tandem axle weights

[jmtandem]

I have weighed my tandem trailer axles and they are not carrying the same weight. They are Dexter 3500 axles with the equalizer between the springs. The trailer sits level. Should they carry the same weights and, if not, how is the proper way to weigh each axle. I was using a tongue scale and putting it under each sping perch then gently letting that trailer axle take the weight using a floor jack. The number left/right are also different but I think I can understand why that happens, was just wondering why the tandem axles do not carry the same load (sort of) equally. Any ideas would be greatly appreciated and if I am weighing incorrectly that advice would be helpful as well. Thanks.

[SmokeyWren]

I don't know the "proper" way to weigh the axles, but using your procedures with a tongue scale is probably not very accurate.


Here's how I would do it:

Go to a truckstop that has a CAT scale. A CAT scale has 3 or 4 pads for weighing various axles on the truck and trailer(s).


Place the trailer on the scale so the rear axle of the trailer is on a scale pad by itself. Weigh the rig and don't worry about any of the scale pads except the one with just the rear trailer axle on it.

Pay for that weighing, then pull around and weigh the rig again, but this time with the front axle of the tow vehicle on one pad, the rear axle of the tow vehicle on a different pad, and both trailer axles on the third pad.

Subtract the weight of one trailer axle on a pad from the weight of both trailer axles on a pad. That will tell you how much difference in weight is on each of the two trailer axles.

That will give you a much more accurate indication of the weight on each axle.

The trailer may be designed so that the tandam axles have approximately the same weight only when the trailer is loaded, and with the payload properly distributed on the trailer.

[jmtandem]

Thanks.

[wingnut60]

Equalizers don't actually equalize weight on the axles--weight on each axle is determined by the Center of Gravity of the entire unit and where the axles are located in relation to the COG. The equalizers allow the tire/wheel assembly to move forward/backward up/down in response to road conditions.

Trailers and fifth wheels are designed with more weight on the front of the unit than on the rear to improve towing/reduce sway. This will automatically bias the weight on the axles toward the front axle. And side to side weights are usually biased toward the side with the refrigerator/stove by their weight.

You should weigh your tow vehicle and get axle weights when not hooked up, but loaded to tow. Then repeat the weighing with the trailer--this will get the pin/tongue weight, and gross weights and you can see how weight transfers when trailer is hooked up.

Joe