How To Reinforce A Cargo Trailer Ramp Door

Reinforcing Ramp Doors on Cargo Trailers

Ramp door installation requires the right specifications and measurements, there are two important factors to consider when thinking of installing a ramp door on an enclosed cargo trailer. The specifications, as in dimension and weight for trailers vary from manufacturer to manufacturer, verification of measurements is vital before buying a cargo trailer. For an enclosed trailer, overhead torsion spring systems are important, it could be a single torsion spring or double torsion spring. Double torsion springs have one cable on each side of the door and single torsion springs have one cable only. Some double torsion trailers have specifications of 96 inches wide or 81 inches wide, # ERS160D96 for the 96 inches and # ERS120D81 for the 81 inches. The single torsion trailers specification can either be 66 inches wide or 96 inches wide, #ERS80S66 for 66 inches wide and ERS80S96 for 96 inches wide.

Generally, ramp doors are designed for enclosed trailers. When planning to reinforce or install a ramp door on a trailer, there are important precautions to take, an example is evaluating the interior dimensions of your trailer. Ramp doors are usually fixed, installed or modified by the original retail manufacturer by a certified dealer the torsion spring should never be modified or replaced by an end user. Importantly, the weight of the door and dimensions are the determinant for spring system assembly, the door weight is calculated and used to determine the right application. Ramp door springs are often standard 2" diameter but there are also other diameters like 2-5/8" diameter springs and 3-3/4" diameter springs.

The best assemblies for doors are those that have extra height with aluminum tread plate, sometimes steel tread plate, extra steel in the door and special flooring. Some floors are customized to enable them to lift heavier and taller doors. For a ramp door reinforcement, it is necessary to know the parts and equipment that are required to make one that fits best. They include; cables for enclosed trailers, ramp springs, spring latch, bolts and nuts, screws, cable drum.

Ramp door installation requires a series of processes which are outlined below;

Measurement of the internal width is taken, this helps in knowing the best fitting as in size of door to pick it out specifically for your enclosed trailer. Width measurement is the first step and parameter to know before Installation of you ramp door begins.

The spring tube is then cut aside creating an allowance of 1 diameter on both sides of the spring aside.

The next process is welding, weld 1-1/2" x 2" x 3" and mount the bracket to a header, 1-1/2" inch leg is welded and 2" leg extends into the trailer creating 4" clearance between the jamb and the 2" mounting leg. (" means inches).

Absolute checking of the cable drums, ensure that the drums that are stamped right hand are on the curbside and drums stamped left hand are on the driver side. Let the set screw be loose not tightened.

The spring assembly are to be bolted onto the mounting brackets with four 3/8" shoulder bolts provided.

Galvanized (coated or electrified) bearing plates are placed outside of the mounting angle to enable the shoulder of the bolt to fits in punched slots. Tighten the four nuts securely. Fix the end of the spring mounts on the curbside.

Mount the cable anchor bracket securely on-ramp with the bolts. Ensure the center line of the cable anchor pin should be at 9" from the top the of the ramp. The cable stop should be Installed in the slot of cable drums. All nuts and bolts should be properly tightened on mounting to avoid any of it coming loose.

Strengthen the vice grip on spring shaft at a minimum of 8" from the end of spring by holding it together tightly.

The Vise grip usually lies against the header to stop the shaft from turning which may result in alternate loosing of the nuts and bolts.

Now release the cable onto the drums starting from the right hand which is the curbside, set the cable under tension and hold in place with the setting screws. Then, move to the left side which is the driver side. Here, you also set the cable under tension and secure in place with screws. It is advisable to start with the right hand (the curbside), the reason is that the ability of the cable to come slack will be minimized.

At this point, tension is to be applied on the torsion spring keeping the ramp open, this process is called winding, and the most appropriate bars are the only 1/2" winding bars which are designed to help with full insertion into casting. It is important to take note of the size and seating or placement of the bars before carrying out the winding process. The winding process is a very critical process that needs to be carried out carefully with proper winding tools, if proper winding tools are not used, it can lead to rupture of the casting and can as well lead to harm or cause bodily harm. The winding process is carried out on spring by winding it down towards the floor.

There are various and different heights of ramps, turns can be approximated as ramp height, for example, 72" approximated 9.3 turns, 78" approximated 9.9 turns, 84" approximated 10.6 turns, 90" approximated 11.3 turns, 66" approximated 8.6 turns. Ramps are thereby often measured by their height or turns, both are appropriate.

Mount cable anchor bracket at 9" and set screws to wound properly, then tighten the screws immediately you are sure that the springs are wound properly.

The next step is to call off the grip from the spring shaft.

The last step and of course a very important one is the overall check, this is needed to ensure ramp is properly balanced. Also, check the turns to know if there's need for addition or subtraction in the name of attaining a balance. Move on to check the spring, an overwound spring will cause difficulty in opening the ramp.

After this process is concluded, you have your ramp safely and smoothly installed!

This is a service North Carolina Trailer Sales offers, and we keep rear ramp door cables, springs and hardware on the shelf. If you'd rather not wind a torsion spring yourself, book it with our service department or pick up the parts at our parts counter. You can also see the enclosed cargo trailers we have in stock.