📋 Quick Facts
Time
4 minutes
Difficulty
Easy
Tools
2
Cost
$0
Trailer wheels fall off. Couplers come unlatched. Lights stop working between gas stops. The pre-trip walk-around is the single most effective accident-prevention habit in towing. Here is the list, in the order you should do it.
⚠ The 50-mile re-torque ruleEvery trailer manufacturer says to re-torque the lug nuts after the first 25-50 miles of any trip and again after the first 200 miles. New owners ignore this and wheels separate from trailers. Keep a torque wrench in the truck.
📝 Step-by-Step
- Coupler latch and pinLatch fully down on the ball. Locking pin or padlock through the latch so it cannot lift on a bump.
- Safety chains crossed and shortCrisscrossed under the tongue, just enough slack for sharp turns, hooks pointed inward so they cannot bounce off.
- Breakaway cable attached to the truckCable looped through the receiver or bumper hole - NOT the safety chain. If the trailer disconnects, the cable pulls the breakaway switch and locks the trailer brakes.
- 7-pin or 4-flat lights testedLeft signal, right signal, brake lights, marker lights, hazards. Have a helper confirm.
- Trailer tire pressureInflate to the sidewall max (not the door jamb). Look for sidewall cracks, scalloping, and missing tread.
- Lug nuts torquedTrailer wheel bearings and lug nuts back off over time. Carry a torque wrench - retorque after the first 50 miles of every trip.
- Wheel bearings cool to the touchTouch each hub before pulling out. Then touch again at your first stop. A hot hub means a failing bearing - do not drive on it.
- Tow vehicle tire pressureMany trucks specify a higher rear pressure when loaded. Check the door-jamb sticker.
- Engine oil, coolant, transmission fluidTopped off, no leaks. Trailering doubles the heat load - run extra capacity at the top of the dipstick range.
- Brake controller power and gainPower light on, gain set for the loaded trailer (test before highway speed).
- Mirrors and load securedMirrors out, cargo strapped (NOT bungee corded), tarp tight.
🔗 Related Towing Guides
❓ Frequently Asked Questions
How often should I check trailer tires?
Pressure before every trip; tread/sidewall every trip; temperature at every stop. Trailer tires are speed-rated and time-aged - replace at 5-7 years regardless of tread depth.
Do I need to check fluids more often when towing?
Yes. Engine oil, ATF, and coolant all run hotter under load. Check before every trip, and have an aux transmission cooler if your trailer is over 50% of tow rating.
Should I use a weight scale before leaving?
If your trailer is loaded heavy or has shifted, yes - a CAT scale at any truck stop costs about $12 and confirms axle weights, GVWR, and GCWR are within limits.
What if a light is out?
Fix it before you leave. The most common cause is a dirty 7-pin connector or a corroded ground wire on the trailer frame. Brush the pins with a wire brush and apply dielectric grease.
How do I know if my hitch is the right class?
The receiver is stamped with its class (II, III, IV, V) and its rated weight - both gross trailer weight and tongue weight. Pick the lower of (receiver rating, ball mount rating, ball rating, vehicle tow rating).
Do I really need a breakaway switch?
Yes, and most states legally require it on trailers over 3,000 lb GVWR. If the trailer disconnects, the lanyard pulls and the trailer's onboard battery locks the brakes - which is what stops it from running into traffic.