TRANS. EXCHANGE PROGRAM FUNCTIONAL CHARACTERISTICS

THE THM 440-T4 IS A 4-SPEED AUTOMATIC TRANSAXLE WITH OVERDRIVE BEING OFFERED AS AN OPTION ON LATE MODEL "A" SERIES STATION WAGONS. IT IS ENGINE VACUUM MODULATED FOR SHIFT FEEL AND T.V. CABLE CONTROLLED FOR SHIFT TIMING. THE LOCKING TORQUE CONVERTER CLUTCH (TCC) PROVIDES A DIRECT DRIVE COUPLING FROM ENGINE TO TRANSMISSION FOR GREATER FUEL ECONOMY. TCC OPERATION BY GEAR IS AS SHOWN BELOW: GEAR TCC OPERATION 4TH ALWAYS ENGAGED 3RD CAN BE ENGAGED OR DISENGAGED 2ND NEVER ENGAGED 1ST NEVER ENGAGED THE 440-T4 IS SUBJECT TO MORE FREQUENT SHIFTING THAN THE STANDARD 3-SPEED AUTOMATIC AT SPEEDS BETWEEN THIRTY (30) AND SIXTY (60) MPH. THIS SHIFTING IS NORMAL AND IS DUE TO THE ADDITIONAL 4TH OVERDRIVE GEAR AND 3RD GEAR TCC OPERATION. THE ECM IS PROGRAMMED TO ENGAGE OR DISENGAGE TCC IN 3RD GEAR DEPENDING ON VEHICLE SPEED AND THROTTLE POSITION SO THAT PEAK FUEL ECONOMY AND VEHICLE PERFORMANCE CAN BE MAINTAINED. TRANSMISSION EXCHANGE PROGRAM A NATIONWIDE TRANSMISSION EXCHANGE PROGRAM IS NOW IN EFFECT FOR THE 440-T4 TRANSMISSION. THIS PROGRAM IS AVAILABLE TO ALL CHEVROLET DEALERSHIPS AND WILL BE RUN THROUGH THE BALANCE OF THE 1984 MODEL YEAR AND INTO THE 1985 MODEL YEAR UNTIL A MINIMUM OF ONE HUNDRED (100) TRANSMISSIONS HAVE BEEN EXCHANGED. WHEN A SUBJECT VEHICLE IS BROUGHT IN FOR TRANSMISSION RELATED SERVICE, THE STEPS BELOW SHOULD BE FOLLOWED: -PERFORM MINIMUM AND MAXIMUM TRANSMISSION LINE PRESSURE CHECKS. RECORD ALL READINGS. CHECK T.V. CABLE ADJUSTMENT, AND CHECK THE FLUID LEVEL. -DO NOT DISASSEMBLE THE TRANSMISSION, OR EVEN REMOVE THE PAN IN AN ATTEMPT TO REPAIR A LEAK. IF THE TRANSMISSION LEAKS, CLEAN THE POTENTIAL LEAK AREA, COVER THE AREAA WITH LEAK DETECTING POWDER AND MARK THE LEAK AREA ON THE TRANSMISSION. -CHECK THE ENTIRE VACUUM SYSTEM TO THE MODULATOR CANISTER ON THE TRANSMISSION. PROPER ENGINE OPERATION, ESPECIALLY WITH REGARD TO VACUUM, IS CRITICAL FOR PROPER TRANSMISSION FUNCTION. THE VACUUM LINES SHOULD BE PROPERLY CONNECTED AND INSPECTED FOR CUTS AND KINKS. VACUUM PRESSURE SHOULD BE CHECKED AS INSTRUCTED IN THE SERVICE MANUAL. -IF AFTER THE ABOVE CHECKS AN EXCHANGE TRANSMISSION IS REQUIRED, CONTACT YOUR AREA SERVICE MANAGER AND PROVIDE THE FOLLOWING INFORMATION: 1. VEHICLE IDENTIFICATION NUMBER. 2. TRANSMISSION SERIAL NUMBER (LOCATED ON RIVETED PLATE UNDER TRANSMISSION NEAR RH AXLE OPENING.) 3. MILEAGE 4. DEALER CODE 5. CONDITION/COMMENT 6. PRESSURE READINGS. -THE AREA SERVICE MANAGER WILL ARRANGE FOR A REPLACEMENT TRANSMISSION AND WILL PROVIDE YOU WITH A TRANSMISSION EXCHANGE REQUEST NUMBER. THE REPLACEMENT TRANSMISSION WILL BE AIR FREIGHTED TO YOU. -A HYDRAMATIC PRODUCT REPRESENTATIVE MAY TELEPHONE TO ARRANGE A PERSONAL INSPECTION OF THE TRANSMISSION IN THE VEHICLE AND/OR TO AUDIT THE VEHICLE AFTER THE NEW UNIT IS INSTALLED. IF YOU HAVE NOT RECEIVED A CALL FROM THE PRODUCT REPRESENTATIVE BY THE TIME THE REPLACEMENT TRANSMISSION ARRIVES, CONTINUE WITH THE STEPS BELOW; DO NOT WAIT TO BE CONTACTED. -REMOVE THE TRANSMISSION FROM THE VEHICLE AND INSTALL THE REPLACEMENT TRANSMISSION AS INSTRUCTED IN THE SERVICE MANUAL. THE TRANSMISSION EXCHANGE REQUEST NUMBER WHICH WAS PROVIDED BY YOUR AREA SERVICE MANAGER MUST BE WRITTEN ON THE TRANSMISSION BELL HOUSING OF THE TRANSMISSION WITH A BLACK MARKER. ATTACH A TAG TO THE BELL HOUSING SHOWING THE VIN, MILEAGE, LINE PRESSURE READINGS, EXCHANGE REQUEST NUMBER, AND THE COMMENT/CONDITION. DRAIN THE OIL THROUGH THE COOLER LINE OPENINGS AS MUCH AS POSSIBLE AND INSTALL ALL PLASTIC PLUGS FROM THE REPLACEMENT UNIT IN THEIR PROPER LOCATION ON THE TRANSMISSION BEING RETURNED. PLACE THE TRANSMISSION IN THE PLASTIC BAG THAT WAS REMOVED FROM THE NEW TRANSMISSION AND REPACK IT IN THE ORIGINAL SHIPPING CASE, ENSURING THAT THE CASE IS SECURELY SEALED OR STRAPPED. -WHEN THE TRANSMISSION IS READY FOR RETURN SHIPMENT TO HYDRAMATIC, CONTACT GAIL MILLER, ASSISTANT TRAFFIC MANAGER, HYDRMATIC WARREN PLANT, (313) 575-1818, WHO WILL MAKE THE SHIPPING ARRANGEMENTS TO AIR FREIGHT THE UNIT BACK TO HYDRAMATIC.

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.