UPDATE- HM4L60/700-R4 A/T DIAGNOSIS

TRANSMISSION MODELS: VEHICLE APPLICATIONS:

4L60 70OR-4 B,D,F,V,Y AND C/K, G,L,M,R/V S/T TRUCKS

Bulletin Covers:

New Product Information for 1990 HYDRA-MATIC 4L60 transmissions. This information has been updated since publication of the 1990 Service Manual and should be noted accordingly. Be certain to familiarize yourself with these updates to properly diagnose the 1990 HYDRA-MATIC 4L60 transmission.

DATE OF PRODUCTION CHANGE:

Beginning with Start of Production 1990, HYDRA-MATIC 4L60 transmissions were built with the product changes explained in this bulletin.

SERVICE MANUAL REFERENCE: (Figures 1 and 2) ------------------------ Figures 1 and 2 update the charts located in the Transmission Diagnosis section of the 1990 Service Manuals.

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.