FLUID LEAK NEAR FRONT WHEELS OR FRONT ENGINE. GMC Truck GMC K Pickup

REVISION: 08/17/98 DIVS INVL 1 5 7

THIS BULLETIN IS BEING REVISED TO ADD 1997 K TRUCK AXLE INFORMATION. PLEASE DISCARD CORPORATE BULLETIN NUMBER 86-43-06 (SECTION 4 - DRIVE AXLE). ______________________________________________________________________

SUBJECT: FLUID LEAK NEAR FRONT WHEELS OR FRONT ENGINE AREA (REPLACE FRONT AXLE OUTPUT SHAFT SEAL ASSEMBLY)

MODELS: 1997-98 CHEVROLET AND GMC K, L, AND T MODELS WITH 7.25 IN., 8.25 IN., AND 9.25 IN. FRONT AXLES

CONDITION:

SOME OWNERS MAY COMMENT ABOUT FLUID LEAKING ONTO THE GROUND NEAR THE FRONT WHEELS OR FRONT ENGINE AREA OR LEAKING ONTO THE SURROUNDING COMPONENTS.

CAUSE:

EXTREMELY COLD TEMPERATURES MAY CAUSE THE INSIDE OF THE DIFFERENTIAL SEALS TO BECOME BRITTLE AND THE SEALS MAY CRACK.

CORRECTION:

ENGINEERING HAS RELEASED A NEW SEAL WITH REVISED SEAL MATERIAL THAT IMPROVES THE COLD TEMPERATURE FLEX CAPABILITY. REPLACE THE SEALS WITH THE PART NUMBERS LISTED BELOW. REFER TO THE FRONT DRIVE AXLE SECTION IN THE APPROPRIATE SERVICE MANUAL.

FOR 1997 K TRUCK APPLICATIONS, USE THE FOLLOWING TABLE IN ORDER TO IDENTIFY SEAL USAGE:

IMPORTANT: THE OLD SEAL DESIGN (1997 AXLE P/N'S LISTED BELOW) CANNOT USE THE NEW SEAL DESIGN ON THESE P/N'S AND PRIOR YEARS. YOU MUST USE THE OLD SEAL DESIGN.

1997 (OLD SEAL DESIGN IN PRODUCTION THROUGH 1/97)

RING AXLE BROADCAST AXLE GEAR P/N CODE RATIO --------- -------- --------- ------ 8.25 INCH 26043583 ZWA (3:42) 8.25 INCH 26043584 ZWB (3:73) 9.25 INCH 26043586 ZWD (3:42) 9.25 INCH 26043587 ZWF (3:73) 9.25 INCH 26043588 ZWG (4:10) 9.25 INCH 26043589 ZWH (4:56)

1997 I (NEW SEAL DESIGN IN PRODUCTION AS OF 2/97)

RING AXLE BROADCAST AXLE GEAR P/N CODE RATIO --------- -------- --------- ------ 8.25 INCH 15742402 ZA1 (3:42) 8.25 INCH 15742404 ZB1 (3:73) 9.25 INCH 15742403 ZC1 (3:42) 9.25 INCH 15742405 ZD1 (3:73) 9.25 INCH 15742406 ZF1 (4:10) 9.25 INCH 15742407 ZH1 (4:56)

PARTS INFORMATION:

P/N DESCRIPTION AXLE SIZE QTY --- ------------ --------- ---

12471680 SEAL ASM., DIFF. SHAFT 7.25" 1 (T, L TRUCKS - RIGHT SIDE)

12471681 COVER ASM., DIFF. CARRIER SEAL 7.25" 1 (T, L TRUCKS - LEFT SIDE)

12471682 SEAL ASM., DIFF. SHAFT (K TRUCK) 8.25" 2

12471683 SEAL ASM., DIFF. SHAFT (K TRUCK) 9.25" 2

PARTS ARE CURRENTLY AVAILABLE FROM GMSPO.

WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

LABOR OPERATION DESCRIPTION LABOR TIME --------- ----------- ----------

F1440 SEAL, FRONT DIFFERENTIAL USE PUBLISHED LABOR OUTPUT SHAFT - REPLACE (RIGHT) OPERATION TIME

F1441 SEAL, FRONT DIFFERENTIAL USE PUBLISHED LABOR OUTPUT SHAFT - REPLACE (LEFT) OPERATION TIME

F1447 SEAL, FRONT DIFFERENTIAL USE PUBLISHED LABOR OUTPUT SHAFT - REPLACE (BOTH) OPERATION TIME

IMPORTANT: LABOR OPERATION IS CODED TO BASE VEHICLE COVERAGE IN THE WARRANTY SYSTEM.

FIGURES: 00 ATTACHMENTS: 00

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.