SMU - SECTION 3D - 'REAR SUSPENSION'. GMC Truck GMC Suburban

SUBJECT: SERVICE MANUAL UPDATE - SECTION 3D - "REAR SUSPENSION"

MODELS: 1991-95 CHEVROLET AND GMC TRUCK C/K MODELS

THIS BULLETIN UPDATES SECTION 3D "REAR SUSPENSION" OF THE 1991-95 C/K TRUCK SERVICE MANUALS. THE CURRENT SERVICE MANUAL INFORMATION HAS BEEN CHANGED TO INCLUDE TORQUE CALLOUTS FOR C3500 HD LEAF SPRING REPLACEMENT.

LEAF SPRING REPLACEMENT

1991-95 C3500 HD

REMOVE OR DISCONNECT (FIGURES 1 AND 2)

* RAISE VEHICLE ON A HOIST AND SUPPORT REAR AXLE INDEPENDENTLY TO RELIEVE TENSION ON LEAF SPRINGS.

1. U-BOLT NUTS AND WASHERS. 2. ANCHOR PLATE. 3. U-BOLTS AND SPACER. * LOOSEN SHACKLE TO SPRING NUT. 4. SHACKLE TO REAR BRACKET NUT, WASHERS, AND BOLT. 5. SHACKLE TO FRONT BRACKET NUT, WASHERS, AND BOLT. 6. SPRING ASSEMBLY FROM THE VEHICLE.

INSTALL OR CONNECT (FIGURES 1 AND 2)

1. SPRING ASSEMBLY TO THE VEHICLE. 2. SPRING TO FRONT BRACKET BOLT, WASHERS AND NUT. * DO NOT TIGHTEN. 3. SPRING TO REAR BRACKET BOLT, WASHERS, AND NUT. * DO NOT TIGHTEN. 4. SPACER AND "NEW" U-BOLTS TO THE TOP OF THE SPRING. 5. ANCHOR PLATE. 6. WASHERS AND NUTS.

TIGHTEN * NUTS IN SEQUENCE (FIGURE 3) * NUTS: 100 AND 200 MODELS 110 N.M 81 LB FT 300 MODELS WITHOUT DUAL REAR WHEELS OR 7.4L ENGINE 110 N.M 81 LB FT 300 MODELS WITH DUAL REAR WHEELS OR 7.4L ENGINE WITHOUT DUAL REAR WHEELS 148 N.M 109 LB FT 3500 HD 280 N.M 207 LB FT

ADJUST (FIGURE 4)

* THE SPRING HEIGHT TO OBTAIN A MEASUREMENT OF 182 MM (7 11/64 INCHES) BETWEEN THE TOP OF THE AXLE JOUNCE PAD AND THE BOTTOM SURFACE OF THE FRAME JOUNCE BRACKET.

TIGHTEN * LEAF SPRING TO BRACKET NUTS: C/K 1, 2, 3 125 N.M 92 LB FT 3500 HD 435 N.M 320 LB FT * LEAF SPRING TO SHACKEL NUT: C/K 1, 2, 3 110 N.M 81 LB FT 3500 HD 185 N.M 136 LB FT * SHACKLE TO BRACKET NUTS: C/K 1, 2, 3 110 N.M 81 LB FT 3500 HD 185 N.M 136 LB FT

FIGURES: 4 ATTACHMENTS: 0 CAPTIONS: FIGURE 1 - SINGLE AND DUAL WHEEL LEAF SPRINGS FIGURE 2 - AXLE ATTACHING COMPONENTS FIGURE 3 - U-BOLT TIGHTENING SEQUENCE FIGURE 4 - REAR AXLE TRIM HEIGHT

Object Number: 93912 Size: FS

Object Number: 81071 Size: FS

Object Number: 93137 Size: LF

Object Number: 93911 Size: MF

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.