A/T - 4L60 Shift Lever Squeak Noise

91chevy25

GMC NUMBER: 91-7A-145

GROUP: 7A Automatic Transmission

DATE: September, 1991

CORPORATE NUMBER: 167103


SUBJECT: SQUEAK NOISE FROM SHIFT LEVER

MODELS: 1991 S/T TRUCKS WITH 4L60 AUTOMATIC TRANSMISSION


Some customers may comment about a "squeak", "buzz", or "tizzle" noise when driving a 1991 S/T truck with the 4L60 automatic transmission. A possible cause of the noise has been found at the interface of the transmission shift lever and the transmission control lever.

One source of the noise may be a loose fitting of the transmission control lever to the transmission shift lever. This can generate a vibration induced noise. The addition of a wave washer (as described below in the service procedure) may eliminate this condition. The wave washer (P/N 4722812) will prevent the slight perpendicular movement of the shift lever against the control lever that can cause the noise.

T TRUCKS ONLY (4WD) A second source of the noise is a possible ground-out of the shift lever with the end of the slot in the control lever. This condition can be corrected by the addition of washer (P/N 14074908) to the end of the shift lever that is secured to the frame. At the same time the wave washer is installed, adding washer 14074908 will center the shift lever in the slot in the control lever, preventing the ground-out condition. To install washer 14074908 simply remove the retaining pin on the end of the shift lever that is secured to the frame, place the washer over the lever end, and replace the retaining pin (this is given as an optional step in the service procedure).


VEHICLES INVOLVED:
Trucks built after the following VIN breakpoints have had the new washer installed in production.

Pontiac GMC Truck 1GTCS19RXM0526141
West Chevrolet 1GCCT14Z6M0189004
Moraine GMC Truck 1GNDT13Z6M2507024
Oldsmobile 1GHDT13Z2M2704746
Chevrolet 1GNDT13Z8M2270913
Shreveport GMC Truck 1GKCT18Z1M8537954
Chevrolet 1GCCS19ZXM8245619

FIGURE 1:

SERVICE PROCEDURE: (Figure 1)

1. Apply the parking brake.

2. Disconnect the negative battery cable.

3. Remove retaining pins (10) from each end of the transmission control lever.

Figure 2:

4. Separate the transmission control lever from the transmission shift lever and insert 1-2 wave washers 4722812 (Figure 2) onto the control lever

Figure 3:

NOTE: For T trucks, 1-2 washers 14074908 (Figure 3) should be installed to the opposite end of the shift lever at this time (if necessary).

5. Reinstall transmission control lever into transmission shift lever and install NEW retaining pins.

6. Adjust shift linkage.

7. Reconnect negative battery cable.


SERVICE PARTS INFORMATION:
Parts are currently available from GMSPO.
NOTE: Equivalent wave washer for P/N 4722812 may be obtained locally if the following dimensions are met (Figure 2):

Inside diameter (A) - 0.6 inch +/-
0.005 inch

(15.24 mm +/-
0.127 mm)

Outside diameter (B) - 0.87 inch (22
mm)

Thickness of Wave (C) - 0.017 inch
(0.43 mm)

Peak to Peak Wave Distance (D) - 0.09 inch
(2.286 mm)

Washer must be of a hardened variety.
*NOTE: Equivalent washer for P/N 14074908 may be obtained locally if the dimensions shown in Figure 3 are met.

WARRANTY INFORMATION:
For vehicles repaired under warranty, use:
Labor Operation: K4133

Labor Time: 0.2 hrs.