How to check a wrangler front axle vacuum?
Check the vacuum at the transfer case switch. Check port to port at the switch with the transfer case shifter in different positions. If the switch is defective or leaking off, you would not have vacuum on a circuit. Make sure the vacuum source line from the engine manifold is in good shape and that the check valves are okay, too!
Why is the vacuum switch on my Jeep Wrangler not working?
Inspect the ball bearing plunger at the bottom of the switch. This gets jammed inside the switch. Try and give it a few bangs to release the jammed ball-bearing inside the switch. If that is unsuccessful, you can purchase a new vacuum switch here. Screw in the new switch and reconnected the vacuum harness to the top of it.
How does a vacuum shift work on a wrangler?
This shift mechanism splits the right side axle shaft power flow when the transfer case is in 2WD mode. Simply put, by splitting (disconnecting) power flow through the right front axle shaft, drag is reduced at the front axle and driveline.
Why is my Jeep Wrangler not engaging in 4WD?
Screw in the new switch and reconnected the vacuum harness to the top of it. Start the Jeep to test the 4WD functionality then take it for a drive on a low-traction dirt road and test between engaging 2H and 4H and back to 2H again.
How does the vacuum work on a wrangler?
The vacuum is to the front axle disconnect mechanism. This shift mechanism splits the right side axle shaft power flow when the transfer case is in 2WD mode. Simply put, by splitting (disconnecting) power flow through the right front axle shaft, drag is reduced at the front axle and driveline.
Where is the vacuum shift motor located on a wrangler?
The right side axle shaft is a two-piece design, split at the vacuum shift motor. So, you do need the front axle disconnect mechanism to work for 2WD and 4WD modes. There’s a shift fork and vacuum motor assembly mounted on the front axle (right side).
What causes Jeep Wrangler 4 wheel drive to not engage?
Jeep 4 Wheel Drive not engaging 1 Failed Actuator. The actuator is a component found mostly on modern four-wheel drives and is designed to electronically engage 4 wheel drive. 2 Vacuum Hose Damage. 3 Vacuum Hoses Unhooked or ripped off. 4 Faulty Vacuum Switch.
How to repair a Jeep Wrangler YJ vacuum schematic?
Fig. 6: Emission control vacuum schematic-1992 with 4.0L engine Access our Jeep Wrangler-YJ 1987-1995 Vacuum Diagrams Repair Guide by creating an account or signing into your AutoZone Rewards account. Once you sign in, follow these instructions to access our Repair Guides. Add your vehicle in Manage My Vehicles.