A roll-up tonneau cover is a popular truck bed cover that provides protection and improves your truck’s appearance. However, over time, the vinyl cover may start to sag or the corners may droop.
This can look unsightly and allow rain or debris to get into your truck bed. Luckily, it’s usually an easy fix to get your tonneau cover looking taut again!
What Causes Tonneau Cover Corners To Droop?
There are a few potential causes for drooping tonneau cover corners:
- Loss of tension – The vinyl cover needs to maintain tension to stay stretched tightly across the bed. Over time, the tensioning system can loosen, causing the fabric to sag.
- Improper installation – If the cover wasn’t installed correctly or the tension wasn’t properly set, the corners may not have been tight enough from the beginning.
- Damage – Small rips, tears, or holes along the edges of the cover can lead to a loss of tension and cause drooping.
- Temperature changes – In extreme cold or heat, the vinyl material may expand or contract, altering the tension and allowing corners to drop.
- Normal wear – Over many years of use, the fabric can stretch out, causing a gradual loss of tension.
How Can I Adjust The Tension?
Most roll-up tonneau covers have a tension adjustment system that can be used to tighten the cover. Here are the general steps:
Step 1: Release The Cover
Start by unlatching the cover and rolling it towards the cab of your truck. This will expose the underside of the cover where the tension adjuster is located.
Step 2: Locate The Tension Adjuster
There are a few types of tensioning mechanisms:
- Tension knobs – Turnbuckle knobs on either side can be twisted to increase or decrease tension.
- Tension blocks – Sliding blocks on the crossbows can be moved to tighten or loosen the fabric.
- Strap adjusters – Some covers have straps with buckles that can be shortened or lengthened.
Refer to your owner’s manual if you’re unsure what your cover has.
Step 3. Adjust The Tension
- For knobs, turn them clockwise in small increments to tighten.
- For blocks, slide them away from the cab to increase tension.
- For straps, shorten them by pulling excess strap through the buckle.
Go slowly and check the results frequently to avoid over-tightening.
Step 4. Roll Down The Cover
Once tension seems sufficient, carefully roll the cover back down and latch it. Walk around the perimeter and ensure the corners are now lifted and taut. Make further small adjustments if needed.
How Can I Keep My Tonneau Cover Corners From Drooping Again?
With the tension reset, here are some tips to maintain optimal tension over time:
Check The Tension Regularly
Get in the habit of inspecting the cover every few months. Roll it up and check that the fabric is still tight. Make minor tension adjustments proactively rather than waiting for corners to droop again.
Use Truck Bed Bows
Vinyl tonneau covers should come with bed bows – horizontal bars that snap into place perpendicular underneath the cover. Using these bows will help support the cover to avoid future corner sagging.
Park In The Shade
If possible, park your truck in a garage or shaded area. This protects the vinyl from extreme temperature fluctuations that can cause contraction and stretching.
Fix Any Damage
Promptly patch any small rips, tears, or holes by the corners or perimeter of the cover using vinyl repair kits. This prevents tension loss through compromised fabric.
Keep The Cover Clean
Regularly remove debris with a brush and clean the vinyl with mild soap and water. This prevents degradation and wear from dirt, mud, and UV exposure.
What If Adjusting The Tension Doesn’t Fix Drooping?
If you’ve gone through the steps to increase tension and the cover still won’t stay taut, there could be a larger underlying problem:
What if the tension adjustment knobs or blocks are broken?
ANSWER: If your tension mechanism is damaged or no longer functioning, the entire system may need replacement. You’ll want to contact the manufacturer to see if just the tension assembly or the whole cover needs to be replaced.
What if there are large rips or holes near the edges?
ANSWER: Larger damage to the vinyl can prevent proper tensioning. The best fix is to patch or sew the holes closed before readjusting tension. If the cover is too far gone, replacement may be required.
What if the fabric is badly warped or stretched out?
ANSWER: Over many years, the vinyl can lose elasticity and the fabric itself may become loose and stretched out. At this point, the cover has reached the end of its lifespan and likely needs complete replacement.
What if I suspect the cover wasn’t installed correctly from the start?
ANSWER: It’s possible the cover was never tensioned properly upon installation. Removing and re-installing from scratch can allow you to set the tension correctly. Follow the manufacturer’s instructions precisely.
Getting a new replacement cover is the remedy if the current vinyl cover is too damaged or worn out to tighten back up through tension adjustment.
When Should I Replace My Truck Bed Tonneau Cover?
While you can prolong the life of a tonneau cover with proper cleaning and maintenance, they unfortunately don’t last forever. Here are some signs that indicate it’s time to replace your cover:
- The vinyl fabric is badly cracked, brittle, or ripped in multiple spots
- The cover has become excessively loose and saggy despite tension adjustments
- The corners won’t stay up no matter how much you tighten the tension knobs
- There are gaps or holes along the perimeter seam stitching
- Water is leaking through the fabric even when latched closed
- The cover fabric has become faded and dull from years in the sun
- It’s become challenging to roll up and down without catching or sticking
Replacing an old, worn-out vinyl tonneau cover with a new one can restore protection for your truck bed while also improving your truck’s appearance. Investing in a high quality, durable cover will give you better performance and longer lifespan before needing another replacement.
Drooping, sagging tonneau cover corners are usually just a minor issue that can be fixed with some simple tension adjustments. By releasing the cover, locating the tensioner knobs/blocks/straps, and incrementally tightening, you can pull the fabric back taut across your truck bed again.
Regular maintenance and prompt repairs will keep your cover in good shape. But if age or damage has taken its toll, replacing the vinyl cover is the ultimate solution for eliminating those unsightly drooping corners for good.
With the right care, your tonneau cover will keep your truck bed protected and stylish for years to come!