If you use your pickup truck for heavy hauling and don't need a full-blown commercial vehicle, a Tommy Lift gate lift is a useful accessory for elevating heavy goods in and out of the truck. The installation of a Tommy Lift gate is a bit technical. It requires some mechanical know-how as well as some automotive electrical work to power the gate.
Recruit a partner to help with handling the heavy parts. Use an engine hoist and chain for lifting if you can't find someone to help you. Remove the tailgate from the pickup truck. Disconnect the safety cables on both sides of the truck door. If the door sits in a cradle hinge, position it at its halfway point of descent and lift it up to disconnect it. If it is bolted in, use a socket wrench and pliers to disconnect the door hinges.
Have your partner hold one side of the lift assembly while you carry the other side of the gate so it won’t drop or be awkward to install. If you can't find a partner, use an engine hoist to suspend the lift until it is in place. Install the main door/ramp component of the Tommy Gate to the back of the truck by lining it up with bolt holes in the internal side walls of the end of the truck. Drill the holes with a power drill if they don't already exist. Use metal rods to hold the gate onto the truck until you are ready to insert the bolts -- taper pins work well for this purpose.
Connect the motor/pump assembly that comes with the kit. Lift the engine with both hands carefully as it is heavy and can hurt your foot or body part if dropped. Tighten the two long kit bolts per the kit instructions so that the engine is engaged with the gate mechanism. Bolt the engine assembly to the gate to keep it in place. Use vise grip pliers to keep the lift bracket and the truck wall together until you're done attaching the bolts -- this makes it easier to line up the holes.
Attach the hydraulic hose connections from the gate to the motor. Connect the drive part that pushes the gate up and down, as instructed.
Engage the electrical connections to the vehicle by connecting the red and black wires to the truck wiring for a car battery power source. Use a wire snipper/crimper tool as necessary with wire connectors to splice and attach the wires to each other.
Prime the hydraulic system with new hydraulic fluid. Make sure there is no air left in the tubes by keeping one hose open and draining it until all that comes out is fluid. Have the fluid pour into an old container so it doesn't contaminate the ground. Recycle it later on. Seal the last hose when the air is bled and complete the hydraulic fill by connecting that hose to its junction point right away -- otherwise air will get back in. Using a screwdriver, check all the hoses to make sure their connecting clamps are in place and tight.
Turn the truck on. Turn the Tommy Gate Lift motor on and test the gate. Make sure to run the gate at least five times up and down to make sure everything is working correctly. Rebleed the hydraulic lines and refill them if the motor works fine but there's not enough pressure to operate the lift.
