OEM Systems

The Weak Link

Vacuum Actuator

• The OE unit is vacuum controlled. This vacuum system is prone to failure due to frozen diaphragm, loss of vacuum, hard or cracked vacuum hoses, or complete loss of vacuum lines.
• The OE unit can cause excessive wear on the differential and/or right axle and shift fork breakage due to incomplete engagement or disengagement.
  

Chevy

1983–2001 S-10, S-15 Pickup, Blazer, Jimmy

Dodge

1985–1993 1500-3500 Pickup, Ramcharger, & Trailduster

1994–2001 Ram 1500 Pickup

1994–2002 Ram 2500, 3500 Pickup

Jeep

1987–1995 Wrangler YJ

1984–1991 Cherokee XJ

1986–1991 Comanche MJ

Ford

1997–2003 F-150 Pickup

Thermal Actuator

• The colder the temperature, the longer it will take to engage.
• If the front differential becomes submerged, the TLA temperature will cool and the 4-wheel drive will disengage.
• The TLA unit can cause excessive wear on internal components in the differential and may cause other electrical problems.
  

Chevy/GMC

1988-98 Chevy/GMC K1500, K2500, K3500

1992-98 Suburban, Tahoe, Yukon

How 4x4 Posi-Lok Works

The Weak Link is Eliminated

Vacuum Actuator

The failure prone vacuum actuator is replaced with the cable operated 4x4 Posi-Lok system. The vacuum actuator is removed from the front axle tube. Engaging the transfer case and pulling the Posi-Lok handle will slide the shift fork and collar to connect the freewheeling right axle to the driven left axle. Both front wheels are now engaged and pulling the vehicle.

Thermal Linear Actuator

The failure prone thermal linear actuator is replaced with the cable operated 4x4 Posi-Lok system. The cable’s handle is conveniently routed under the dash. Placing the vehicle’s transfer case in 4-wheel drive and pulling the Posi-Lok cable handle slides the shift fork and collar to connect the freewheeling right axle to the driven left axle. Both front wheels are now engaged and pulling the vehicle.