How to Install a Tonneau Cover

wikiHow is a “wiki,” similar to Wikipedia, which means that many of our articles are co-written by multiple authors. To create this article, 10 people, some anonymous, worked to edit and improve it over time.

This article has been viewed 135,376 times.

Tonneau covers come in several types and many specific models. These universal instructions will often be enough, but an unusual model or troubleshooting issue may require contacting the manufacturer. Soft covers are much easier to install than hard covers, and can usually be installed by a non-expert in about an hour. Hard covers are heavy and difficult to install, so ask a friend or two for help.

Get Car Support Solve Any Problem

Hi there! Do you have a question about how to diagnose or fix a problem with your car? I’ve read the manual so you don’t have to. Select your make, model, and year, then ask away!

Try Asking:

We’re sorry we don’t support the car you are looking for. Please enter its make, model, and year below so that we can add support for it.

Send Request

Thank you! We’ll review your request and add support for this product as soon as possible. In the meantime, you can ask more questions about the products we currently support.

Ask New Question Part 1 of 2:

Installing the Cover Rails

If a bed liner gets in the way during installation, just cut a notch where you need to fit a clamp or other cover part.
If the bed liner wraps over the rails and your tonneau cover lies between rails (instead of above them), the two parts might not both fit on your truck.
Most bed rail caps won't affect installation, but diamond plate bed rail caps will prevent some covers from fitting, or from forming a weather-tight seal.

Open the tailgate. A closed tailgate can interfere with installation. Advertisement

If your cover does not come with rails, the cover itself should have clamps that swing down from the underside once the cover is in place. [1] X Research source These covers are less stable and not weatherproof, but easy to remove and reinstall.
If you have a retractable tonneau cover, which comes in a canister, you may need to position this before you place the rails. Put the canister on the edge of the bed rails, next to the cab. Center this perfectly before you attach the rails to the canister. [2] X Research source

Clamp the side rail in place next to the cab. Your installation kit should come with several toothed clamps. Take one of these and fit it onto the underside of the side rail, near the cab. Line up the teeth of the clamp with the grooves, then tighten by hand. Tighten a few times with a wrench or socket wrench, just enough to feel it pressing against the bed rail. [3] X Research source

If there's a large gap (more than about ⅜ inches / 10mm), you might need shim brackets instead. Unclamp the rail, slide the shim brackets onto the end, space them out evenly, and reclamp the rail. [4] X Research source Your kit may not come with shim brackets, or may have shim brackets that attach with a slightly different design.

Some soft tonneau cover instructions recommend skipping this step until the end, so you can make final adjustments more easily. Don't try this for a hard cover, which needs a firm

Repeat with the second rail. Install the second rail the same way.

If there is a gap between your bed rails and the cab, the side rails should not extend into this gap.
The rails will not necessarily be level with the closed tailgate.

Tighten all clamps fully. Once you are certain the rails are properly align, finish tightening the front clamp of each rail with a wrench. Repeat with the other clamps, moving toward the rear of the truck.

Advertisement Part 2 of 2:

Installing the Cover

Some tonneaus come with additional seals for the sides or tailgate, and/or larger corner plugs to weatherproof the rear corners.

Storage straps, fed through holes in the cover.
Tension adjuster screws, for hand tightening of the cover. These usually attach to the side rails, and may come pre-installed.
Hinged covers and some hard folded covers include a rod to prop the cover open. This should snap or screw into place somewhere on one of the side rails, with the other end resting on a small cradle.

If you cannot center the cover, place it back on the ground and readjust the rails.
Hinged hard covers (one solid piece without folds) are extremely heavy. They cannot be installed safely by a single person. Use a forklift or several helpers. [7] X Research source

Look for a small hand-tightened screw on the rail to adjust cover tension. It should lie taut across your bed, completely covering it.

Some covers have clamps or levers on the underside, which lower to brace the cover against the bed side.

Tighten all clamps. Check all clamps on the cover rails and tighten them securely. Check all other attachment points to make sure the cover is firmly in place and cannot shift or come loose.

Install final components. Some tonneau covers come with drainage tubes to divert rain, bump stops to protect your cab from dings when a hard cover is opened, or various other optional components. If you have any parts you cannot identify in your installation kit, contact the manufacturer or a mechanic.

Community Q&A

I'm having a problem with getting the snap on the tarp stretched enough to fasten it. What should I do?

Community Answer

Soak it in a bath of water for 24 hours to soften it and make it much easier to stretch, then put it on and allow it to dry out. You may have to repeat this each year.

Thanks! We're glad this was helpful.
Thank you for your feedback.
If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even $1 helps us in our mission. Support wikiHow

Are the cover rails supposed to fit the length of the bed, or be short? Community Answer

The rails should be very close to the full length of the truck bed. There may be and inch or two less at either end for the edges of the cover, depending on model; but if there is a foot or more gap, then you probably have a short bed cover on a standard- or long-sized truck bed.