A/T - Slips in Reverse/No Reverse

90buick01

Bulletin 90-7125-3

Date Nov., '89

Ref. No. 90-035-7125

Corp. Ref. No. 977149

SUBJECT: SLIPS IN REVERSE AND/OR NO REVERSE (LO-REVERSE PISTON SMP RING LOCATION INFORMATION)

MODELS AFFECTED: 1989-90 3T40 TYPE TRANSMISSIONS (THM 125C)


BULLETIN COVERS

Incorrectly installed Lo-Reverse Piston Snap Rings (657) that may cause a slip in reverse and/or no reverse condition.

Figure 1:

SERVICE PROCEDURE (Refer to Figure 1)

Whenever installing the Lo-Reverse Clutch Piston Snap Ring (657), the step on the outside diameter of the snap ring must be positioned toward the Lo-Reverse Clutch retainer (656). The retainer must rest inside the snap ring to allow proper piston travel.

If the snap ring is installed backwards with the step facing the splines on the hub, the retainer may limit travel of the piston and may result in a durability concern.