Harsh 3-2 Shift Maneuver At 17-20 MPH

IV. HARSH 3-2 SHIFT MANEUVER AT 17-20 MPH

1985-1/2 - 1986 Century, Electra/Park Avenue, Riviera, and LeSabre models

A 3-2 shift maneuver is obtained by allowing the vehicle to coastdown to 17-20 mph (with closed or zero throttle) and then stepping into the throttle to obtain a 3-2 shift.

Service Procedure:








At start of production (SOP) 1987, an orifice pipe was added between the 1-2 servo release cover plate and the 3-2 coastdown valve to allow a smoother second gear apply (Figure 6). The four new parts installed as a set will service certain past model transaxles with a harsh 3-2 shift maneuver condition.


Parts are currently available from GMSPO.

Service Manual Reference:

Refer to the HYDRA-MATIC 4T60 (ME9) Automatic Transaxle Unit Repair Table of Contents for appropriate service information.

Service Notes:

If the new pump body assembly has a "one terminal" 3rd clutch switch, remove it and replace with the "two terminal" 3rd clutch switch from the original pump body assembly.





When servicing a transaxle for the above described condition in designated high altitude areas (Figure 8), also install the 3-2 control valve spring package described in Section II of this bulletin.

Also ensure the 3-2 control valve and 1-2 servo control valve move freely in their bores.