LOW POWER/LACK OF PERFORMANCE INSTALL TRANS. TORQUE CONV.. GMC Truck GMC Suburban

SUBJECT: LOW POWER/LACK OF PERFORMANCE (INSTALL TRANSMISSION TORQUE CONVERTER AND MEMCAL)

VEHICLES AFFECTED: 1991-92 C/K/R/V TRUCKS (OVER 8500# GVW)

CONDITION:

--------- Some owners of 1991-92 C/K and R/V trucks with the H.D. 5.7L engine (VIN K) and 4L80E (RPO MT1) transmission may comment of low power and/or lack of performance. These low-power comments are mostly on heavy throttle maneuvers such as towing, highway passing, and on uphill grades.

CAUSE:

----- The transmission torque converter, engine and transmission calibration (MEMCAL) were not optimum in matching the engine torque curve.

CORRECTION:

---------- This service fix is for all 1991 and 1992 models built before the following VIN breakpoints:

Pontiac East: Chev = E159784 GMC = E523373 Oshawa: Chev = 1173368 GMC = 1525884

To correct trucks, install transmission torque converter P/N 08685994 and Memcal per chart below:

New Memcal New Broadcast Code New Memcal I.D. Type Axle Prom Kit Memcal Label Scan Tool ---- ---- ---------- ------------------ --------------- C,R (2-Wheel All 16173069 BAAX 3001 Drive)

K,V (4-Wheel All 16173073 BAAY 3011 Drive)

Notice: After installation of the above Memcal, your Tech 1 will have to use a 1992 cartridge to obtain correct engine and transmission readings.

Part are availability:

Warranty Information:

Labour Operation: K7020 - Transmission Torque Converter Labour Time: C/R 3.1 Hrs., K/V 4.9 Hrs.

Labour Operation: Memcal Labour Time: .6 Hr.

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.