Antenna/Light Bar OTC

I wasn’t originally going to post this, but the end intermediate result turned out so well it was deemed worthwhile. In setting up the forward mount for the roof rack I planned to pick up, I found out just how easy (and inexpensive) it is on a Discovery to add mounting space for antennas, lights, or whatever else you may want to add up on the roof. To make the bar, you’ll need:

  • 1/4-inch x 3″ x 48″ aluminum flat bar is more than enough for antennas, consider 3/8 or 1/2-inch thick if you are going to add lights (or tweak as necessary for your needs)
  • four 8mm-1.25 bolts with matching flat washers (double-check this if you have a pre-2004 Discovery)
  • tape measure, a marker, a 4mm allen wrench, a drill with a 9mm (or 5/16ths) metal bit, a chop saw or even a hacksaw (aluminum is easy to cut), medium file (for rounding edges), fine-grit sandpaper
  • mineral spirits, bedliner and appropriate brushes (I’ve had good luck with Rustoleum, Duplicolor came out awful)

Home Depot carries the bolts and washers, Metals Depot has great prices on the aluminum.

There are two threaded holes near the rear of each factory roof bar on a Discovery, these are intended for the OEM cross-bar accessory for which Land Rover charges ~$300. These holes are weight-bearing and designed to handle things like canoes, roof racks, and other cargo. They also make for quick-and-easy attachment points for home-built accessories. With the 4mm allen wrench, remove the two protective caps currently occupying these holes. Then grab your aluminum bar and start measuring. I suggest adding a curve to the aluminum bar as this will add strength and rigidity, and provide additional clearance for your antenna/light mounts.

The pictures are pretty self-explanatory. Measure twice and drill the holes in your aluminum bar, including the holes you’ll need for your accessories. Once that is done, test fit the bar with your lowest-hanging accessory and bolt it down so you can make sure nothing touches. At 48-inches, the aluminum flat bar will be within a couple inches of where it should be so you’ll only need to trim a little off the end. Measure and mark for the amount you wish to trim, then take the bar down and trim it. Double-check the fit, then use your file to round the corners and the leading edge of the bar (for aerodynamics). Sand it down all over with the fine-grit sandpaper, then rinse the bar well with mineral spirits and allow it to dry. Follow the instructions that came with your bedliner, and give it an extra day of dry time before attaching the bar. When the bar is completely dry and hardened, attach it and your accessories to the roof. Once everything is in place you can use a little extra bedliner to cover up the shiny bolts.

A Note on Wiring

There is only one clean way to run wires down off the roof, and that is to drill a hole. Despite the horror stories regarding such things, if done right there is no reason for this to cause any leaks or rattles. Where you place the hole is personal preference, but the location of the new antenna/light bar does happen to be right above a spot in the headliner that has ample room for wiring and a factory-provided access panel to get at the roof’s underside. This panel can be found by sitting in the rear seats and looking up—it serves double-duty as a dome light. Pop the lens off of the light, then carefully pry the light housing out of the surrounding plastic. With the assembly out you are looking up at the bottom of the roof metal, right where the new roof bar is located. With a little careful planning and some fish tape you can finish up wiring your new accessories without even dropping the headliner.