Ramp Door Maintenance: Springs, Cables, Hinges and the Seal

The ramp door on an enclosed trailer is a heavy steel-framed panel on a piano hinge, held up by a spring assist and closed by two or three latches. It gets opened and slammed hundreds of times a year, sits in the weather, and takes the weight of everything that rolls over it. Most owners never look at the hardware until the door gets hard to lift or refuses to latch. A few minutes a couple of times a year keeps it working and keeps a spring from letting go on someone.

The spring assist

Most ramp doors on our lot use a spring-assist system inside the door or along the hinge that carries most of the door's weight so one person can raise it. The spring does not last forever. The first sign it is weakening is that the door feels heavier to lift than it did, or that it drops the last foot instead of settling. When that starts, get it looked at rather than muscling it. A spring that fails under load can let the door fall, and on an 8.5-wide with a tall door that is a serious amount of steel.

Do not try to adjust or replace ramp door springs yourself unless you have done it before. They are under considerable tension and need the right tools and a second person. A trailer shop does it routinely.

Cables

Doors with cable assist run a cable from the door to a spring or drum on each side. Look at the cables every time you notice them: frayed strands, a kink, rust at the end fittings or a cable that has jumped its pulley. A cable that is starting to fray on one side puts all the load on the other, which is how you end up with a door hanging from one cable. Replace them in pairs.

Hinge

The piano hinge along the bottom of the ramp is where grit collects and where the door binds first. A few times a year, sweep it out, hose it and put a dry lubricant along the full length; a wet grease attracts more sand. Open and close the door and listen for a squeal or a click that means a section is binding. A hinge that has been forced by a door dropped at an angle will show a gap at one end, and that is worth having looked at before it tears.

Latches and the flushlock

The latches on the sides of the ramp pull the door tight against the seal. Check that each one closes with the same effort; one that is loose is letting water in and one that is tight is bending the door. Lubricate the flushlock cylinder with a dry lock lubricant, not oil, so it does not gum up in the dust. Our post on door seals and latches covers the adjustment.

The seal and the threshold

The rubber seal around the ramp opening is what keeps road spray out of the trailer. Look for cracking, flat spots and sections that have pulled away from the channel. A seal that is failing shows up as a wet streak on the floor just inside the door after a rainy drive. The threshold at the bottom takes the weight of everything rolled in; check that its fasteners are tight and that the ramp's edge still sits flush against it.

Using it without hurting it

• Lower the door with a hand on it. Letting it fall bends hinges and shocks springs.
• Do not exceed the door's rated load; a heavy machine needs the upgraded ramp, not a hope.
• Use ramp extensions or blocks for low cars so the car's weight is not all on the lip.
• Keep the door closed and latched when the trailer is parked; an open ramp in wind is a sail.
• Do not use the ramp as a work platform for a jack or a press.

Most of this takes ten minutes twice a year and fits into the routine in our maintenance checklist. If a ramp door is being asked to carry more than it was built for, the options list shows the heavier ramp packages, and it is worth ordering the right one when you spec a build rather than fighting a standard door for years.