TORQUE CONVERTER CLUTCH GROWL NOISE-INSTALL NEW MEMCAL PROM

SUBJECT: Growl Noise TCC Release (New Mem-Cal Prom / E-Prom)

TRANSMISSION APPLICATIONS: 1991 & 1992 HYDRA-MATIC 4L80-E/4L80-EHD (MT1)

TRANSAXLE MODELS: 1991 CAP, 1992 MKP

VEHICLE APPLICATIONS: 6.2 Diesel, G-Van

CONDITION:

---------- Some 1992 HYDRA-MATIC 4L80-E/4L80-EHD transmissions may experience a Torque Converter Clutch growl noise.

CAUSE:

------ This is caused by too low of a vehicle speed for Torque Converter Clutch release.

CORRECTION:

----------- A new Mem-Cal Prom was released that raises the Torque Converter Clutch release point.

DATE OF PRODUCTION: (Figure 1) ------------------------------ Starting April 1, 1992 (Julian Date 091) all 1992 MKP HYDRA-MATIC 4L80-E/4L80-EHD models were built with the new Mem-Cal and TCM.

PARTS INFORMATION:

Previous Previous New New Broadcast Code Mem-Cal Broadcast Code Mem-Cal (E-Prom) (E-Prom) -------------- -------- -------------- --------- ATUA 16160302 BBKK 16179337

For vehicles repaired under warranty use:

Labor Time: G-Van 0.5 Hour

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.