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How to Install the 5th Airborne Sidewinder PinBox by Reese/Cequent Towing

Originally Published in Trailer Life Magazine

Towing a 37-foot fifth-wheel with a long-wheelbase dually can challenge even the most seasoned RVers when it comes to maneuvering in tight places. Our prior, shorter fifth-wheel was fitted with a 5th Airborne Sidewinder pin box, which made negotiating city streets, tight fuel stations and technical backing into tight campsites a pleasure. The Sidewinder (Reese/Cequent Towing Products) was designed to eliminate the need for a sliding hitch when towing with a short-bed truck. Missing the svelte handling characteristics of the old fifth-wheel setup, but not the improved livability afforded by the new 37-footer, we reasoned that the 5th Airborne Sidewinder might have a positive effect on our current fifth-wheel and long-bed truck combo. After discussing this application with the Reese tech people, we installed the Sidewinder and realized better-than-expected results.

The installation of the 5th Airborne Sidewinder would have been easier and faster with the use of a forklift for assistance. The ideal situation is to assemble both parts of the pin box and the turret assembly on a forklift, then raise into place and torque the bolts to the recommended specification of 150 ft-lb. Budget approximately one hour for installation.

Due to the fact this installation was completed in a campground, the task was a bit more challenging and required the generous assistance of our able-bodied neighbor. Following the guide in the manual for matching the spacers to the turret assembly, we installed the roll pins so that the holes in the spacers would line up to the frame bracket of our factory Fabex PB-500 pin bracket.

You will need to know which pin box you have in order to properly match the hole pattern. If you are unsure of the pin box model simply hold up the spacer plate to the frame wing brackets to determine the correct hole pattern to follow in the directions. This will allow the arm to clear the wings during pivoting.

With the spacer attached to the turret assembly, the turret is raised into place and the six bolts are torqued to 150 ft-lb. Be sure that the notches on the spacers face downward and that the turret assembly protrudes below the frame wings.

The pin box arm comes in two pieces with multiple holes for height adjustments. Take several measurements from the bottom of the turret to the bottom edge of the trailer to get a rough idea of which hole pattern to utilize. A minimum of 1-inch clearance with the full weight of the trailer (landing jacks retracted) on the hitch is required. Once this clearance has been determined, the two parts are assembled and torqued to the required 200 ft-lb.

The next step is to install the wear plate onto the pivot arm with the chamfer edge facing downward. With the pivot bushing in place, apply a thin coating of white lithium grease to the pivot bushing and wear plate. The pin box assembly is then locked into the fifth-wheel hitch. Using a block of wood and a bottle- or floor-jack, the pin box assembly is roughly leveled so that the pivot tube is vertical.

Once in place, the truck is backed up so the pivot tube is aligned under the turret assembly. Slowly lower the trailer so the turret assembly slides down over the pivot tube — you may need a block of wood and a heavy hammer to prevent sticking or binding during this process. You may have to raise or lower the bottle jack to keep the pivot tube in proper alignment with the turret.

When the bottom of the turret comes into contact with the wear plate, the upper wear disc should be installed and the top cap with the supplied bolts tightened temporarily to 25 ft-lb. It’s critical that the upper wear disc shows no visible gaps prior to tightening the upper cap bolts.

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Raise the trailer so that the Sidewinder lifts off the fifth-wheel hitch and remove the bottle jack support. Torque the cap bolts to 45 ft-lb, being careful to follow the tightening pattern in the instructions. Over tightening will cause the arm to bind.

The wedge on the Sidewinder prevents the kingpin from pivoting in the hitch. This allows the Sidewinder to pivot at the turret 22 inches back from the kingpin. The universal wedge is removed from its storage position after pulling the two bolts and lock washers. Utilizing the same two bolts that were just removed, the wedge is installed in the lock-out position and bolts are finger tightened.

All Sidewinders can be used as a standard pin box for conventional towing by implementing two lock-out bolts that prevent rotation of the turret and allow use of the pin box without the wedge. Never operate a Sidewinder without either the wedge or the lock-out bolts. Operating without a wedge with the lock-out bolts removed can cause extreme damage to both the truck and trailer.

