S10/T10 P/U 4WD V6-173 2.8L (1986)
Transfer Case Actuator: Customer Interest
Drive Axle (Front) - Will Not Disengage
Number:
91-476-4C
Section:
4C
Date:
JAN. 1992
Corporate Bulletin No.: 167402
ASE No.: A3
Subject:
FRONT AXLE WILL NOT DISENGAGE
Model and Year:
1983-1991 T TRUCKS
Owners of some 1983-1991 T vehicles may comment about inappropriate front axle disengagement. This condition may be due to a corroded transfer
case vacuum actuator switch. To correct this condition a revised switch (P/N 15664811), constructed of noncorrosive stainless steel, should be installed.
SERVICE PROCEDURE:
The vacuum switch is located on the left upper side of the transfer case (Figure 1).
1.
Raise the vehicle and support with suitable safety stands.
2.
Remove the vacuum lines from the switch.
3.
Remove the corroded switch from the transfer case.
4.
Install a revised switch (P/N 15664811), coat the threads with thread sealant.
5.
Connect the vacuum lines.
6.
Lower the vehicle.
7.
Check for oil leaks at the threads and vacuum leaks around the vacuum lines.
