Hitching a Fifth-Wheel and the Checks Before I-10
A fifth-wheel that drops off the hitch or drags a locked brake ruins a trip in the first mile. The hitching routine and walkaround that catch it early.
The worst fifth-wheel problems happen in the first mile. The pin was not locked and the trailer drops onto the truck bed at the first stop sign. The brake controller was not connected and the first hard stop on Highway 90 is a truck being pushed by ten thousand pounds. The tire that was low in the driveway blows before the on-ramp. Every one of those is caught by a routine that takes ten minutes.
Here is the routine, and the reasoning behind each step.
Hitching: the part that gets rushed
- Trailer chocked, landing gear at the right height so the pin box is just above the hitch plate. Too low and you lift the truck; too high and the pin rides over the jaws.
- Tailgate down or removed, hitch jaws open, hitch handle in the ready position.
- Back under slowly and straight. Listen for the jaws to close. Stop.
- Get out and look. The jaws should be fully around the pin, the handle in the locked position, and the safety pin or lock through the handle.
- Tug test. Trailer brakes applied by hand on the controller, or chocks still in place, and pull forward gently. The trailer should hold the truck.
- Only now raise the landing gear. Connect the breakaway cable and the electrical plug. Remove the chocks last.
The step people skip is getting out to look. A hitch that sounded like it closed can have the jaws closed in front of the pin. It will hold through the tug test on some hitches and then drop the trailer on the first real bump. Looking at the jaws is the only check that counts.
Never raise the landing gear until you have looked at the jaws and done the tug test. If the hitch is not locked, the landing gear is the only thing holding the trailer up.
The electrical plug
The seven-pin plug carries the trailer brakes, the lights, the charge line to the trailer battery, and the breakaway. A plug with a corroded pin gives you a brake controller that reads no connection, lights that work on one side, or a trailer battery that never charges. Plug it in, then check that the brake controller shows a trailer connected, that all the lights work with a helper, and that the trailer brakes respond when you apply the controller by hand. We covered the wiring side in Trailer Lights Out: Working Backward From the Plug, and the brake side in Travel Trailer Brake Problems You Shouldn't Ignore.
The walkaround
- Tire pressure with a gauge on every tire including the truck, set to the load. Look at the sidewalls for cracking and check the date codes if the tires are more than a few years old.
- Lug nuts. A trailer that has had a wheel off recently needs its lug nuts re-torqued after the first miles. Loose lug nuts on a fifth-wheel are a common cause of the wheel-off failure.
- Slides in and locked. Awning stowed. Antenna down. Steps up.
- Underneath: anything hanging, a spring hanger cracked, a shock loose, an equalizer worn. Look at the suspension the way we described in Fifth-Wheel Suspension Issues.
- Hubs. Put a hand on each hub after the first few miles. One that is much hotter than the others is a bearing or a dragging brake.
- Breakaway cable attached to the truck, not to the hitch or the safety chain loop, with enough slack for turns.
The first stop
Ten miles in, pull off and walk around again. Feel the hubs, look at the tires, look at the hitch. This is when a wheel that was not torqued shows itself, when a bearing that was dry starts to warm up, and when a brake that is dragging has heated a drum. It is the cheapest inspection there is and it catches the problems that would otherwise show up at seventy on I-10 between Milton and Crestview.
What a mobile crew does for a fifth-wheel
Tires, brakes, bearings, wiring, suspension, and the pin box and hitch side on the trailer, wherever it is. If you would rather have someone go over the rig before a long trip, that is a normal call to the driveway or the storage lot. If something goes wrong on the road, the crew comes to the shoulder or the campground. Details on RV and camper service are on the services page, and our post on RV roadside assistance on I-10 covers what happens when the call comes from the interstate.
Frequently asked questions
How tight should trailer lug nuts be?
To the torque the wheel and trailer maker specify, in a star pattern, with a torque wrench. Re-check after the first miles any time a wheel has been off.
The brake controller says no trailer connected. What do I check?
The plug pins on both sides for corrosion, the ground pin especially, and the breakaway switch. If the plug is clean and the controller still shows nothing, the trailer's brake wiring has a break.
Can you check over a fifth-wheel before a trip?
Yes. Tires, brakes, bearings, and wiring on site, at the driveway or the storage lot.
How often should fifth-wheel bearings be serviced?
Follow the axle maker's interval, and treat a hub that runs hot or a wheel with play as a reason to service them now rather than at the interval.
Fifth-wheel trouble anywhere on the panhandle, in the driveway or on the road? Call Duckett Roadside Repair at (850) 495-0366. Dispatch is answered 24 hours a day.