The type of hitch in your truck will determine the orientation of the universal wedge when mounted. Reese/Cequent offers custom wedges designed for specific fifth-wheel hitches. Inquire with your dealer at the time of purchase to determine if a special wedge will be needed for installation.

At this point, air must be added to the 5th Airborne Sidewinder’s airbag before the first hook up. Pin weights vary from trailer to trailer, so you will need to add an estimated amount of air. A good place to start is at 80 psi. Once air has been added, the trailer can be hitched to the truck. It’s critical that the truck and trailer are in a straight line so that the wedge fits squarely into place.

After the kingpin is locked into place, hammer in the universal wedge so that it’s snug against the hitch. Both bolts may not be accessible while the unit is hitched. Tighten the most accessible bolt to 95 ft-lb, then disconnect the trailer and tighten both bolts to 150 ft-lb. The wedge should never need these adjustments again unless the hitch is changed. Using the same white lithium grease, follow the instructions and lubricate the pertinent points on your particular fifth-wheel hitch model.

Once connected again, pull the trailer forward several feet and complete a few start and stop sequences — each time gently applying the brakes. With the truck and trailer on level ground, place the transmission in park so that the air bag pressure can be fine-tuned. Air can then be added or removed until the bottom plate of the pin box is as level as possible with the ground.

Prior to installing the 5th Airborne Sidewinder, we conducted a series of tests where we measured the exact turning radius using our standard pin box so we could establish an accurate baseline for comparison. With the truck and trailer in a straight line and starting at the center of the rear wheel on the driver’s side, we marked a line 30 feet straight back. Every 5 feet we made a vertical line outward to determine the distance before the trailer’s rear tire would begin to turn.

Before backing up, the steering wheel was cranked all the way to simulate maneuvering into a narrow camp spot. It’s always been a challenge to navigate in and around tight areas, but this was the first time we actually measured the distance before the trailer started to turn. For this test, the rear tire did not begin to turn until we moved 15 feet, producing a turning radius that would have taken us into the next campsite if this had been a real life situation.

The same test was then conducted with the 5th Airborne Sidewinder and it only took 6 feet before the trailer started turning. Clearly, the Sidewinder decreases the turning radius substantially, allowing the user much quicker turning capabilities. Not only is the turning radius considerably shorter with the Sidewinder, it also allowed jackknifing of the trailer into a campsite that would not be possible before installing the new equipment. The Sidewinder on our setup effectively changes the front wheel cut from 46 to 52 degrees.

Another notable feature of the Sidewinder is its ability to track closely behind the truck around sharp curves and narrow corners. This improvement in maneuverability restores confidence when making tight turns in campgrounds or on narrow city roads.

Essentially the fifth-wheel now tracks more like a conventional trailer. The Sidewinder can be used to tow with a step-side truck without risking contact damage to the bed of the truck.

The particular Sidewinder we tested has the 5th Airborne air-ride feature that’s designed to reduce longitudinal shock (chucking motion that comes from trailer weight and not pin weight) by 60 percent and vertical shock by 44 percent. The integration of an air-ride suspension greatly reduces jarring to the inside of the truck, improving ride quality and passenger comfort.

When tested over uneven railroad tracks and speed bumps, the 5th Airborne soaked up the trailer movement rather than succumbing to the truck’s suspension in an attempt to reduce vertical shock. Overall, the 5th Airborne Sidewinder proved to be a very valuable add-on when comparing comfort and handling against using a conventional pin box.

An actual demonstration of the 5th Airborne Sidewinder can be viewed on the Internet via YouTube; simply search for Cequent Towing Sidewinder. The 5th Airborne Sidewinder has a $1,973 MSRP; without the air-ride feature, the price drops to $1,400. All Sidewinders from Reese come with a limited lifetime warranty supported by more than 300,000 test cycles performed to validate durability.

Cequent Performance Products
888-521-0510, www.ReeseProducts.com

Fifth-WheelTrailer How-To

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