Can a 4×4 vacuum shift motor be replaced?
Replace your old fading vacuum shift motor with the rugged 4×4 Posi-Lok. The 4×4 Posi-Lok is a driver operated manual cable system that replaces the failure prone vacuum engagement system. When installing a 4×4 Posi-Lok system, we recommend that you also replace the shift fork inside the axle housing.
Where does engine vacum go in Jeep Wrangler YJ?
When the shift occurs, engine vacum is placed on lines running from the transfer case to the axle. This manually controlled shifter ensures instant 4WD engagement and works great with lockers.
How does engine vacuum affect the modulator valve?
When higher amounts of engine vacuum act on the modulator, the transmission begins to shift earlier and softer. As engine loads increase, vacuum diminishes, causing the transmission to shift later and more firmly.
How is the modulator connected to the engine?
The modulator is connected to the engine through a combination of steel tubing and rubber hoses. When higher amounts of engine vacuum act on the modulator, the transmission begins to shift earlier and softer. As engine loads increase, vacuum diminishes, causing the transmission to shift later…
How do you unplug a shift motor on a Jeep Wrangler?
The vacuum lines that run to the top of the shift motor will need to be unplugged. Simply pull them off of the tips that stick out of the motor. Once disconnected, carefully remove the outer bolts of the motor housing. Keep in mind that gear oil will spill out of the housing once it is loosened and removed.
When higher amounts of engine vacuum act on the modulator, the transmission begins to shift earlier and softer. As engine loads increase, vacuum diminishes, causing the transmission to shift later and more firmly.
How does a Jeep Wrangler YJ shift into 4WD?
YJ’s are different from their CJ predecessor, as well as the new ’97-’02 TJ Wranglers and 91 and up XJ’s, by having a two-piece axle shaft on the passenger side. Shifting into 4wd is done through the console shifter sending an impulse to the front motor via the vacuum lines.
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.