1983 C20 3/4 Ton Pickup 2WD V8-350 57L Automatic Transmission Valve Body TSB 89637A
Valve Body: All Technical Service Bulletins
A/T - New Control Valve Assembly Elimination of TCC Bore
Number:
89-63-7A
Section:
7A
Date:
JAN., 1989
Subject:
NEW CONTROL VALVE ASSEMBLY ELIMINATION OF TCC BORE
Model and Year:
1982-89 CAPRICE, CAMARO CORVETTE
WITH 700-R4 TRANSMISSION 1982-89 C1, C2, K1, K2, R1, V1, S2, T1, G1, 2, 3, M WITH 700-R4 TRANSMISSION
Figure 1
TO:
ALL CHEVROLET DEALERS
This bulletin covers service information for new THM 700-R4/HYDRA-MATIC 4L60 control valve assemblies. The new control valve assembly will
no longer have the TCC bore, and now contains a "notch" in the channeling allowing 2nd Clutch oil into the TCC circuit (refer to Figure 1). The TCC
bore, in the past, has housed either the converter clutch throttle valve and sleeve or the converter clutch bore plug. The converter clutch throttle valve
was used on models that had non-ECM controlled TCC apply. The converter clutch bore plug was used on models that had ECM controlled TCC apply.
Starting with 1989 production, all THM 700-R4/HYDRA-MATIC 4L60 models are ECM controlled TCC apply. Since there are no current production
models using the converter clutch throttle valve, the TCC bore is not needed and has been eliminated.
