THM 125C TRANSMISSION UPDATE MULTIPLE SUBJECTS

I. New Design Band Anchor Plug

All THM 125C transmissions are being built with a new design band anchor plug. The new design plug has a tab which holds the part in place. (Refer to Figure 1. )

Transmissions built with the past design band anchor plug required a staking operation to hold the part in place. (Refer to Figure 2.) This staking operation is not required with the new design plug as it is held in place by the reverse oil pipe. (Refer to Figure 3.)

To remove or replace the new design band anchor plug, the reverse oil pipe must be removed.

For service, use the new design plug part number 8637640.

II. Pump Cover to Case Bolt

THM 125C transmissions may contain a substitute pump cover to case bolt. Refer to Figure 4 for bolt location.

The standard pump cover to case bolt is an M8 x 1.25 x 105 bolt, part number 8637266. The substitute bolt is an M8 x 1.25 x 110 bolt, part number 11501048, used with two (2) standard steel washers 1.5mm thick.

If the substitute pump cover to case bolt and washers are removed from any transmission, be certain to use the two (2) washers during assembly. Failure to use the two (2) standard steel washers on the M8 x 1.25 x 110 bolt may result in interference between the converter and the pump cover to case bolt.

After reassembling a THM 125C transmission containing the substitute pump cover to case bolt and washers, install the torque converter and check for interference between the converter and the pump cover to case bolts.

When installing any pump cover to case bolt, be certain to use thread sealer on the bolt threads and torque to 20 N.m (15 ft. lbs.).

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.