A tonneau cover is an excellent way to protect the contents of your truck bed and improve your truck’s appearance. However, tonneau covers can develop problems over time that lead to uneven folding.
Uneven folding indicates your tonneau is no longer sitting flush and snug on your truck bed. An uneven tonneau cover can flap around at highway speeds, allowing dust and moisture into your truck bed.
In this comprehensive guide, we will explore the most common reasons tonneau covers fold unevenly and how to prevent the problem. Read on to learn what causes tonneau covers to lose their smooth, even folding and what you can do to fix it.
What is a Tonneau Cover?
Before diving into what causes uneven folding, let’s make sure we all understand what a tonneau cover is.
A tonneau cover sits on top of your truck bed, covering and protecting the entire bed. Tonneau covers come in three main styles:
- Roll-up tonneau covers – These covers use horizontal aluminum slats connected by a vinyl-covered material. You roll the cover up toward the cab to access the bed.
- Retractable tonneau covers – Also known as roll-top covers, retractables use horizontal slats that roll up on a spring-loaded frame. You pull a strap to roll up the cover.
- Hinged tonneau covers – Hinged covers use large vinyl-covered panels that you fold up for access. Most are hard covers made of aluminum or fiberglass.
All three tonneau styles protect your truck bed when closed. Uneven folding causes gaps that allow weather and debris inside. Next, let’s look at why tonneau covers lose their smooth, even fold.
What Causes a Tonneau Cover to Fold Unevenly?
There are several common culprits behind an unevenly folding tonneau cover:
Improper Installation
The number one cause of a tonneau cover folding unevenly is improper installation. Tonneau covers come with detailed instructions that must be followed precisely. If something is off even a little during installation, it can lead to:
- Uneven mounting – If one side or corner is mounted higher than the rest, the cover will sag and flap on the lower side.
- Overtightening – Some tonneaus use tension adjusters. Overtightening them can warp the cover.
- Under tightening – Not making the cover taut enough allows movement and flapping.
- Incorrect rail placement – The side rails must be positioned properly so the cover sits flat.
Taking time to install your tonneau precisely according to the manufacturer’s instructions is crucial. Rushing the job or missing steps can cause lifelong uneven folding.
Worn Parts
Tonneau covers have many moving parts that wear over time. As parts loosen and degrade, the cover loses its ability to fold evenly. Here are key places to inspect for wear:
- Hinges – On hinged covers, worn hinges can lead to sagging and uneven gaps.
- Sliders – Sliders on roll-up covers can crack or warp, causing uneven sliding.
- Bow rods – Damaged or bent rods on a roll-up cover prevent even rolling.
- Seals – Cracked or damaged seals allow wind flap that strains the cover.
Do a thorough inspection of all the tonneau’s hardware every six months. Replace any parts showing wear right away before bigger issues arise.
Improper Use
How you use your tonneau cover also determines if it folds evenly over time. Avoid these improper uses that strain the cover:
- Overloading – Excess weight causes sagging and damage. Never exceed load limits.
- Top access – Climbing on the cover can damage the hardware. Always access from the sides.
- Improper cleaning – Harsh chemicals and scrubbing can degrade the vinyl.
- Neglected maintenance – Lack of lubrication causes unnecessary friction and wear.
Treat your tonneau cover gently, clean it properly, and perform regular maintenance. Following the manufacturer’s care guidelines keeps your cover folding evenly.
Normal Wear and Tear
Even with proper installation, care, and maintenance, tonneau covers gradually wear out over time. The vinyl cover material slowly degrades and the hardware loosens. For roll-up covers, repeated rolling and unrolling also cause mechanical wear.
On average, expect a tonneau cover to last around five years before needing replacement. Higher-end covers may last up to 10 years if properly maintained. If your cover is more than five years old, uneven folding could simply indicate reaching the end of its normal lifespan.
Weathering
Since tonneau covers live outside, sun, wind, rain, snow, and other weather take a toll over the years. The elements gradually degrade the vinyl material, gaskets, and hardware. Prolonged exposure to UV rays from the sun are especially damaging.
Covers in hot sunny climates or that see winter road salt deteriorate faster. Keep your tonneau clean and lubricated to minimize weathering, but expect some unevenness after years in the elements.
