Replace your faulty factory vacuum actuated 4x4 engagement system with a reliable cable operated system. The 4x4 Posi-Lok system eliminates the vacuum actuator and puts the driver back in control. After engaging the transfer case, a one inch pull of the 4x4 Posi-Lok cable connects the right front axle to the intermediate shaft using the shift collar and fork, and 4-wheel drive is engaged! Simply reverse the procedure to disengage 4-wheel drive. 4x4 Posi-Lok also works great with lockers! When the front axle is locked, you can disengage the passenger side in order to make turns without wheel hop.