S15/T15 Jimmy 2WD L4-119 1.9L VIN A 2-BBL (1983)
Throttle Valve Assembly: Technical Service Bulletins
A/T - Harsh and Delayed Upshifts
Number:
84-11
Section:
7A (VIIc)
Date:
Oct., 1983
Subject:
HARSH AND DELAYED UPSHIFTS
Model and Year:
ALL THM 700-R4
TO:
ALL CHEVROLET DEALERS
Beginning with the 1984 production, the THM 700-R4 transmission is being produced with a T.V. exhaust checkball in the control valve assembly. The
purpose of the TV exhaust checkball is to prevent low or minimum line pressure in the event the TV cable should break or become disconnected.
CHECKBALL
This TV exhaust checkball is located beneath the throttle lever and bracket assembly (see illustration - #91). It is normally held off of its seat by the
throttle lever and bracket assembly. If the T.V. cable should break or become disconnected, the T.V. exhaust checkball will seat and cause elevated line
pressure, causing harsh and delayed upshifts.
When servicing any THM 700-R4 transmission for harsh and delayed upshifts, install a line pressure gage to the line pressure tap location to verify
elevated line pressures. If line pressure is elevated, inspect the T.V. cable and the throttle lever and bracket assembly for proper connections. Connect
and/or replace the cable or bracket assembly as required.
The 1982 and 1983 THM 700-R4 transmission sections will show a T.V. exhaust valve in error. The T.V. exhaust checkball went into production in
1984 and was not in previous years.
