There are 3 causes of noise or vibration and they are easy to solve. Please check and fix in the order presented.
- Improperly positioned rail system.
- Rail Cross Piece seal has detached in some spots and is fluttering/vibrating.
- Rail Cross Piece seal is protruding beyond the front bed rail and will vibrate when vehicle speed and/or cross winds are just right.
These issues can be present at the same time. If your panels are moving significantly at speed, it is caused by air movement inside the truck bed. The main cause of this air movement could be because the last panel is not sealing tightly against the tailgate. A good seal is obtained by properly adjusting the distance between the rail and the tailgate. The part of the rail shown below must be 3/16” from the closed tailgate. This distance MUST be the same on the driver and passenger side.
Set the tailgate to rail distance
The second and third causes could be a vibrating Rail Cross Piece (RCP) seal. This is not a common issue, but it does happen from time-to-time. If you suspect this, consider the following remedy.
First check to ensure that the seal is attached securely and completely along the entire length of the RCP. If the adhesive has failed in some spots, the seal will "flutter" at that point and this will cause noise. You will either need to apply weatherstrip adhesive, or order a new seal. Someone will need to examine the seal using a flashlight when lying inside the truck with the cover extended.
IF it is attached completely AND it protrudes beyond the front bed rail, consider tucking the seal underneath the rail cross piece as shown in figure 3. This will keep this seal from fluttering in the wind, which may be causing the issue. You’ll need to loosen the rail mounting bolts to do this. Do not tuck this seal under the rail if it is NOT protruding beyond the bed rail. If you find the seal gets untucked after driving then reach out so support@peragon.com for additional assistance.