3-2 COAST DOWN CLUNK (NEW VALVE BODY SPACER PLATE)

Subject: 3-2 COAST DOWN CLUNK (NEW VALVE BODY SPACER PLATE)

Models Affected: 1993 FIREBIRD MODELS WITH 5.7L (LT1) ENGINE AND 4L60 TRANSMISSION

THIS BULLETIN IS BEING REVISED TO CHANGE THE AXLE NUMBER FROM 2.23 TO 3.23 AXLE IN VEHICLE APPLICATION SECTION. THIS BULLETIN CANCELS AND REPLACES BULLETIN 93-7-21 ISSUED 7/93. PLEASE DISCARD BULLETIN 93-7-21.

TRANSMISSION APPLICATIONS: SUBJECT: ------------------------- ------- 1993 HYDRA-MATIC 4L60 3-2 Coast Down Clunk (New Valve Body Spacer Plate)

TRANSMISSION MODELS: VEHICLE APPLICATIONS: ------------------- -------------------- 3FMM F-Cars with 5.7 liter engine and 3.23 axle

CONDITION:

--------- Some vehicles equipped with a 1993 HYDRA-MATIC 4L60 transmission built before February 8, 1993 (Julian Date 039) may exhibit a 3-2 coast down clunk.

CAUSE:

----- A revised 3-2 calibration has been released for the 4L60 transmission.

CORRECTION:

---------- To reduce the 3-2 coast down clunk, install a new valve body spacer plate.

DESCRIPTION PART NUMBER ----------- ----------- valve body spacer plate 8686065

NOTE: 1993 HYDRA-MATIC 4L60 transmissions built on or after February 8, 1993 (Julian Date 039) have been assembled with a new valve body spacer plate.

Parts are currently available from GMSPO.

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.