NO REVERSE, OR PERCEIVED LACK OF POWER IN 2ND GEAR. Chevrolet S10 Pickup

SUBJECT: NO REVERSE, OR PERCEIVED LACK OF POWER (TIE UP) IN 2ND GEAR (SHIFT LINKAGE ADJUSTMENT PROCEDURE)

MODELS: 1994 CHEVROLET AND GMC TRUCK S/T, M/L, C/K 1,2 MODELS 1994 OLDSMOBILE BRAVADA WITH THE 4L60E AUTOMATIC TRANSMISSION (RPO M30) AND A ROD STYLE SHIFT LINKAGE

CONDITION:

SOME OWNERS MAY EXPERIENCE A LOSS OF REVERSE OR A TIE-UP (PERCEIVED LACK OF POWER) IN 2ND GEAR. INSPECTION OF THESE TRANSMISSIONS OFTEN INDICATES HEAVY WEAR AND EVIDENCE OF HIGH HEAT ON THE LOW-REVERSE CLUTCH AND 2-4 BAND.

CAUSE:

THE TRANSMISSION SHIFT LINKAGE MAY BE IMPROPERLY ADJUSTED (THE MANUAL VALVE IS NOT PROPERLY POSITIONED IN RELATIONSHIP TO THE "PRNDL" POSITION). THIS MAY PREVENT THE LOW-REVERSE CLUTCH APPLY CIRCUIT FROM EXHAUSTING AFTER A SHIFT FROM PARK OR REVERSE TO A FORWARD RANGE. IF THE LOW-REVERSE CLUTCH REMAINS PARTIALLY APPLIED, A TIE-UP MAY OCCUR WHEN THE TRANSMISSION SHIFTS FROM FIRST TO SECOND GEAR. THIS COULD RESULT IN LOW-REVERSE CLUTCH AND 2-4 BAND FAILURE.

CORRECTION:

THE TRANSMISSION SHIFT LINKAGE MUST BE PROPERLY ADJUSTED FOLLOWING REPAIR OR REPLACEMENT OF THE TRANSMISSION OR IF THE "PRNDL" INDICATOR DOES NOT MATCH THE ACTUAL TRANSMISSION RANGE. THE FOLLOWING PROCEDURE MUST BE FOLLOWED WHEN ADJUSTING THE ROD STYLE LINKAGE ON A 4L60E EQUIPPED VEHICLE:

-S/T MODELS USE ADJUSTMENT PROCEDURE #1 -M/L MODELS USE ADJUSTMENT PROCEDURE #2 -C/K MODELS USE ADJUSTMENT PROCEDURE #3

ADJUSTMENT PROCEDURE #1 APPLIES TO 1994 S/T VEHICLES WITH 4L60E TRANSMISSION:

1. LINKAGE ADJUSTMENT MUST BE PERFORMED AT THE TRANSMISSION PRIOR TO ANY "PRNDL" INDICATOR ADJUSTMENT AT THE STEERING COLUMN. 2. FULL WEIGHT OF VEHICLE MUST BE ON WHEELS (CURB HEIGHT). DO NOT USE A FRAME HOIST TO RAISE THE VEHICLE FOR THIS PROCEDURE. MANDATORY THAT VEHICLE BE RAISED ON A TWIN POST HOIST OR UTILIZE AN ALIGNMENT RACK. 3. POSITION THE STEERING COLUMN SHIFT LEVER IN THE NEUTRAL GATE NOTCH. (DO NOT USE THE INDICATOR TO FIND NEUTRAL.) 4. LOOSEN THE BOLT (2) IN THE SWIVEL (4) THAT CLAMPS THE SHIFT ROD (1) TO THE TRANSMISSION EQUALIZER LEVER (3). MAKE SURE THAT THE SHIFT ROD MOVES FREELY IN THE SWIVEL. 5. SET TRANS LEVER (5) IN NEUTRAL DETENT. OBTAIN NEUTRAL DETENT BY INDEXING TRANS LEVER ALL THE WAY CLOCKWISE TO "PARK", THEN COUNTER-CLOCKWISE TWO DETENTS TO "NEUTRAL". (ALTERNATE PROCEDURE IS ROTATE TRANS LEVER COUNTER-CLOCKWISE ALL THE WAY TO "L1", THEN ROTATING IT CLOCKWISE FOUR DETENTS.) 6. MAKE SURE THAT TRANS CONTROL LEVER (3) IS FULLY SEATED IN TRANS LEVER (5). HOLD THE ROD (1) TIGHTLY IN THE SWIVEL (4). TIGHTEN CLAMP SCREW (2) AGAINST ROD (1) TO 25 N.M (18 LBS. FT.). MAKE SURE THE ROD DOES NOT MOVE IN THE SWIVEL WHILE TIGHTENING THE SCREW. 7. VERIFY PROPER ADJUSTMENT:

- WHEN MOVING THE TRANSMISSION SHIFT LEVER IN EITHER DIRECTION, ALL DETENT POSITIONS WILL BE ATTAINABLE WITHOUT A BINDING CONDITION PRESENT. - WITH THE KEY ON AND THE SHIFT LEVER IN "REVERSE", THE KEY WILL NOT BE REMOVABLE AND THE STEERING COLUMN WILL NOT BE LOCKED. - WITH THE KEY IN THE LOCK POSITION AND THE SHIFT LEVER IN THE "PARK" POSITION, THE KEY WILL BE REMOVABLE, THE STEERING WHEEL WILL BE LOCKED, AND THE SHIFT LEVER WILL NOT DISENGAGE "PARK". IN ADDITION, VERIFY THAT THE VEHICLE IS HELD STATIONARY IN "PARK". - THE ENGINE MUST START IN THE "NEUTRAL" OR "PARK" POSITIONS ONLY. ADJUST NEUTRAL SAFETY SWITCH AS REQUIRED. - VERIFY THAT SHIFT INDICATOR POSITION MATCHES ACTUAL TRANSMISSION RANGE. ADJUST "PRNDL" SWITCH AS REQUIRED.

