Make your own Tonneau Cover
1 sheet of ¾” plywood
2 8ft 2x4s
2 T-hinges or other style, up to you
2 locking mechanisms of your choice
8 6mmx50mm hex bolts
8 1 ½” machine screws
8 1” or longer wood screws OR 8 2 ½” or longer machine screws
16 ¼” fender washers
8 ¼” locking washers
Ebony wood stain
Satin black exterior paint
Begin by taking measurements of your bed, length, width, etc. Mine was 55 ¼” wide by 51” long, however, due to the plastic cap around the top, yours may have shrunk or expanded more than mine, and therefore you should not just use my measurements. Measure the distance from ½” from the front of the bed to the center of the first screw hole. You will need to remove the plastic caps over these holes with a knife or pull them off with a set of pliers. Then measure the distance between the fist two, then to the next set and the distance between these two holes, and finally the distance from the last hole to ½” before the end of the bed. Measure the distance from the top of the bed to the center of each hole. The bed is not level the whole way across, so you numbers may be different from the front and rear of the bed. Once you have made these measurements, calculate the distance from the bottom of the plywood to the hole by subtracting ¾” from the last measurement you got. This is where you will drill your holes in your 2x4s, which should extend from ½” from the rear of the bed to ½” from the front of the bed. This will allow for some play when you drill your holes and they aren't exactly right, like mine weren't.
Next, head to your local Home Depot or other hardware store and pick out a good piece of ¾” plywood. Make sure it has a good face on it as this will reduce the amount of work you have to do later. Bring your measurements with you and go ahead and have them cut it there, if they have a cutting center. Pick up your 2x4s and have them cut as well. Use the measurements from earlier and you should end with two pieces that are about 42” long and one that is the width of your bed. Also pick up the other hardware listed if you don't already have it.
Start with the 2x4's. Drill holes at the locations you measured earlier. The holes should be located a distance equal to the distance from the top of the plastic to the center of the hole minus ¾” . When you drill the hole, give it about ¾” diameter so you can make adjustments and make the tonneau as close to flush as possible. Then, you will need to countersink these holes to at least 1” down using a drill press or other means.
Bolt these on using the 6mmx50mm hex bolts, fender washers, and locking washers. These will bolt into the factory holes so you do not need to worry about drilling new holes.
Use the 2x4 that is cut to the widh of the bed and notch out the end, like pictured so that it will fit onto the supports you made. Push it firmly against the bed, and screw into place. This will be the mounting bracket for your hinges, as well as fill the gap left by the plywood as the bed is just longer than a sheet of plywood.
Now comes the fun part; lay the sheet of plywood on the supports, and push it against the 2x4 at the front of the bed. Lie underneath the plywood and trace the bed onto it. This is how the snug fit is achieved. After you've done both sides, remove the cover and cut out along the lines with your jigsaw. You will find that the bed is not square and that it begins to taper in about ½ way down. That's normal...I guess. After you've cut out the pattern, test fit it back onto the truck. It will not fit perfectly, but you will see where you need to do the most sanding. Sand the edges using a belt sander until you achieve a perfect fit.
Once you've achieved a fit your satisfied with, rout everything. I used ¼” and 1/8” round bits, and it looks just like the edges of the plastic caps around the bed and tailgate. It really gives it a factory look. Reinstall everything and make sure that it fits the way you like it. Install the hinges by attaching them to the 2x4 at the front of the bed and onto the tonneau cover. I bolted mine down using nuts with plastic thread so that they are difficult to remove, especially if you're only working from one side. It's a small security measure. Be sure to put washers in between the wood and the bolts to help distribute the pressure and not break your hard day's work.
Now you're ready to install you latches that will keep you tonneau locked down and secure. These were $3 a piece at Home Depot and if I need to, I can add a padlock for extra security. Pick a spot between the two mounting holes on your 2x4s and screw in the first piece, the locking mechanism. Then, screw on the second piece, the piece that the locking mechanism attaches too.
Now you're ready to paint. I chose to stain mine black first so that if and when it chips, the chip will be dark and it won't stand out as much. So, sand it, stain it, sand it, seal it, sand it, seal it, sand it, paint it, sand it, paint it, paint it. The more coats of paint you add and the more sanding you do, the less you will see the wood. I chose to leave mine a little rough so it will be an easy repair when it gets nicks. Anyways, you're done! Enjoy your new tonneau cover and enjoy the $400+ you saved by doing it yourself.
Note: I will add to this later when my gas struts arrive. I will show how to install them into this particular setup so that you don't have to always hold the tonneau open with your bare hands.