SERVICING THE TCC VALVE TRAIN THM 200-4R,325-4L/CONT. VALVE

VEHICLES AFFECTED: 1982 Deville, Brougham, Eldorado and Seville

Some early production 1982 Cadillacs equipped with gasoline engines and THM 200-4R or 325-4L transmissions were built with a Torque Converter Clutch (TCC) valve train installed in the control valve assembly of the transmission. This first design control valve assembly (refer to Figure 1) contains a bushing as well as converter clutch throttle and shift valves and a calibration spring.

Beginning late in 1982 production, the TCC valve train was eliminated from the control valve assembly. For an interim period, the second design control valve assembly (refer to Figure 2) contained a hollow bushing to direct TCC signal oil flow. Service stock control valve assemblies no longer utilize the bushing or valve bore; casting changes have been incorporated that eliminate the need for the bushing.

Refer to the following service and parts information when servicing a 1982 THM 200-R4 or 325-4L transmission. It is essential that the proper gasekts and spacer plate be used to assure proper trransmission operation. ON THM 200-R4 applications, incorrect parts will result in reduced fuel economy, and a hard diagnostic code 39 on HT4100 equipped vehicles. On THM 325-4L applications, incorrect parts can result in poor shift quality.

This bulletin provides parts information for servicing first and second design control valve assemblies.

I. THM 200-4R (Deville and Brougham Series Vehicles) Service Information

First design control valve assemblies for the HT4100 and 4.1L V-6 applications are no longer available through GM Parts. If a first design control valve assembly requires replacement, it will be necessary to install a complete control valve assembly service package.

First and second design spacer plates are available for service when control valve replacement is not required.

The second design gasket package will service both first and second design components (refer to Figures 1, 4 and 5). All GM Parts stock of first design gaskets has been superseded by the second design gaskets.

1982 THM 200-R4, CONTROL VALVE ASSEMBLY SERVICE PARTS INFORMATION

First Second Design Design Control Valve Trans Gasket Spacer Spacer Assembly Service Engine Code Package Plate* Plate** Package ** ------ ---- ------- ------ ------- ----------- 4.1L V-6 BY 8634969 8634839 8657026 8634977 HT4100 AA & AP 8634969 9634792 8657010 8634981

* First design spacer plate, not to be used on second design control valve assembly.

** Second design spacer plate, not to be used on first design control valve assembly.

*** Contains second design control valve assembly, spacer plate and gaskets.

II. THM 325-4L (Eldorado and Seville)

Service Information

A. On 4.1L V-6 applications, the complete service package and gasket package must be used when replacing a first design control valve assembly. The service package includes a second design control valve assembly, spacer plate, and a calibration update kit to improve shift quality. The service package DOES NOT include gaskets.

Do not use the first design spacer plate (identified by the letter "U" stamp) with the second design control valve assembly. The second design spacer can be used in both applications.

The gasket package will service first and second design components.

B. On HT4100 applications, the second design control valve assembly is compatible with first design components.

1982 THM 325-4L, CONTROL VALVE ASSEMBLY SERVICE PARTS INFORMATION

Control Trans Valve Gasket Spacer Service Engine Code Assembly Package Plate Package ------- ---- -------- ------- ----- ------- 4.1L V-6 AM N/A 8635982 8635648 8635938* HT4100 AJ 8635955 8635982 8635640 N/A

* Contains second design control valve assembly, spacer plate, and calibration update kit (gaskets not included).

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.