FITTING TOPPER TO THE TRUCK
SELECT THE CORRECT TRUCK
Select the correct truck as it is important to the fitting topper to the truck. Also, just as important, the customer’s responsibility to select the right truck for the topper. Indeed, selecting the right combination of topper and truck requires understanding a few guidelines. Firstly, the truck bed mounts to the frame of the truck with mounts that allow for some movement. Also, to prevent damage, allow enough clearance between your truck and topper. If too close, damage may occur 
due to normal racking, twisting and bouncing during driving conditions. Additionally, the cab-over topper model should never be closer than 1 1/2″ to the tallest point of the cab of the truck. This includes cab marker lights or tracking system antennas, if installed.
FITTING TOPPER TO THE TRUCK SPACKING
Importantly, ensure several inches of clearance exist between the truck bed side rails and the topper side wings. Because a tapered bed exists in many truck models. Therefore, the bed depth is different between the front and rear. This discrepancy makes the topper appear tilted (front higher than the rear) along the bed of the truck. If necessary, place a bed mat in the truck bed to raise the topper to gain the minimum clearance requirements.
All trucks include a Federal Certification Label is located on. It is usually located on the driver side door post. Importantly, this label lists the Gross Vehicle Weight Rating (GVWR). Which is the maximum weight at which the vehicle may be operated. Also, it provides a Gross Axle Weight Rating (GAWR) which is the maximum weight allowed for each axle. The GAWR, divided by two, is the maximum axle rating for each end of an axle.
TRUCK TOPPERS WEIGHT FOR YOUR TRUCK
Accordingly, toppers are considered “truck payload”. The glove box in new trucks posts the payload capacity. Or, located on a specification sheet supplied with the truck owner’s manual. Also note, trucks with many options and/or a 4-wheel drive option show less payload capacity. To calculate payload, the truck manufacturers assume all seat positions hold persons weighing 150 pounds each.
One way to determine the actual payload available is to weigh the truck full of fuel and with the number of passengers you will normally be carrying. Then subtract that weight from the GVWR. Truck manufacturers also provide a “center of gravity zone” for topper loading. See your trucks manual to determine the weights to match with your new topper. More information for understanding truck weights.
LOADING AND UNLOADING TOPPER TO FITTING THE TRUCK
When fitting a topper to the truck, it is very important the center of gravity of the topper falls within the zone specified by the truck manufacturer. Please note, the figure below illustrates the location of the topper center of gravity within the center of gravity zone of a typical truck. Further, this center of gravity zone locates from the center of the rear axle to a point about 18″ forward thereof.
CENTER OF GRAVITY
The topper is labeled on both sides with the center of gravity location on the topper. (If no labels are present contact Kuntry Kustom RV to confirm COG) If the center of gravity of a truck topper is allowed to be behind the center of the rear axle, in other words, out of the truck’s center of gravity measurements, the truck may become light on the front end. Consequently, a light front end may cause steering and handling problems, thereby jeopardizing the safety of the occupants while in transit. More information on truck camper COG.
