TORQUE CONVERTER CLUTCH SHUDDER(NEW CONVERTER ASSY.). GMC Truck GMC Suburban

SUBJECT: TORQUE CONVERTER CLUTCH SHUDDER (NEW CONVERTER ASSEMBLY)

VEHICLES AFFECTED: 1991-93 C/K, R/V AND P TRUCKS, G VAN W/4L80-E/4L80-EHD TRANS

This Bulletin is related to Bulletin GMCL 93-7A-131.

CONDITION:

--------- Some HYDRA-MATIC 4L80-E/4L80-EHD Transmissions may have a Torque Converter Clutch (TCC) shudder concern during apply and/or release.

CAUSE:

----- Torque Converter Clutch (TCC) friction material characteristics do not allow optional Torque Converter Clutch (TCC) apply or release for some vehicles.

CORRECTION:

---------- New Converter Assembly with new friction material.

Starting January 11, 1993 (Julian Date 011) all 1993 HYDRA-MATIC 4L80-E/4L80-EHD models will have the new Converter Assembly.

SERVICE PARTS INFORMATION:

Models Part Engine Name 1993 1992 1991 ---- ------ ---- ---- ---- ---- 8690904 4.3L Conv.Asm. ABP,ACP,ADP, ABP,ACP,AFP, ABP,ACP,ADP AFP,AHP AHP,AJP

8689961 5.7L Conv.Asm. BUP,BYP,BZP, BSP,BUP,BYP, MAP,MJP,MLP, BZP,MAP,MJP MXP,BSP 8690903 6.2L Conv.Asm. BMP,BAP,BJP, BAP,BJP,BMP, BAP,BBP,BJP, JDP,BNP,MPP BNP,MBP,MKP, BMP,BNP,CAP, MBP,MCP MPP CBP,CKP,CRP

8689959 6.5L Turbo Conv. LAP,LFP,LLP LAP,LFP,LLP Asm.

8689960 7.4L Conv.Asm. DCP,DLP,DNP, DCP,DLP,DNP, DCP,DDP,DLP, DPP,DRP,DSP DPP,DRP,HTP, DNP,DPP,DRP, MHP,TVP,TXP, TSP,TWP,MHP DSP TWP

For vehicles repaired under warranty use:

Labor Code: K7020

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.