A Step-by-Step Guide to Install a Hard Tonneau Cover The Easy Way

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Installing a tonneau cover on your truck can be taxing and tedious, often because you have to find the right cover to match your vehicle. Sometimes this isn’t possible; your vehicle may be unable to take any tonneau cover. However, you can modify your truck to allow those that don’t fit naturally to come as close as possible to matching correctly. Let’s take a look at how to install a hard tonneau cover.


Certain vehicles come with attachments such as railings, which can get in the way of a tonneau cover. Browsing and talking to dealers will help you find the right cover for you or one that could potentially fit with a little help.

There are many other things to consider when choosing a cover, such as what you’re going to be using it for, how often you’ll need it, and whether or not it’ll just be in the way. If you cannot find a cover to fit your vehicle, you may need to look at modifying your truck for a cover.

Installing the Rails

The following are the necessary steps for installing the side rails which come with purchasing a tonneau cover.

  1. Lower the tailgate, as this can be in the way and cause issues when it comes to getting the cover flush.
  2. Tonneau covers ideally come with two side rails to attach to the bed rails. These must be loosely fitted on, but not fully tightened as adjustments must still be made. Should your model not come with side rails, it may have side rails attached to the cover itself, which will make attaching and detaching easier.
  3. Near the cab, clamp the side rails down with the toothed clamps provided. On the side rail, you should find grooves that indicate where to clamp down on the side rails. Once located, tighten until it is held loosely in place; not too tight that adjustment would be difficult.
  4. Sometimes there will be gaps between the side rail and bed rail. Here, you can use shims to close the gaps by inserting them evenly between the bed and side rails. More significant gaps may require shim brackets instead, which still work off the same principle.
  5. With the gaps now taken care of, you can add more clamps. Evenly space them out along the sides down towards the back of the truck without tightening them beyond being able to be adjusted.

If you haven’t attached the second side rail yet, repeat steps 2 through 5 for that side.

With both rails attached, adjust them using the clamps to be parallel with one another. It would be best if you aimed to have them horizontally flat with the bed rails. The reason the tailgate is open is to prevent it from misaligning the adjustments, as the tailgate will not necessarily align with the rails.

With all adjustments made and the rails parallel, lock them in place by tightening all the clamps, ensuring they do not misalign.

Installing the Cover

Now that you have aligned the railings and locked them in place, you can install the cover itself to the bed of the truck.

Weatherproofing the seals is essential, so rubber seals have been provided. Starting from the cab side, stick the rubber seals along the interior of the side rails down to the hind of the bed.

Some designs offer additional features with additional components. Some might include a security strap for storage, tension adjusters, or hinged covers to allow the bed to be more easily accessible. These should be installed as required by design, i.e., threading the straps through their necessary holes and installing the tension adjusters to the side rails.

Align the cover with the side rails. It should slide in perfectly if the adjustments are correct. If not, push down slightly as it may be held back by friction. Otherwise, you will have to readjust the side railings so that the cover can fit.

Now you carefully unhinge and unfold the cover so that it covers the whole bed. Make sure that both ends are flush with the tailgate and the cab.

Bolts are provided for you to secure the now placed cover to the side rails. Before you start securing the cover, double-check the alignment and fitting of the cover to the bed. Once you are confident it fits perfectly, bolt in the cover.

Tighten the clamps one last time to make sure the railings do not come loose. Should they come off, you will damage your truck as well as the cover.


Unfortunately, not every cover will be perfect for every vehicle. Some minor changes will have to happen to fit the tonneau cover to the bed of the truck, which mostly involves cutting and removing pieces of the railing. Bed liners often get in the way of clamps, but a simple fix is to cut a notch into the bed liner for some extra space.

Rail caps can also get in the way of installation. Removing them as necessary will cause little harm, as they are, more often than not, in the way of the weatherproofing seals, an essential item for installing a cover.

Final Thoughts

Fortunately, modifications are small and easy to do. The same can be said for installing covers. So now that you’re confident in fixing a cover to your truck, make sure you follow the steps to the letter so that you have a safe and secure bed.

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