C 2500 3/4 Ton Pickup 2WD L6-250 4.1L VIN D 2-bbl (1984)
Valve Body: All Technical Service Bulletins
A/T - Partial Tie Up In reverse
Number:
84-68
Section:
7A (VIIc)
Date:
Feb., 1984
Subject:
PARTIAL FORWARD CLUTCH AND/OR BAND APPLY IN REVERSE GEAR ON THM 700-R4
Model and Year: 1983-84 ALL MODELS PASSENGER CARS AND TRUCKS
TO:
ALL CHEVROLET DEALERS
Some 1983 and 1984 THM 700-R4 transmissions may experience a partial tie up in reverse. This may be caused by a sticking 4-3
sequence valve which could cause a partial band apply or a sticking 2-3 shift valve which could cause a partial 3-4 clutch apply.
When servicing for this condition, refer to the following procedure.
SERVICE PROCEDURE
1.
Remove the control valve body assembly from the transmission.
2.
Disassemble the control valve body assembly and wash all parts with solvent.
FIGURE 1 - Valve/Valve Train
3.. Visually inspect the 4-3 sequence valve and valve train and the 2-3 shift valve and valve train for nicks, burrs, chips and damage
(Figure 1).
4.
If valves or bushings are damaged, replace the control valve body assembly.
5.
If valves and bushings are OK, reassemble the control valve body assembly and install back into the transmission.