Manufacturing Defects
In rare cases, brand new tonneau covers fold unevenly right away due to manufacturing defects. This is most likely with cheaper covers but can happen with any brand. Defects include:
- Misshapen or warped slats
- Vinyl cover miscut
- Bore holes drilled incorrectly
- Faulty hardware
If you notice uneven folding right after installation, contact the manufacturer immediately. Most offer a warranty and will replace a defective cover.
Now that we’ve covered the main causes, let’s look at solutions for fixing an unevenly folding tonneau cover.
How to Fix an Unevenly Folding Tonneau Cover
If your tonneau cover already folds unevenly, don’t panic. In many cases, you can restore smooth operation by fixing the underlying issue. Start with these troubleshooting tips:
Reinstall the Cover
If your cover developed uneven folding gradually, the cause is likely improper initial installation. Try fully removing the cover and rails. Follow the manufacturer’s instructions to reinstall everything from scratch.
Take your time to position the rails perfectly evenly and make sure the cover is taut but not over tightened. Test the folding before permanently screwing everything in place.
Inspect and Replace Worn Parts
Examine every part of the tonneau hardware for damage. Look for:
- Cracked or warped slats
- Torn corners or vinyl
- Loose or degraded seals
- Damaged hinges
- Bent bow rods
Order replacements for any problem parts right away. Use new clips and screws during reinstallation to ensure a tight fit.
Clean and Lubricate Components
A thorough deep clean and fresh lubrication can often restore smooth operation to worn parts.
- Wash vinyl with mild detergent. Avoid harsh chemicals.
- Lubricate hinges, bearings, sliders, rollers, and tension adjusters.
- Check the owner’s manual for recommended lubricants.
Proper ongoing maintenance prevents premature deterioration.
Adjust Tension and Alignment
If there are tension adjustment screws, use them to tighten or loosen the cover in strategic spots to remove sagging and get an even fit. You can also adjust rail alignment by loosening, shifting, then retightening them.
Upgrade Hardware
For older covers with extensive wear, upgrading to newer model replacement parts can provide a longer-lasting fix. New bow rods, bearings, sliders, and tension adjusters restore performance and durability.
Weatherproof Regularly
To minimize weathering, treat the vinyl with protectants and UV inhibitors. Keep the cover clean to prevent debris abrasion. Garage your truck or invest in a tonneau cover protector.
Replace Defective Covers
If your cover had problems right away, don’t waste time trying to fix a defective product. Get a replacement under warranty if possible. For older covers, it may be time to buy a new one.
With some detective work and proper care, you can get your tonneau cover folding evenly again. Next, let’s look at ways to prevent uneven folding in the first place.
How to Prevent Uneven Folding
An ounce of prevention is worth a pound of cure when it comes to tonneau covers. Here are tips to keep your cover folding evenly for years:
Choose Quality
Higher-end tonneau covers made with thick, reinforced vinyl and aluminum or fiberglass panels resist wear and weathering much longer than cheaper covers. Only buy from reputable brands known for quality and durability.
Install Correctly
Refer back to the manufacturer’s instructions with each step during installation. Have a helper to ensure rails are perfectly straight and centered before permanently fixing them in place.
Inspect Regularly
Make it a habit to open your cover and inspect all surfaces and hardware every couple months. Lubricate components and fix small problems before they compound.
Follow Care Guidelines
Clean and treat the vinyl only with approved products. Don’t overload the cover or walk on it. Perform maintenance on schedule. Park in the shade whenever possible.
Use Gentle Cleaning Methods
Only use soft cloths, mild soap, and low-pressure water to clean your cover. Avoid harsh chemicals or scrubbing that could cause premature wear.
Add Protective Accessories
Use tonneau cover protectants and UV inhibitors to minimize weathering. Tonneau cover protectors shield the vinyl from sun and debris.
Repair Damage Quickly
At the first sign of wear, tear, cracking, or malfunction, order replacement parts right away. Never drive with a damaged cover.
Know When to Replace
Most covers need replacement every 5-10 years. Upgrade to new technology to improve convenience and durability.
Get the Most From Your Tonneau Cover
Tonneau covers provide invaluable protection and improved looks for pickup trucks. Follow this guide to keep your cover always folding evenly and smoothly. With proper installation, care, and maintenance, your tonneau will guard your truck bed through all weather for years to come.
