A/T - Firm or Harsh 1-2 Shift/Soft or Slipping 1-2 Shift
Number 84-7-31B Date 10/84Subject: I. FIRM OR HARSH 1-2 SHIFT
II. SOFT OR SLIPPING 1-2 SHIFT
1983-1984 200-4R TRANSMISSIONS MODELS BT, BY, BQ, AND OM
MODELS AFFECTED: Grand Prix, Bonneville, Parisienne, Parisienne Wagon
Some 1983 and 1984 THM 200-4R transmissions (Models BT, BY, BQ and OM) may experience a condition relating to the above subject..
Beginning in February 1984, the parts in the service packages listed below went into production to correct these conditions.
Subject I. Firm or Harsh 1-2 Shift
Use the following service package for transmission models BT and BY.
Service Package: 8639912
1 - Control Valve Body Assembly
1 - Intermediate Servo Cushion Spring
1 - 1-2 Accumulator Piston Spring
1 - Pressure Regulator Valve Spring
1 - Control Valve Body Spacer Plate
1 - Instruction Sheet
Service Procedure:
Remove the following parts and replace them with the parts contained in the above service package.
1. Control Valve Body Assembly
2. Intermediate Servo Cushion Spring
3. 1-2 Accumulator Piston Spring
4. Pressure Regulator Valve Spring
5. Control Valve Body Spacer Plate
6. 3-4 Accumulator Piston Spring
FIGURE 1:
FIGURE 2:
NOTE: The 3-4 Accumulator Piston Spring Item #6 above is to be removed and discarded. The 3-4 accumulator piston is to be assembled as shown in Figures 1 and 2.
Subject II. Soft or Slipping 1-2 Shift
Use the following service package for transmission models BQ and BM.
Service Package 8639914 for the BQ Model Transmission
1 - Control Valve Body Assembly 1 - 3-4 Accumulator Spring
Service Package 8639915 for the OM Model Transmission
1 - Control Valve Body Assembly 1 - 3-4 Accumulator Spring
Service Procedure:
Remove the control valve body assembly and the 3-4 accumulator spring from the transmission and replace with the control valve body assembly and the 3-4 accumulator spring provided in the appropriate service package.