCHOR PLATE. USE LONGER U-BOLT, P/N 8884242, IN REAR TO ATTACH THE SHOCK BRACKET WHEN RPO G56 OR G58 (HEAVY DUTY SPRINGS) AND RPO GYH OR G60 (AUXILIARY SPRINGS) AND RPO G68 (REAR SHOCK ABSORBERS) ARE ON THE TRUCK. NOTICE: DO NOT USE AIR OR ELECTRIC IMPACT WRENCH WHEN INSTALLING REAR SPRING AXLE U-BOLT PREVAILING TORQUE NUTS. 11. USING THE SEQUENCE ILLUSTRATED IN FIGURE NO. 3, A. WRENCH IN SEQUENCE TO 150 NM (110 LB FT). B. WRENCH THE SECOND SEQUENCE TO 300 NM (220 LB FT). C. WRENCH THE FINAL SEQUENCE TO 450 NM (330 LB FT). 12. REPLACE REAR DUAL WHEEL ASSEMBLY USING A WHEEL DOLLY AND REMOVE VEHICLE FROM SUPPORT. 13. CHECK U-BOLT NUT TORQUE AT 500 MILES AFTER INSTALLATION OF THE NEW U-BOLTS. MAINTENANCE RECOMMENDATIONS --------------------------- PER NORMAL MAINTENANCE PROCEDURES, THE OWNER MUST CHECK U-BOLT TORQUE AT 2,000 MILES AND AT 6,000 MILES; THEN CHECK THE U-BOLT NUT TORQUE EVERY 6,000 MILES OR 6 MONTHS, WHICHEVER OCCURS FIRST. PARTS INFORMATION ----------------- PART NUMBER DESCRIPTION QUANTITY ----------- ----------- -------- 15506611 ANCHOR PLATE 2 2082449 SADDLE 2 15503907 SHOCK ABSORBER BRACKET ASSEMBLY (IF EQUIPPED) 2 793295 U-BOLT 4 15544298 NUT (PREVAILING TORQUE) 8 2436169 WASHER 8 TRUCKS WITH RPO G56 OR G58 (HEAVY DUTY SPRINGS) AND RPO GYH OR G60 (AUXILIARY SPRINGS) AND RPO G68 (REAR SHOCK ABSORBERS) REQUIRE THE FOLLOWING: 15506611 ANCHOR PLATE 2 2082449 SADDLE 2 793295 U-BOLT 2 8884242 U-BOLT 2 15503907 SHOCK ABSORBER BRACKET ASSEMBLY 2 15544298 NUT (PREVAILING TORQUE) 8 2436169 WASHER 8 PARTS CAN BE PROCURRED THROUGH THE GENERAL MOTORS SERVICE PARTS OPERATION (GMSPO) ORDERING SYSTEM.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.