Download Free 4×4 Front Axle Engagement Troubleshooting Guide.pdf Use this definitive 4-wheel drive front axle engagement guide to understand, diagnose, and repair those mysterious 4-wheel drive front axle issues. This guide explains how the OEM units function, what causes them to fail, and which corrections are available. 4x4 Posi-Lok is the patented cable activated engagement device designed to replace the failure prone vacuum and electric front axle engagement systems. 4x4 Posi-Lok is not a posi-trac or locker. 4x4 Posi-Lok is simple and easy to install and allows you to engage your front axle from inside the cab. Posi-Lok guarantees that your 4-wheel drive will engage every time because you are in direct control of front axle engagement. A one inch pull of the 4x4 Posi-Lok cable ensures you will have 4-wheel drive when you need it, as long as the transfer case is engaged.

4x4 Posi-Lok [Patent No. 5,605,213] was invented by Dick White in the early 1990’s. Prompted by multiple failures on his own late model Chevy 4-wheel drive, White realized that the TLA (Thermal Linear Actuator) wasn’t engaging the right front wheel even when the transfer case was in 4-LO and the 4-wheel drive dash light was on. After careful study and design, White invented a cable operated actuator to replace the failing TLA. The new system functioned flawlessly, and provided a benefit that the factory design could never provide: 2-wheel drive low range. White went on to develop a Posi-Lok system for the vacuum actuated Chevrolet/GMC T-10/15 Sonoma Pickup, Blazer and Jimmy, Dodge Ram Pickup and Jeep Wrangler YJ, Cherokee XJ and Comanche MJ.

“The ‘throw’ or ‘pull’ of this device is minimal at one-inch or less, and once you get the feel of it, shifting on the fly is easy, as is locking or unlocking the front axle engagement from a stop. This is an aftermarket accessory that makes sense for everybody.”