INFO. ON TRANSMISSION OIL FILTER (SPIN ON)

SUBJECT: INFORMATION ON AUXILIARY TRANSMISSION OIL FILTER (SPIN ON) AND OIL FILTER ELECTRICAL CIRCUIT

MODELS: 1993-94 TOPKICK/KODIAK WITH OPTION MUZ

SOME TRUCKS ARE EQUIPPED WITH SPECIAL EQUIPMENT OPTION MUZ, A SPIN- ON TRANSMISSION OIL FILTER AND OIL FILTER TELLTALE LAMP. THIS SEO OPTION IS ONLY AVAILABLE WITH ALLISON AUTOMATIC TRANSMISSIONS, OPTIONS MF1 (AT545), ME3 (MT643D) AND ME5 (MT653DRD). THE ALLISON FILTER PROTECTS THE TRANSMISSION FROM IMPURITIES IN THE FLUID THAT ARE LARGER THAN 6 MICRONS.

PROCEDURE:

SERVICE PROCEDURES TO CHANGE SPIN-ON TRANSMISSION OIL FILTER:

NORMALLY, WHEN THE FILTER BECOMES PLUGGED, A DIFFERENTIAL PRESSURE SWITCH SENSES THE PRESSURE DROP ACROSS THE FILTER, CLOSES TO GROUND, AND CAUSES A "SERVICE TRANS FILTER" DASH TELLTALE LIGHT TO COME ON. IN THIS CASE,

1. REMOVE THE SPIN-ON TRANSMISSION FILTER AS INDICATED UNDER "SPIN- ON FILTER REPLACEMENT" IN SECTION 7A6 OF THE SERVICE MANUAL. WHEN AN ALLISON SPIN-ON FILTER IS USED, THE CHANGE INTERVAL IS UNTIL THE "SERVICE TRANS FILTER" LIGHT INDICATES THE FILTER IS CONTAMINATED OR UNTIL IT HAS BEEN IN SERVICE FOR THREE YEARS, WHICHEVER OCCURS FIRST. NO MILEAGE RESTRICTIONS APPLY. 2. INSPECT THE TRANSMISSION FLUID. REFERRING TO SECTION 7A6-2 OF THE SERVICE MANUAL, CHECK FOR FOAMING AND AERATING, WATER LEAKAGE, AND METAL PARTICLES. 3. IF INSPECTION REVEALS IMPURITIES IN THE TRANSMISSION FLUID, DRAIN THE TRANSMISSION FLUID AND FOLLOW PROCEDURES FOR SPECIFIC CONDITION IN SECTION 7A6. 4. INSTALL NEW SPIN-ON TRANSMISSION OIL FILTER AND REFILL THE TRANSMISSION FLUID. REFER TO SPIN-ON FILTER REPLACEMENT IN SECTION 7A6 OF THE SERVICE MANUAL. 5. THE PROCESS OF KEYING OFF THE TRUCK WILL RESET THE CIRCUIT AND TURN OFF THE "SERVICE TRANS FILTER" DASH TELLTALE LIGHT.

SERVICE PROCEDURES TO CHECK THE TRANSMISSION OIL FILTER CIRCUIT:

1. IF THE "SERVICE TRANS FILTER" DASH LIGHT REMAINS ON, THE TECHNICIAN SHOULD CHECK THE CIRCUIT. FIGURE 2 SHOWS THE WIRING SCHEMATIC OF THE TRANSMISSION OIL FILTER CIRCUIT. 2. DISCONNECT C142 AT THE B SIDE OF THE TRANSMISSION FILTER SWITCH. IF THE LIGHT GOES OUT, GO TO STEP 3. IF THE LIGHT STAYS ON, GO TO STEP 4. 3. IF THE LIGHT GOES OUT AFTER C142 IS DISCONNECTED, EITHER THE FILTER IS PLUGGED OR THE SENSOR IS SHORTED TO GROUND. REPLACE THE SPIN-ON TRANSMISSION OIL FILTER. IF THE LIGHT IS STILL ON AFTER THE FILTER AND TRANSMISSION FLUID HAS BEEN REPLACED, REPLACE THE SWITCH. 4. IF THE LIGHT STAYS ON AFTER C142 IS DISCONNECTED, THEN THERE IS A SHORT TO GROUND SOMEWHERE ON WIRE 1507, BETWEEN THE TELLTALE LAMP AND THE TRANSMISSION FILTER SWITCH. CHECK THE WIRE FOR A SHORT AND REPAIR THE WIRE.

PLEASE UPDATE SECTION 7A OF YOUR SERVICE MANUAL AS APPROPRIATE.

SERVICE PARTS INFORMATION:

P/N DESCRIPTION QTY 29510922 SPIN-ON TRANSMISSION OIL FILTER CANNISTER AND SEAL 1 29501991 DIFFERENTIAL PRESSURE SWITCH 1 29501482 TRANSMISSION OIL FILTER ASSEMBLY 1 (INCLUDES BASE, CANNISTER, SWITCH AND 8" LEADS)

PARTS ARE CURRENTLY AVAILABLE FROM GMSPO.

WARRANTY INFORMATION:

LABOR OPERATION NUMBER: K5281

FIGURES: 3

CAPTIONS: FIGURE 1 - LOCATION OF TRANSMISSION OIL FILTER ASSEMBLY (46710101) FIGURE 2 - WIRING SCHEMATIC OF THE TRANSMISSION OIL FILTER ELECTRICAL CIRCUIT (46710102) FIGURE 3 - EXPANDED VIEW OF TRANSMISSION OIL FILTER ASSEMBLY (46710103)

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.

COPYRIGHT 1994 GENERAL MOTORS CORPORATION. ALL RIGHTS RESERVED.