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What Causes A Gap Between The Tailgate And Tonneau Cover?

A frustrating issue many truck owners face is a gap between the tailgate and tonneau cover. This gap allows dust, debris and water to get into the truck bed, defeating the purpose of having a tonneau cover. So what causes this vexing gap, and how can you fix it? This comprehensive guide has the answers.

What Is A Tonneau Cover?

First, let’s review what exactly a tonneau cover is. A tonneau cover sits over the truck bed, protecting cargo from weather and theft. Tonneau covers come in [hard folding](What Causes A Gap Between The Tailgate And Tonneau Cover?), soft roll-up, and retractable styles. They are secured to the bed rails with clamps or snaps. When closed, a tonneau cover should seal tightly to the tailgate to keep out the elements.

Why Does A Gap Matter?

A gap between the tailgate and tonneau allows water, debris, and even thieves’ hands to enter the bed. This defeats the purpose of the cover. A tight seal is necessary for optimal tonneau function. Even small gaps let in surprising amounts of weather.

What Causes The Gap?

There are a few common culprits behind tailgate-tonneau gaps:

Misaligned Tailgate

If the tailgate sits crooked or twists out of alignment, it can prevent a flush fit with the tonneau. Even slightly misaligned, it will cause frustrating gaps.

Loose/Worn Seals

The rubber or vinyl seals along the tonneau edges serve to block gaps. But over time, seals can stretch, shrink, or detach, causing loss of that tight seal against the tailgate.

Vibrations

Simply driving causes vibrations that can loosen tonneau covers and tailgates. The constant bumps and shakes allow gaps to form. Retractable covers are especially vulnerable.

Improper Adjustment

Some tonneaus have tension cables or adjustable latches. If these are too loose or too tight, it can throw off alignment and cause tailgate gaps.

Damage

Cracks, dents, warped panels, or broken hardware prevent the tailgate and tonneau from sitting flush, creating openings.

How To Fix The Gap

Depending on the cause, there are a few ways to remedy a tailgate-tonneau gap:

Realign The Tailgate

If adjustment is needed, loosen the tailgate chains or cables and realign the tailgate. You want it sitting squarely against the tonneau.

Replace Seals

Over time, seals compress or deteriorate. Replacing worn seals with fresh ones can often eliminate gaps.

Add A Tailgate Seal

For stubborn gaps, adding a supplemental tailgate seal can help bridge the space between the tailgate and tonneau cover.

Adjust Latches/Cables

For adjustable tonneaus, tighten or loosen components to achieve proper tonneau-to-tailgate alignment.

Repair Damage

Fixing dents, cracks, warped panels or broken hardware may be necessary to restore a flush, gap-free fit.

Professional installation, frequent inspection and proper tonneau care reduce the chances of troublesome tailgate gaps occurring. But when they inevitably crop up, these fixes get your tonneau sealed against the elements once again.

Frequently Asked Questions About Tailgate Gaps

Still have questions about why gaps happen and how to solve them? Here are answers to some commonly asked questions:

Do All Tonneau Covers Get Tailgate Gaps?

Most tonneaus will develop small gaps over time as parts settle and wear. But some are more prone than others. Soft, roll-up covers are most susceptible thanks to their flexible nature. Retractable covers also frequently gap due to their complex sliding mechanisms. Hard covers resist gaps better with their rigid panels. But even they can develop openings if parts become knocked out of alignment.

What’s The Best Way To Prevent Gaps?

Frequent tonneau inspection and adjustment helps catch gaps when they first start. Parking carefully away from carts and traffic also prevents damage that causes gaps. Proper care – cleaning the tonneau and lubricating parts – will maximize longevity. And choosing a premium tonneau brand known for good seals and durable construction helps minimize gaps.

Will Fixing The Gaps Void My Tonneau Warranty?

It depends on the repair. Simple realignment of the tailgate or latch adjustment should not affect the warranty. But altering or replacing seals could void the warranty, depending on the manufacturer. Always check your owner’s manual or contact the company before permanently modifying the tonneau.

How Do I Know If I Need A New Tailgate Seal?

You’ll know it’s time for a new tailgate seal if adjusting the tonneau and tailgate still leaves gaps, or if the existing seal is visibly damaged – cracked, loose, or torn. Seals lose effectiveness over years of compression. Fresh seals make a world of difference in preventing gaps.

Can I Drive With The Tailgate And Tonneau Gapped?

It’s not recommended. The opening allows road debris and moisture into the bed which can damage cargo or rust the truck. Aerodynamic drag is also increased, hurting gas mileage. For optimal tonneau function, keep the tailgate-tonneau junction sealed tight.

Key Takeaways On Tailgate-Tonneau Gaps

  • A gap defeats the purpose of a protective tonneau cover by allowing weather/debris into the bed.
  • Misaligned tailgates, worn seals, vibration, and damage are common gap causes.
  • Solutions include realigning parts, adjusting latches, replacing seals, and fixing damage.
  • Routine inspection and proper care reduce the chances of gaps occurring.
  • Sealing the tailgate-tonneau junction maintains cargo protection and aerodynamics.

Gaps between tonneau covers and tailgates are an annoying issue, but also a fixable one. With some strategic adjustment and part replacement, you can keep your tonneau cover sealed against the tailgate, rain, snow and wind. Your cargo will stay dry and protected from the elements where it belongs – inside the truck bed!

Meghan Drummond
Meghan Drummond

Meghan has owned trucks for over 20 years and installed her first tonneau cover back in 2005. She has tested over 50 different tonneau cover models hands-on. Meghan has a journalism degree from the University of Florida and previously worked as an auto writer.

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