FLUID LEAK OR MISSING SPEED SENSOR BORE PLUG. GMC Truck GMC K Pickup

SUBJECT: MISSING OR FLUID LEAKING-OUTPUT SPEED SENSOR BORE PLUG (INSTALL NEW PLUG)

MODELS: 1994 CHEVROLET AND GMC K-TRUCKS WITH 4WD ONLY

THIS BULETIN HAS BEEN REVISED TO UPDATE THE SERVICE PROCEDURE. PLEASE DISCARD CORPORATE BULLETIN #377145.

CONDITION:

THE OUTPUT SPEED SENSOR BORE PLUG MAY FALL OUT OR FLUID MAY LEAK PAST THE PLUG.

ON SOME 1994 4L80-E 4WD MODELS, THE T.O.S.S. HAS BEEN REMOVED AND A PLATED STEEL BORE PLUG IS INSTALLED. THE OUTPUT SPEED SENSOR RELUCTOR RING IS ALSO ELIMINATED ON THESE MODELS. THE OUTPUT SPEED/VEHICLE SPEED IS OBTAINED FROM THE OUTPUT SPEED SENSOR IN THE TRANSFER CASE.

BEGINNING ON JANUARY 21, 1994 (JULIAN DATE 021), ALL 1994 4L80-E 4WD MODELS WILL HAVE A SPEED SENSOR INSTALLED IN THE OUTPUT SPEED SENSOR BORE. THE SPEED SENSOR IS USED AS A PLUG, IT WILL NOT FUNCTION ELECTRICALLY.

CORRECTION:

WHEN SERVICING A TRANSMISSION FOR A LEAKING OR MISSING SPEED SENSOR BORE PLUG, REPLACE THE PLUG WITH A SPEED SENSOR ASSEMBLY. REFER TO THE APPROPRIATE SERVICE MANUAL FOR PROPER REPAIR PROCEDURES.

WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

LABOR OP. DESCRIPTION LABOR TIME K6312 SENSOR USE PUBLISHED ASSEMBLY SPEED LABOR OPERATION OUTPUT-REPLACE TIME

SERVICE PARTS INFORMATION:

PART NUMBER DESCRIPTION 8685042 SPEED SENSOR ASSEMBLY

PARTS ARE CURRENTLY AVAILABLE THROUGH GMSPO.

FIGURES: 1

Object Number: 81920 Size: FS

GENERAL MOTORS BULLETINS ARE INTENDED FOR USE BY PROFESSIONAL TECHNICIANS, NOT A "DO-IT-YOURSELFER." THEY ARE WRITTEN TO INFORM THOSE TECHNICIANS OF CONDITIONS OCCURRING 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 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.