STALL/SURGE AT STOP OR WHEN SHIFTED TO DRIVE. GMC Truck GMC P42 Commercial Chassis 1998

SUBJECT: STALLS/SURGE AT STOP OR WHEN SHIFTED TO DRIVE OR REVERSE/ TRANSMISSION SLIPS (REPAIR TRANSMISSION AUXILIARY OIL COOLER LINE OR REPLACE TRANSMISSION TORQUE CONVERTER)

MODELS: 1998 CHEVROLET AND GMC C/K, G, P TRUCKS WITH HYDRA-MATIC 4L80E TRANSMISSION (RPO MT1)

CONDITION:

SOME OWNERS MAY COMMENT ON AN ENGINE STALL OR A SLIGHT SURGE AT A STOP OR WHEN THE TRANSMISSION IS SHIFTED INTO DRIVE OR REVERSE.

CAUSE:

THE ABOVE CONDITIONS MAY HAVE MORE THAN ONE CAUSE: 1. THE TRANSMISSION AUXILIARY OIL COOLER LINE MAY BE KINKED DUE TO IMPROPER INSTALLATION. 2. THE TRANSMISSION OIL COOLER, (LOCATED IN THE RADIATOR), MAY BE PLUGGED WITH DEBRIS, OR 3. THE TRANSMISSION TORQUE CONVERTER MAY HAVE AN INTERNAL FAILURE.

CORRECTION:

INSPECT THE AUXILIARY COOLER LINES FOR KINKS OR DAMAGE, PERFORM AN OIL COOLER FLOW TEST AND REPAIR AS NECESSARY.

SERVICE PROCEDURE - PERFORM THE TRANSMISSION OIL COOLER FLOW TEST IN CORPORATE BULLETIN 77-71-59 OR IN THE APPROPRIATE SERVICE MANUAL.

* IF THE FLUID FLOW IS LESS THAN 2 QUARTS IN 30 SECONDS, INSPECT THE AUXILIARY OIL COOLER LINES FOR KINKS OR DAMAGE. REPAIR AS NECESSARY.

* IF THE AUXILIARY OIL COOLER LINES ARE NOT THE CAUSE, INSPECT FOR A PLUGGED TRANSMISSION OIL COOLER IN THE RADIATOR OR A PLUGGED AUXILIARY OIL COOLER. REPAIR AS NECESSARY.

* IF THERE IS NO PROBLEM WITH THE AUXILIARY OIL COOLER LINES OR THE OIL COOLER, REPLACE THE TRANSMISSION TORQUE CONVERTER.

WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

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

K5391 UPPER, LINE AND/OR FITTING, USE PUBLISHED LABOR TRANSMISSION OIL COOLER OPERATION TIME

K5393 LOWER, LINE AND/OR FITTING, USE PUBLISHED LABOR TRANSMISSION OIL COOLER OPERATION TIME

K5290 COOLER, TRANSMISSION OIL USE PUBLISHED LABOR OPERATION TIME

K7020 CONVERTER ASSEMBLY, USE PUBLISHED LABOR TRANSMISSION OPERATION TIME

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.