Is my truck overloaded?

Rear squat, sway, braking and light steering are the signs. The check is arithmetic: everything in the truck plus tongue weight against your payload capacity.

Updated September 12, 2026

The signs

An overloaded truck usually tells you before you look up a single number. The rear end squats, and the headlights that used to level out down the road now aim up into oncoming traffic. Steering goes light and a little wandering, because an overloaded rear end lifts weight off the front tires that used to keep the truck planted. Braking distances stretch out — more weight takes longer to stop no matter how good the brakes are. Tires run hot to the touch after a few miles, because they’re flexing harder to carry a load past what the sidewall was built for. And if there’s a trailer behind it, the trailer starts pushing the truck through corners instead of following it, a shove you feel through the wheel on anything but a straight line.

Why the signs come late

None of those signs show up right at the limit, which is exactly what makes overload dangerous to judge by feel. Springs compress gradually and tires flex rather than fail outright, so a truck can carry several hundred pounds past its rating and still feel mostly normal on a calm drive to the grocery store. The signs above tend to show up closer to serious overload than to the actual limit, because springs and tires have some built-in tolerance for a little too much weight. What doesn’t tolerate it are the frame, the axles, the brakes and the tire ratings underneath all that tolerance — the parts that don’t bend gracefully, they just wear out faster or fail outright, and none of them announce themselves early.

The check is arithmetic

Waiting for the signs means finding out after the fact. The reliable check is arithmetic, not feel, and it runs in three parts. First, everything riding in or on the truck — people, cargo, and the trailer’s tongue weight — added up against the truck’s payload capacity. Second, the trailer’s own loaded weight against its own GVWR, a separate limit that has nothing to do with the truck. Third, tongue weight as a percentage of the trailer’s loaded weight, checked against the healthy range: 10–15% for a bumper-pull trailer, 15–25% for a fifth-wheel or gooseneck’s pin weight. The app checks the same 10–15% / 15–25% range — computed against the trailer’s GVWR — the calculator does this when you’ve entered one, the app always does — so its figure can read a little lower than the true loaded-weight percentage. Three numbers, three limits, and none of them require driving anywhere to compute.

Worked example

This truck has a 7,050 lb GVWR and a 5,150 lb curb weight, for a payload capacity of 1,900 lb. Add 1,000 lb of people and cargo and an 1,100 lb trailer tongue, and that’s 2,100 lb pressing against a 1,900 lb capacity — 200 lb over, which is enough to flip the check from green to red no matter how the truck feels on the way out of the driveway. The tongue weight itself checks out fine on its own: 1,100 lb on an 8,500 lb trailer is 1,100 ÷ 8,500 = 12.9%, right in the middle of the 10–15% range a bumper-pull trailer should land in. That’s the trap in a case like this one — the tongue percentage passes, the trailer might be within its own GVWR, and the truck is still 200 lb over because payload is a separate limit that doesn’t care that the other numbers look fine. An 8,500 lb trailer is also, on its own, likely past what a half-ton’s payload and tow rating leave comfortable room for — worth rechecking on its own terms even after the payload math above is fixed.

What to do

Weighing the truck settles the question a lot faster than adjusting mirrors and squinting at the rear bumper. A CAT scale gives you a real reading in two passes: the truck alone, then the truck hitched to the trailer with the trailer’s axles on their own platform — a CAT scale reads each platform separately. Unhook the weight-distribution bars for the second pass. Tongue weight is the truck’s total in pass two minus pass one; trailer weight is the trailer-axle platform plus that tongue weight. That separates truck weight from trailer weight from tongue weight, all from numbers a scale printed rather than numbers estimated by eye. If the check comes back red, the fixes are straightforward even if they’re not always convenient: move cargo out of the truck bed and into the trailer if the trailer’s own GVWR has room for it, since only the tongue portion of trailer cargo counts against the truck; carry fewer passengers on this particular trip; or hitch up with a different tow vehicle that has more payload capacity to spare.

Tires and GAWR

GVWR is a total, but the rear axle carries more than its even share once a trailer’s tongue weight is added. Without a weight-distribution hitch, tongue weight lands on the rear axle — and because the ball sits behind it, the rear axle picks up more than the tongue weight while the front axle sheds some — rather than spreading across front and rear the way an empty truck’s own weight does. That means a rearGAWR can be exceeded while the truck is still under its GVWR — the total looks fine while one specific axle is over its own separate rating. Rear tires face the same math: a heavy tongue pushes more weight onto the same two tires that are already carrying most of an empty truck’s rear-axle share, and a tire run consistently near or past its load rating is the tire most likely to run hot to the touch — one of the signs this page opened with, and a reason to check GAWR and tire ratings even when the GVWR total comes back green.