For 1990-2009 cars

# NO TCC RELEASE 125C AUXILIARY VALVE BODY GASKET

1981-84 "A","J" AND"X" SERIES EQUIPPED WITH A THM 125C TRANSAXLE MAY EXPERIENCE POOR FUEL ECONOMY AND/OR ENGINE CHUGGLE OR SHUDDER DUE TO THE TORQUE CONVERTER CLUTCH (TCC) EITHER FAILING TO RELEASE OR APPLY. THIS MAY BE CAUSED BY A MISSING OR MISPOSITIONED ORIFICE CUP PLUG IN THE AUXILIARY VALUE BODY ASSEMBLY, OR AN ERODED GASKET ON THE AUXILIARY VALVE BODY COVER. DURING SEPTEMBER, 1983 ALL THM 125-C TRANSMISSIONS WERE BUILT WITH A NEW AUXILIARY VALVE BODY AND AUXILIARY VALVE BODY GASKET. THE NEW AUXILIARY VALVE DOES NOT HAVE AN ORIFICE PLUG HOLE (FIGURE 1). THE AUXILIARY VALVE BODY GASKET IS MADE OUT OF A NEW MATERIAL AND HAS THREE HOLES MADE LARGER (FIGURE 2). THE CHANGES TO THE GASKET ELIMINATE A NO TORQUE CONVERTER RELEASE (TCC) OR NO (TCC) APPLY CONDITION THAT RESULTED FROM INCORRECT CUP PLUG, MISPOSITIONED CUP PLUG OR ERODING OF THE GASKET. NOTE: THE ONLY INTERCHANGEABLE PART IS THE AUXILIARY VALVE BODY COVER (FIGURE 3). THE NEW AUXILIARY VALVE BODY GASKET MUST BE USED WITH THE NEW AUXILIARY VALVE BODY. THE PAST AUXILIARY VALVE BODY GASKET MUST BE USED WITH THE PAST AUXILIARY VALVE BODY. WHEN SERVICING ANY MODEL THM 125-C TRANSMISSION AUXILIARY VALVE BODY REFER TO THE FOLLOWING PROCEDURE: 1. IDENTIFY THE AUXILIARY VALVE BODY BEING SERVICED (PAST OR NEW) SEE FIGURE 1. 2. IF THE PAST AUXILIARY VALVE BODY IS BEING SERVICED REFER TO CHART 1. IF THE NEW AUXILIARY VALVE BODY IS BEING SERVICED REFER TO CHART 2.

CHART 1 PART BEING REPLACED PART NUMBER AUXILIARY VALVE BODY COVER GASKET 8653947 AUXILIARY VALVE BODY COVER 8643645 AUXILIARY VALVE BODY ORIFICE PLUG 8623796 AUXILIARY VALVE BODY (PAST DESIGN NEW AUXILIARY VALVE BODY NOT SERVICED) MUST BE USED, ORDER SERVICE PACKAGE 8653946. CHART 2 PART BEING REPLACED PART NUMBER AUXILIARY VALVE BODY COVER GASKET 8643863 AUXILIARY VALVE BODY COVER 8643645 AUXILIARY VALVE BODY MODELS REFER TO CHART 3. BF,BL,CE,CA,CB,CF,CL,CK,CT,CC,PE,PD,PG, 8653946 SERVICE PACKAGE PJ,PW,PF EM,EN,EW,HC,HS,HV,HY,OP 8653945 SERVICE PACKAGE SERVICE PACKAGE 8653946 CONTAINS: 1 8643865 AUXILIARY VALVE BODY 1 8643863 GASKET AUXILIARY VALVE BODY 1 8643645 COVER AUXILAIRY VALVE BODY SERVICE PACKAGE 8653945 CONTAINS: 1 8643864 BODY AUXILIARY VALVE 1 8643863 GASKET AUXILIARY VALVE BODY COVER 1 8643645 COVER AUXILIARY VALVE BODY ONLY THE AUXILIARY VALVE BODY COVER, AUXILIARY VALVE BODY GASKET, AND AUXILIARY VALVE BODY ORIFICE PLUG CAN BE ORDERED SEPARATELY. SERVICE PROCEDURE: 1. PREFORM TCC DIAGNOSIS AS OUTLINED IN SERVICE INFORMATION MANUAL. IF DIAGNOSIS INDICATES AN AUXILIARY VALVE BODY CONDITION, REMOVE THE AUXILIARY VALVE BODY FROM THE TRANSAXLE FOLLOWING PROCEDURES OUTLINED IN THE SERVICE MANUAL. 2. INSPECT THE AUXILIARY VALVE BODY TO DETERMINE IF IT IS THE ORIGINAL AND/OR EROSION AROUND HOLE NUMBER 1 IN FIG. 2. IF GASKET IS ERODED REPLACE THE AUXILIARY VALVE BODY COVER ALONG WITHT THE REQUIRED GASKET. IF THE AUXILIARY VALVE BODY HAS THE HOLE USED FOR AN ORIFICE CUP PLUG(REFER TO FIG.1), WHETHER OR NOT THE ORIFICE CUP PLUG IS PRESENT, PROCEED TO STEP 3. IF NO HOLE IS USED, PROCEED TO STEP 4. 3.ORIGINAL AUXILIARY VALVE BODY CONDITION CORRECTION A. ORIFICE CUP PLUG AND REPLACE GASKET WITH P/N 8653947 AND AUXILIARY VALVE BODY COVER WITH P/N 8643645. OKAY. GASKET ERODEED AT HOLE #1. B. AUXILIARY VALVE BODY REPLACE ORIFICE PLUG WITH P/N8623796 AND GASKET OKAY. AND GASKET WITH P/N 8643239. TO ORIFICE CUP PLUG REPLACE THE ORIFICE PLUG, REMOVE MISPOSITIONED OR MISSING. USING A 7/32 SCREW EXTRACTOR. APPLY LOCTITE TO THE NEW PLUG. START THE NEW PLUG USING A 5/16 PUNCH AND SEAT FLUSH WITH THE WALL USING A 3/8 PUNCH. C. ORIFICE PLUG AND REPLACE AUXILIARY VALVE BODY WITH GASKET OKAY. SERVICE KIT P/N 8653946. THE AUXILIARY VALVE BODY IN THIS KIT DOES NOT CONTAIN TCC CONTROL AND REGULATING VALVE, OR REGULATOR SPRING. IF NEEDED, THESE PARTS ARE AVAILABLE SEPARATELY UNDER THE FOLLOWING PART NUMBERS: VALVE,TCC CONTROL P/N 8637089 VALVE,TCC REGULATOR P/N 8637090 SPRING,TCC REGULATOR P/N 8637888 4. NEW AUXILIARY VALVE BODY A. GASKET ERODED AT HOLE REPLACE GASKET P/N 8643863 AND #1. AXUILIARY VALVE COVER P/N 8643645. BODY OKAY. B. GASKET OKAY. REPLACE AUXILIARY VALVE BODY WITH SERVICE KIT P/N 8653946. WHEN PREFORMING THE LISTED REPAIRS, BE SURE THE CORRECT GASKET IS USED. ALL GMWDD STOCK OF BOTH ORIGINAL AND NEW TYPE GASKET ARE NOW MADE USING THE NEW MATERIAL. THE NEW COVER IS USED TO SERVICE BOTH DESIGNS.

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.