4 Wheel Drive Upgrade Actuator for all 6.5 equipped K series P/U trucks, Suburbans and Tahoes using the upgraded 5 wire actuator.

This is usually the reason why your 4 wheel drive front axle won't engauge. Some select vehicles were factory upgraded from the TLA Thermal Linear Actuator, to a Linear Motor actuator. This is the replacement for that actuator motor. Before ordering, check the harness connector on your actuator.

There is a switch located on the transfer case that supplies power to this actuator when in 4x4. Check and replace that switch also. Its p/n ssd-016 also in this category.

If a 92-97, your truck originally came with a ssd-012 or ssd-019 actuator. Please check your actuator and compare to the photos. To use this upgrade actuator, you will need adaptor/harness kit ssd-600600, ssd-6317 or ssd-6319 (depending on year and model) unless your truck has already been upgraded previously.

If you have a 98+ truck, this actuator is an exact replacement.