TRANSMISSION NOISE WHEN COLD NEW SYNCHRO RING P/N

A NEW MANUAL TRANSMISSION SYNCHRONIZER RING, P/N 94238647 HAS BEEN RELEASED TO SERVICE SERIES 5 THRU 10 LUV TRUCKS WITH A HIGH PITCH WHINE IN 3RD AND 4TH GEAR WHEN COLD. TYPICALLY THIS WHINE WILL OCCUR ONLY UNDER 40F AND DISAPPEARS AFTER INITIAL WARM UP. THIS NEW BLOCKER RING INCORPORATES REVISED CONTOURS TO PREVENT OIL DRAIN DURING SHUT DOWN PERIODS. WHEN SERVICING A UNIT FOR THIS CONDITION, IT WILL BE NECESSARY TO REPLACE BOTH BLOCKER RINGS IN THE 1-2 SYNCHRONIZER ASSEMBLY. IT IS NOT NECESSARY TO REPLACE THE SYNCHRONIZER ASSEMBLY.

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.