Projects & Repairs --> Mechanical --> Tailgate --> 2004 Jeep Wrangler

By Jim Wilk, Licensed Auto Body Technician

Start:

Some SUV's and vans have doors with hinges that are located on the outside of the vehicle, fully exposed to the weather. The Jeep Wrangler tailgate also has exposed hinges.

The trouble with exposed hinges is that they get wet and dirty and the lubrication dries up, and eventually the door becomes difficult to open and close. Proper maintenance for these hinges requires lubricating them twice a year or more.

With these stuck tailgate hinges, I figured there were four possible courses of action I could follow, each more time-consuming than the previous. So I started with the easiest option, ready to try more serious fixes if necessary.

Option One - Penetrating Oil:

This 2004 Jeep Wrangler has exposed hinges on the tailgate. The owner Karen had to use both hands and some body weight to swing this tailgate opened and closed. The hinge pins are encased, so I started by spraying penetrating oil into the opening at the top of the enclosed pin.

I used Rubber-Seal brand of penetrating oil. The aerosol with spray straw works the best. The green arrow shows the best point to access the encased pin.  I started by spraying the oil liberally into the upper ends of each hinge pin. I also sprayed the pin at the bottom. Notice the dirty-white stuff behind the hinge pin? This is overspray from white lithium grease that was not applied carefully enough to get into the hinge. These types of hinges are not easy to lubricate with white lithium grease

After lubricating the hinge pins, I swung the tailgate back and forth to work the oil into the encased pins. I repeated this process at least five times and realized it wasn't working. Then I decided to upgrade my attack to Option Two.

Option Two - Penetrating Oil With Heat:

After applying penetrating oil, the hinge pins were still stiff. So I used a electric heat gun to warm up the metal. I found that I can use an electric heat gun to heat the encased pins carefully and not cause damage to the paint. A torch would definitely ruin the paint... and it might catch the penetrating oil on fire. I kept applying penetrating oil while heating the area.

Heat will cause the metal to expand, and this makes the hinge absorb the oil. I sprayed both sides of the hinge.

Then I swung the tailgate again to work the oil in. After swinging the tailgate a few times, I noticed that it was getting easier to move. After repeating the heating and lubricating process at least twenty times, the tailgate finally started working freely.

In total I spent about an hour and a half getting this hinge to turn freely. This job requires some patience. I'm guessing that it just takes some time for the lubricant to work its way into the tiny spaces between the hinge pin and the tailgate arm.

Karen was able to open and close her tailgate with one hand. Luckily, I didn't have to use Options Three and Four.

Option Three: I would drill a one-eighth inch hole on the back side of the pin encasement near the top, until I hit the pin.  Then I would spray the penetrating oil into the hole.

Option Four: Replace the hinge or pins.

While this doesn't help this Jeep's problem, I'll note that General Motors sells a replacement hinge pin with a grease fitting at the bottom of the pin. If you can get the old pins out they can be replaced with the grease-able kind. Maybe the people at Jeep will smarten up and design something similar for the Wrangler.

This repair was done at R-Tech Auto Body in Traverse City, Michigan.