For 1990-2009 cars

# MISSED 2ND GEAR/SLIPS DIAGNOSIS

THE FOLLOWING IS A REVISED PROCEDURE FOR DIAGNOSING CONDITIONS OF NO SECOND GEAR, NO THIRD GEAR, SLIPPING SHIFTS OR LACK OF POWER IN SECOND GEAR. 1.VERIFY THE CONDITION A.CHECK AND CORRECT THE OIL LEVEL AS EXPLAINED IN THE SERVICE MANUAL B.SET THE T.V. CABLE TO SPECIFICATION AS EXPLAINED IN THE SERVICE MANUAL. C.ROAD TEST THE VEHICLE AND CHECK OIL PRESSURE USING THE SERVICE MANUAL PROCEDURE. 2.FOR CONDITIONS OTHER THAN NO SECOND GEAR, FOLLOW THE SERVICE MANUAL DIAGNOSIS PROCEDURE. 3.FOR A VERIFIED MISSED SECOND GEAR, CHECK FOR EVIDENCE OF INTERNAL OIL PRESSURE LEAKS AND EXCESSIVE WEAR OF INTERMEDIATE BAND AND DIRECT CLUTCH AS THE UNIT IS DISASSEMBLED. A.INSPECT THE OIL FILTER FOR ANY AREA ALLOWING SEDIMENT TO PASS THROUGH. REPLACE IF NECESSARY. B.CHECK THE GOVERNOR FOR STICKING WEIGHTS OR DAMAGED "O" RING SEAL. REPLACE IF NECESSARY. C.CHECK THE SERVO COVER AND GASKET FOR DAMAGE OR LEAKS. REPLACE IF NECESSARY. D.CHECK FOR MISSING OR DIRTY SERVO PISTON AND DAMAGED, MISSING OR LEAKING SERVO SEALS. ALSO, CHECK FOR A BLOCKED INTERMEDIATE APPLY PASSAGE IN THE CASE AND CASE COVER. E.CHECK FOR PROPER LENGTH OF SERVO APPLY PIN USING TOOLS J-28535-1 AND J-28535-4. SEE FIGURE 1. F.CHECK DESIGN OF ACCUMULATOR EXHAUST VALVE. SEE BUICK SERVICE BULLETIN 80-I-202, FILE GROUP 75 #36, DATED NOVEMBER 1980. G.CHECK THE ACCUMULATOR EXHAUST VALVE FOR PROPER SEATING OR POSSIBLE STICKING. ALSO, CHECK THE ACCUMULATOR EXHAUST SEAT FOR DEBRIS. H.CHECK TORQUE OF OIL PUMP/CONTROL VALVE TO DRIVEN SPROCKET SUPPORT BOLTS. IF TORQUE IS LESS THAN SPECIFICATIONS USE LOCTITE ON BOTH THREADS WHEN REINSTALLING. SEE FIGURE 2. I.CHECK THE OIL PUMP/CONTROL VALVE ASSEMBLY FOR STICKY OR LEAKING 1-2 VALVE AND/OR PRESSURE REGULATOR VALVE. ALSO, CHECK FOR BROKEN CASTING OR LEAKS AROUND THE SPACER PLATE OR GASKETS. J.CHECK FOR IMPROPERLY INSTALLED OR INCORRECT VALVE BODY SPACER PLATE AND GASKETS. IF IMPROPERLY INSTALLED OR INCORRECT THE VALVE BODY SPACER PLATE AND GASKETS MAY BLOCK THE GOVERNOR FEED TO THE 1-2 VALVE AND INTERMEDIATE BAND APPLY FEED ORIFICE. K.CHECK FOR MISSING OR STICKY NUMBER FOUR AND FIVE VALVE BODY CHECK BALLS. L.CHECK FOR MISSING OR DAMAGED 1-2 ACCUMULATOR PISTON, PIN OR SEALS. M.CHECK DRIVEN SPROCKET SUPPORT FOR BLOCKED PASSAGES AND CUT OR MISSING SEAL RINGS. N.CHECK FOR CORRECT COMBINATION OF NEW DESIGN AND PAST DESIGN DRIVEN SPROCKET, CASE TO CASE COVER GASKETS, CASE TO CASE COVER CENTER GASKET , AND DRIVEN SPROCKET TO DRIVEN SPROCKET SUPPORT THRUST WASHER. SEE BUICK SERVICE BULLETINS 80-T-2 AND 80-T-2A, FILE GROUP #75 NUMBERS 2 AND 2A. O.AIR CHECK THE DRIVEN SPROCET SUPPORT FOR CROSS CHANNEL LEAKS. THIS IS DONE BY BLOWING AIR IN EACH CHANNEL OF THE DRIVEN SPROCKET SUPPORT , ONE AT A TIME, AS SHOWN IN FIGURE 3. THE AIR SHOULD EXIT FROM ONLY THE CHANNEL IT IS BLOWN INTO. IF AIR EXITS FROM A CHANNEL OTHER THAN THE ONE BEING CHECKED THERE IS A CROSS CHANNEL LEAK AND THE DRIVEN SPROCKET SUPPORT MUST BE REPLACED. P.CHECK FOR MISPOSITIONED OR BROKEN INTERMEDIATE BAND. Q.CHECK THE DIRECT CLUTCH FOR LEAKING WELDS OR MISSING CLUTCH PLATES R.AIR CHECK THE DIRECT CLUTCH FOR A DAMAGED OR STICKY CHECK VALVE. S.CHECK THE DIRECT CLUTCH DRUM OUTSIDE DIAMETER MICROFINISH FOR DAMAGE. REPLACE THE DIRECT CLUTCH IF DAMAGE IS FOUND. T.CHECK THE DIRECT CLUTCH CENTER LIP SEAL FOR PROPER INSTALLATION AND CONDITION. SEE BUICK SERVICE BULLETIN 80-I-201, FILE GROUP #75, NUMBER 35, DATED NOVEMBER 1980. U.CHECK THE CASE AND CASE COVER FOR SIGNS OF DAMAGE AND/OR POROSITY. V.REASSEMBLE AS INSTRUCTED IN THE SERVICE MANUAL.

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.