CONTROL VALVE AND SPACER PLATE CHANGE E,K, SERIES

VEHICLES AFFECTED: 1984 Eldorados and Sevilles (Gas Engine Equipped)

A transmission calibration change took place which affected the control valve assembly, spacer plate, and associated gaskets on 1984 Eldorados and Sevilles equipped with HT4100 engines and AJ or AE model THM 325-4L transmission. This change took place in production beginning at transmission serial numbers 84 AJ 84686 and 84 AE 4838 (refer to Figure 1).

The use of incorrect service replacement parts may result in abnormal shift conditions.

When servicing transmissions built prior to the above listed serial number breakpoints, refer to the early design calibration parts information in this bulletin. For transmissions built on or after the breakpoints, refer to the late design calibration parts information.

EARLY DESIGN CALIBRATION PARTS SERVICE INFORMATION

REFER TO PART NAME IDENTIFICATION PART NUMBER FIGURE --------- -------------- ----------- ------

Control Valve Assembly 'AJ1' (ink print)* 8639640 2 Spacer Plate 'AB' (stamp) 8635655 3 Gasket Kit, fits only None 8635919** 3 early design or (superceded by) Gasket Kit, fits V-Notch 8635976** 4 either design

LATE DESIGN CALIBRATION SERVICE PARTS INFORMATION

REFER TO PART NAME IDENTIFICATION PART NUMBER FIGURE ---------- --------------- ----------- ------- Control Valve Assy. 'AJ2' (ink print)* 8635974 2 Service Kit Spacer Plate 'AJ' (with V-Notch) 8635661 4 Gasket - Kit V-Notch 8635976** 4 3-4 Accumulator Piston Pink and Green 8639858 Spring 3-4 Accumulator Piston ---- 274612 5 Snap Ring Instruction Sheet 8635975 -

*Ink print markings on control valve assemblies denote model type (letters) and calibration level (numbers). Level numbering begins with '1' each new model year.

**Contains case side and control valve side spacer plate gaskets and accumulator housing gasket. Individual gaskets are not available separately.

***The late design control valve is not available separately, the service kit also contains spacer, gaskets, 3-4 accumulator spring, late design snap ring and instruction sheet.

NOTICE: Transmission overhaul kits (part numbers 8635906 and 8635916) packaged prior to mid-September, 1984 (date listed on package) contain spacer plate guskets which can only be used with the early calibration control valve assembly and spacer plate. Overhaul kits packaged after mid-September do not contain spacer plate gaskets.

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.