Transfer Case Actuator: Testing and Inspection

Fig. 1 Selec-Trac Diagnosis, Model 229 Transfer Case (Part 1 of 2):

Fig. 1 Selec-Trac Diagnosis, Model 229 Transfer Case (Part 2 of 2):

MODEL 229 TRANSFER CASE

1. Disconnect vacuum harness from transfer case shift motor and connect suitable vacuum pump to shift motor front port.
2. Apply 15 inches vacuum to shift motor and rotate rear propeller shaft to fully engage transfer case in 4 wheel drive mode.
3. If shift motor does not retain vacuum for at least 30 seconds, replace motor.
4. Disconnect vacuum pump from front port of shift motor and connect to rear port, plug front axle connecting port and apply 15 inches vacuum to motor.
5. Place automatic transmission in Park or manual transmission in 1st gear.
6. If shift motor does not maintain vacuum for at least 30 seconds, replace motor.
7. Remove cap from shift motor axle connecting port and check for vacuum at port. If there is no vacuum, rotate rear propeller shaft as necessary to ensure total transfer case engagement. The transfer case must be fully engaged before shift motor stem will extend fully and open axle interconnecting port.
8. If vacuum is now present at shift motor axle connecting port.
9. If vacuum is still not present, slide boot away from shift motor stem and measure distance stem has extended. Stem should extend 5/8 inch as measured from edge of shift motor housing to E-ring on stem.
10. If shift motor stem does not extend specified distance.
11. If shift motor stem extends specified distance but there is still no vacuum at axle connecting port, replace motor.