RV Fender Skirt Replacement, Cracking Prevention & Installation Tips
Have you noticed cracks developing around the mounting screws on your RV’s fender skirts? You’re not alone! Cracked fender skirts are a common problem on travel trailers and fifth wheels, including many Grand Design RV models.
At California RV Specialists, we’ve seen this problem repeatedly over the years. In many cases, the issue isn’t simply the quality of the plastic fender skirt. It’s how the skirt is mounted, how the fasteners apply pressure, and whether the mounting surface properly supports the material.
In this episode of In The RV Shop with Dustin, Dustin and Terry are working on a 2020 Grand Design Reflection fifth wheel, replacing damaged fender skirts and explaining why they frequently crack around the screw holes.
More importantly, we demonstrate installation techniques that can help reduce stress on the material and prevent premature cracking.
Why Do RV Fender Skirts Crack?
RV fender skirts are typically made from molded plastic materials designed to provide a finished appearance around the wheel openings.
Although these components are lightweight and flexible, they can become damaged from vibration, temperature changes, road movement, and improper mounting.
One of the most common failures we see is cracking that begins directly at the mounting screw holes.
1. Excessive Pressure Around Mounting Screws
When a mounting screw is tightened against the plastic, it can create concentrated pressure around the fastener hole.
If the screw is overtightened or the plastic is forced against an uneven surface, the material can begin to develop small stress fractures.
Over time, vibration and normal RV movement can cause those cracks to spread.
2. Dimpled Mounting Holes
One of the issues Dustin explains in the video involves the dimple created around the mounting screw holes.
When the fastener pulls the fender skirt inward, the plastic can become distorted around the mounting point.
This distortion creates stress in the surrounding material, especially when the fender skirt isn’t sitting evenly against the RV body.
As the RV travels down the road, repeated movement and vibration can contribute to cracking.
3. Uneven Mounting Surfaces
Another issue involves differences in surface height between the fender skirt and the RV body.
If the skirt doesn’t sit naturally against the mounting surface, tightening the screws can force the plastic into an unnatural position.
Instead of allowing the material to remain relatively relaxed, the installation places continuous tension on the fender skirt.
This can eventually result in cracking around the fasteners.
4. Road Vibration and Body Movement
Travel trailers and fifth wheels experience vibration and movement while traveling.
Even normal road conditions can cause the RV body, frame, and attached components to move slightly.
When a plastic fender skirt is installed under excessive stress, this repeated movement can accelerate material fatigue.
5. Sun Exposure and Aging Plastic
Ultraviolet exposure, heat, cold, and aging can also affect plastic components.
Over time, some materials become less flexible and more susceptible to cracking.
However, replacing an old fender skirt without addressing the original mounting conditions may allow the same problem to happen again.
How We Help Prevent RV Fender Skirts From Cracking
At California RV Specialists, we don’t simply remove the damaged fender skirt and install another one using the same approach.
We pay attention to the mounting points, surface alignment, and the way the fasteners contact the plastic.
Our goal is to reduce unnecessary stress on the replacement component.
Step 1: Remove the Damaged Fender Skirt
We carefully remove the existing fasteners and damaged fender skirt.
During removal, we inspect the mounting locations for cracked plastic, damaged screw holes, distorted mounting surfaces, and other concerns.
Step 2: Inspect the Mounting Surface
Before installing the replacement, we examine how the new fender skirt fits against the RV body.
We look for raised areas, uneven surfaces, and mounting points that could force the plastic into an unnatural position.
Proper alignment is an important part of the installation.
Step 3: Properly Prepare the Mounting Holes
One of the important techniques demonstrated in our video involves modifying the way the mounting holes are prepared.
Properly sized clearance holes and appropriate mounting preparation can help prevent the fasteners from placing excessive pressure on the plastic.
The correct approach depends on the skirt design, fasteners, and mounting surface. The goal is to secure the skirt without distorting it.
Step 4: Install the Replacement Without Excessive Stress
We position the replacement fender skirt carefully, checking alignment before securing it.
Fasteners should be installed using appropriate pressure without overtightening or pulling the plastic into recessed or uneven areas.
Proper support and mounting alignment can make a significant difference in the longevity of the replacement component.
Step 5: Inspect and Seal Where Appropriate
After installation, we inspect the completed repair and address applicable seams or mounting areas using compatible sealants where needed.
Sealant should be selected based on the materials and location, and should not interfere with drainage or required movement.
Watch: Why Your RV Fender Skirts Are Cracking (And How to Fix It!)
Join Dustin and Terry inside California RV Specialists as they replace the damaged fender skirts on a 2020 Grand Design Reflection.
In this video, you’ll learn:
- Why cracks commonly develop around fender skirt screw holes.
- How mounting screw pressure can damage plastic components.
- Why dimpled mounting points and uneven surfaces matter.
- How we prepare mounting holes to reduce stress.
- What we do differently when installing replacement fender skirts.
- How proper installation may help extend the life of these components.
Watch the full video:
Can You Repair a Cracked RV Fender Skirt Instead of Replacing It?
In some situations, minor cracks may be repairable using plastic repair techniques appropriate for the specific material.
However, repairs may not hold if the plastic is brittle, the mounting area is severely damaged, or the original installation problem remains unresolved.
For extensive cracking, missing pieces, or damage around multiple fasteners, replacing the fender skirt is often the more practical option.
Important: Even when replacing the component, it’s worth inspecting and correcting the mounting conditions that contributed to the original failure.
Does This Problem Only Affect Grand Design RVs?
No. Although our video features a 2020 Grand Design Reflection, fender skirt cracking can occur on many brands of travel trailers and fifth wheels.
The same basic concerns can apply to plastic fender skirts and exterior trim components used by different RV manufacturers.
The exact repair method will vary depending on the RV model, skirt material, and installation design.
Recommended RV Sealant & Installation Supplies
Here are several products we use or recommend for appropriate RV exterior sealing applications.
Dicor Cap Sealant – Black
Dicor Cap Sealant – White
Dripless Caulking Gun
Always verify sealant compatibility with the RV exterior material and the specific application before use.
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Need RV Fender Skirt Replacement or Exterior Repairs?
At California RV Specialists, we provide professional RV repair, maintenance, and upgrades for travel trailers, fifth wheels, and motorhomes.
Whether you’re dealing with damaged fender skirts, exterior trim, body sealants, roof maintenance, suspension problems, brakes, or other RV concerns, our team can help evaluate your repair options.
We have been serving RV owners since 2003 and work on many makes and models.
California RV Specialists, LLC
200 S. Cherokee Lane
Lodi, CA 95240
Phone: (209) 263-7040
Website: https://www.calrvspecialists.com
Business Hours: Monday–Friday, 8:00 AM–4:00 PM
All repair services are performed by appointment at our Lodi facility.
Learn More With In The RV Shop With Dustin
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Have you experienced cracked fender skirts on your travel trailer or fifth wheel? Share your RV’s make, model, and year in the video comments. We’d like to hear about your experience!
