For 1990-2009 cars

# REVISED DRIVE LINK WEAR SPECIFICATION 125C-440 T4

#### MODELS AFFECTED: 1982-1988 CIMARRONS 1985-1990 DE VILLES AND FLEETWOODS 1986-1990 ELDORADOS AND SEVILLES

This bulletin supersedes Service Bulletin T-90-35 which should be discarded. This bulletin is being revised to change the drive link wear specifications.

The Hydra-Matic 3T40 (THM 125-C) drive link wear specification has been changed from a maximum of 1-1/16" (27mm) to 7/8" (22.2mm) to minimize noise. The THM 440-T4 (4T60) specification remains 1-1/16" (27mm). It is important to inspect the drive link assembly (chain) for possible wear whenever service repair requires disassembly of the transaxle. This is especially important if drive link wear is the suspected cause (i.e., chain whine noise and/or slip due to looseness). The service procedure is listed below:

1. Midway between the sprockets and at right angles to drive link push the slack strand (bottom strand) of the drive link unit down until all slack is removed, and mark with pencil on the bottom side of the drive link. Refer to Figure 1.

2. Push up on the drive link in the same manner and put a second mark on the case making sure that both marks are made from the same point on the drive link.

#### IMPORTANT: If the distance between the two marks exceeds the specification, replace the drive link. Make sure the three machined surf aces indicated in Figure 1 are flush with the machined surface of the case. If not, drive link measurement will be inaccurate.

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.