DIESEL HIGH OR LATE UPSHIFT NEW VRV /400 TRANSMISSION

COMMENTS REGARDING HIGH OR LATE UPSHIFTS IN 1982 "C-K-P" TRUCKS EQUIPPED WITH 6.2L DIESEL ENGINES AND THM 400 AUTOMATIC TRANSMISSIONS MAY BE THE RESULT OF THE VACUUM REGULATOR VALVE (VRV) CALIBRATION. THIS CONDITION MAY BE CORRECTED BY REPLACING THE VALVE WITH A NEW VALVE, P/N 14057219. THE NEW VALVE ENTERED PRODUCTION AT THE ASSEMBLY PLANTS IN MARCH, 1982 THE VRV SHOULD BE VERIFIED AS THE CAUSE OF THIS CONDITION USING THE FOLLOWING PROCEDURE: 1. IDENTIFY WHICH VALVE (OLD OR NEW) IS ON THE ENGINE. REFER TO FIGURE ONE (1). A. OLD VALVE-ROTATING CAM IS GREEN COLOR. P/N 14033982 IS CAST INTO THE VALVE. B. NEW VALVE-ROTATING CAM IS ORANGE COLOR. P/N 14057219 IS WHITE LETTERED ON FACE OF VALVE. 2. IF THE VALVE HAS A GREEN ROTATING CAM, REMOVE THE VALVE. IF THE ROTATING CAM IS ORANGE, GO TO STEP 5. 3. INSTALL A NEW VALVE, P/N 14057219. 4. FOLLOW SERVICE MANUAL PROCEDURES (6C6-2) BUT SET THE VALVE TO 27 KPA. 5. IF THE VALVE HAS AN ORANGE ROTATING CAM (P/N 14057219), CHECK FOR A CORRECT SETTING OF 27 KPA USING SERVICE MANUAL PROCEDURES. (SEE ILLUSTRATION)

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.