Beginning approximately April 1984, a slot was added to the case cover of the THM 125C transaxle (figure 1). The slot was added the "Drive feed" oil circuit to allow transmission fluid to spray onto the drive link (chain) to provide additional lubrication. The slot is a "V" shaped groove cut into the case cover in the area and direction as shown in figure 1. The slot is intentional and should not be considered as a damaged case cover.
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.