***INSERT FIGURE 1 HERE***

ADJUSTMENT PROCEDURE #2 APPLIES TO 1994 M/L VEHICLES WITH 4L60E TRANSMISSION:

1. LINKAGE ADJUSTMENT MUST BE PERFORMED AT THE TRANSMISSION PRIOR TO ANY "PRNDL" INDICATOR ADJUSTMENT AT THE STEERING COLUMN. 2. FULL WEIGHT OF VEHICLE MUST BE ON WHEELS (CURB HEIGHT). DO NOT USE A FRAME HOIST TO RAISE THE VEHICLE FOR THIS PROCEDURE. MANDATORY THAT VEHICLE BE RAISED ON A TWIN POST HOIST OR UTILIZE AN ALIGNMENT RACK. 3. POSITION THE STEERING COLUMN SHIFT LEVER IN THE NEUTRAL GATE NOTCH. (DO NOT USE THE INDICATOR TO FIND NEUTRAL). 4. LOOSEN THE BOLT (2) FROM THE SWIVEL (4) THAT CLAMPS THE SHIFT ROD (1) TO THE TRANSMISSION EQUALIZER LEVER (3). MAKE SURE THE ROD SLIDES FREELY IN THE SWIVEL. 5. SET TRANS LEVER (5) IN NEUTRAL DETENT. OBTAIN NEUTRAL DETENT BY INDEXING TRANS LEVER ALL THE WAY CLOCKWISE TO "PARK", THEN COUNTER-CLOCKWISE TWO DETENTS TO "NEUTRAL". (ALTERNATE PROCEDURE IS ROTATE TRANS LEVER COUNTER-CLOCKWISE ALL THE WAY TO "L1", THEN ROTATING IT CLOCKWISE FOUR DETENTS.) 6. MAKE SURE THAT TRANSMISSION EQUALIZER LEVER (3) IS FULLY SEATED IN TRANS LEVER (5). HOLD THE SHIFT ROD (1) TIGHTLY IN THE SWIVEL (4) AND TIGHTEN THE BOLT (2) TO 25 N.M (18 LBS. FT.). DO NOT ALLOW THE ROD TO SLIDE IN THE SWIVEL WHILE TIGHTENING. 7. VERIFY PROPER ADJUSTMENT:

***INSERT FIGURE 2 HERE***

ADJUSTMENT PROCEDURE #3 APPLIES TO 1994 C/K VEHICLES WITH 4L60E TRANSMISSION:

1. LINKAGE ADJUSTMENT MUST BE PERFORMED AT THE LOWER END OF THE STEERING COLUMN PRIOR TO ANY "PRNDL" INDICATOR ADJUSTMENT. 2. FULL WEIGHT OF VEHICLE MUST BE ON WHEELS (CURB HEIGHT). DO NOT USE A FRAME HOIST TO RAISE THE VEHICLE FOR THIS PROCEDURE. MANDATORY THAT VEHICLE BE RAISED ON A TWIN POST HOIST OR UTILIZE AN ALIGNMENT RACK. 3. POSITION THE STEERING COLUMN SHIFT LEVER IN THE NEUTRAL GATE NOTCH. (DO NOT USE THE INDICATOR TO FIND NEUTRAL). 4. LOOSEN THE BOLT (2) FROM THE SWIVEL (4) THAT CLAMPS THE SHIFT ROD (1) TO THE TRANSMISSION EQUALIZER LEVER (3). MAKE SURE THE ROD SLIDES FREELY IN THE SWIVEL. 5. SET TRANS LEVER (3) IN NEUTRAL DETENT. OBTAIN NEUTRAL DETENT BY INDEXING TRANS LEVER ALL THE WAY CLOCKWISE TO "PARK", THEN COUNTER-CLOCKWISE TWO DETENTS TO "NEUTRAL". (ALTERNATE PROCEDURE IS ROTATE TRANS LEVER COUNTER-CLOCKWISE ALL THE WAY TO "L1", THEN ROTATING IT CLOCKWISE FOUR DETENTS.) 6. HOLD THE ROD (1) TIGHTLY IN THE SWIVEL (4) AND TIGHTEN SCREW (2) TO 25 N.M (18 LBS. FT.). DO NOT ALLOW THE ROD TO MOVE IN THE SWIVEL WHILE TIGHTENING. 7. VERIFY PROPER ADJUSTMENT:

***INSERT FIGURE 3 HERE***

PLEASE NOTE THESE NEW PROCEDURES IN THE APPROPRIATE SERVICE MANUAL, SECTION 7A.

WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

LABOR OP DESCRIPTION LABOR TIME K5244 LINKAGE, SHIFT ADJUST USE PUBLISHED LABOR OPERATION TIME

FIGURES: 3

CAPTIONS: FIGURE 1 - TYPICAL S/T LINKAGE FIGURE 2 - TYPICAL M/L LINKAGE FIGURE 3 - TYPICAL C/K LINKAGE

Object Number: 82957 Size: FS

Object Number: 82956 Size: FS

Object Number: 82955 Size: FS

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.