MANUAL TRANSAXLE SHIFT DIAGNOSTIC AID

THE FOLLOWING INFORMATION IS PUBLISHED AS AN AID IS RESOLVING DIFFICULT SHIFT CONDITIONS IN 1980-81 CITATIONS. ADJUSTMENT FIRST AND FOREMOST SHIFT CABLE ADJUSTMENT MUST BE CHECKED, ALONG WITH TORQUE OF ATTACHING PARTS. THE ADJUSTMENT PROCEDURE IS OUTLINED IN THE SERVICE MANUAL SECTION 7B-5. SHOULD THE CONDITION BE A DIFFICULTY IN 3-2 DOWNSHIFT, THE FOLLOWING REVISION TO THE ADJUSTMENT PROCEDURE MAY BE APPLICABLE. (1) HAVE AN ASSISTANT HOLD THE SHIFT LEVER IN FIRST AND PUSH THE LEVER FORWARD AND OUTBOARD (LEFT) TO REMOVE ALL LASH IN THE SHIFTER ASSEMBLY. (2) THEN LOOSEN THE NUT (E) ON SELECT LEVER (D) (SEE ILLUSTRATION). (3) GRASP LEVER (D) WITH THE FINGERS AND TURN CLOCKWISE (OUTBOARD) WHEN VIEWED FROM THE FRONT OF THE VEHICLE. (4) AT THE SAME TIME, PUSH THE CABLE (B) INBOARD WITH THE THUMB AND TIGHTEN NUT (E) TO 20-35 N.M. 1-2 SHIFT FORK ON 1980 VEHICLES HAVING RECURRING DIFFICULTY IN 1-2 SHIFT WHICH CABLE ADJUSTMENT APPEARS TO IMPROVE FOR A SHORT PERIOD OF TIME AND THE TRANSAXLE BUILD CODE IS PRIOR TO XOD29 (APRIL 29, 1980) THERE IS PROBABILITY OF A WORN 1-2 SHIFT FORK AS OUTLINED IN DEALER INFORMATION BULLETIN 80-I-62. DIFFICULT N-1 SHIFT AND RATTLING NOISE DIFFICULT NEUTRAL TO FIRST SHIFT, ESPECIALLY WHEN THE INPUT SHAFT HAS BEEN ALLOWED TO SPIN DOWN TO ZERO, CAN BE CAUSED BY THE INPUT GEAR BEARING CREEPING OFF ITS SEAT, INCREASING THE BEARING PRELOAD. TRANSAXLES PRODUCED AFTER BUILD CODE XOS16 (11/16/79) HAVE A NEW INPUT GEAR P/N 14020899 WITH .07 SMALLER JOURNAL WHICH WILL ALLOW THE BEARING TO FLOAT FREELY. IN AN ADVANCED STAGE, THIS CONDITION MAY BE ACCOMPANIED BY A RATTLING OR MARBLE LIKE NOISE WHICH INDICATES EMINENT BEARING FAILURE. * 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.