NO REVERSE AFTER OVERHAUL OR REVERSE SERVO 'R AND R'

TRANSMISSION APPLICATIONS: SUBJECT:

W/4T60-E NO REVERSE AFTER OVERHAUL OR REVERSE SERVO "R AND R" (NEW PROCEDURE - INSTALLING REVERSE SERVO)

TRANSMISSION MODELS: VEHICLE APPLICATIONS:

1991 C,E,K CAR W/4T60-E

Bulletin Covers:

A vehicle equipped with a HYDRA-MATIC 4T60-E may have no reverse gear after an overhaul or reverse servo repair or replacement. This is because the HYDRA-MATIC 4T60-E has only one large anchor bracket for the reverse band (compared to two for the 4T60). Now, the reverse band is apt to shift off location when the reverse servo band apply pin is removed (the reverse servo band apply pin helps hold the band in the proper location when properly installed). A step must be added to the reverse servo replacement to ensure that the reverse band apply pin and the reverse band assembly are properly assembled. Please add this information to your 1991 Service Manual 4T60-E Unit Repair and On-Vehicle sections.

FOR THE UNIT REPAIR SECTION:

IMPORTANT: ----------

o Turn transaxle case so the channel plate side is up before installing reverse servo assembly.

FOR ON-CAR SECTIONS OF SERVICING THE REVERSO SERVO FOR ANY REASON:

IMPORTANT: ----------

o Before installing the reverso servo:

Check that the band is in the proper location by putting a long Phillips head screwdriver, down the band apply pin hole - push down on the screwdriver, and it must spring back up. If not, the band is mislocated and must be re- located towards the engine with a screwdriver (carefully, so the band apply pin bore in the case does not get damaged). Re-check for proper location of the band.

o If this procedure is not followed, the transaxle will have partial or no reverse gear due to the band apply pin missing the band.

Install reverse servo.

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.