Poorly balanced wheels, too stiff a suspension, just a bad road in general.
What type of truck and trailer? For all I know, you could be talking about a Ford F650 and a single axle utility trailer. If you're referring to Class 8 vehicles, something like a single axle tractor towing a single axle trailer would be allowed an interstate GVW of 52,000 lbs.
Gross 52,000 lbs
Mini trucking? That's a new one on me. You might be thinking of what's referred to as "hotshot" trucking, which is a single axle trucking pulling a multi-axle trailer. This can be anything from a one ton pickup pulling a gooseneck trailer up to a single axle tractor-trailer power unit pulling a semi trailer.
Well, you're limited to 20,000 on the single axle. If you have at least a 35 ft. bridge to the trailer tandems, you can gross 34,000 on the trailer tandems (or 40,000 if you have a 10 ft. spread between the axles). As a rule of thumb, 12,000 is going to be your limit on the steers.
A single axle utility trailer measures 12'x77" and a tandem axle utility trailer measures 16'x77". In the USA, a utility trailer can be no taller than 13 ft. 6 inches.
A tandem truck usually refers to the amount of axles on the trailer or tractor. A single drive axle on a tractor would be referred to as a single, or the same for one axle on the trailer. I have seen it referred to the amount of tires on the end of an axle. When there are two tires on the end of the axle, that would be referred to as a dual, not a tandem.
A small single axle trailer does not need brakes but be aware that your vehicle will have to stop the vehicle plus the trailer, so allow more stopping distance. A double axle trailer needs trailer brakes if you are carrying a heavy load of any kind at all.
An 18' Aluminum Single Axle Trailer is 575 lb.Bruce at All American Trailers
The definitive answer is...it depends. Very few trailers are made with axels of 2000lb (or less) capacity. Most are 2500 to 5000 llbs (per axle). So if you have a dual axle trailer with two 3500 lb axles you can haul 7000 lbs MINUS what the trailer weighs. I have a single axle 6X12 with a single 3500 lb axle. The trailer weighs approx 500 lbs, so I would feel relatively safe hauling a 3000 lb load.
ABOUT 23,000 LBS ABOUT 23,000 LBS
A few trailer spindles bolted on to the axle but most spindles are welded to the axle.
12000 pounds