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Trailer Axle Weight Rating?


Feb 2, 2021
We just bought a 7x12 flatbed trailer and I'm wondering about the weight rating.

It has a drop axle and under-slung suspension. The axle is 1.5" square. I've seen a lot of stuff online saying 1.5" axles are often rated for 1,000 - 2,500 lbs. But, square is usually more sturdy than round, and this axle seems more solid than a lot of modern tube axles. The seller said it was solid and had a weight rating of 2,000 or 3,000 or so. I couldn't find any VIN, manufacturer plate, weight rating, etc on the trailer frame. We will be loading it with between 2,000 - 2,500 lbs so it needs to be reasonably sturdy, not just a light-duty trailer for hauling a few dirt bikes.

- Based on the axle, spindles, and hubs, how much could this trailer handle?
- Is there a simple way to improve the weight rating or reinforce the weakest link?
- Is there another way to get more info about this trailer?
- Any way to tell how solid the axle is / how thick the tubing is?

For reference, I was also looking at this thread, which is relevant to my situation:
2" solid square steel trailer axle weight capacity?


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Dec 21, 2012
Brisbane Qld Australia
if your drop axles are made from the cut off steerring pivot ends of an old KB1 Inter,as pictured then I doubt they are even legal......in any case ,new car trailer axles and hubs are so cheap ,just replace the lot ,and be happy.


Oct 3, 2004
LeClaire, Ia
That axle isn't from a KB, it IS an actual made-for-purpose trailer axle, probably solid, rather than Tubular steel, probably manufactured by Dexter, or one of their competetors. Most likely heated and bent in a jig in five places- two at the drop on each side, and one in the center to establish wheel camber.

The trailer chassis was probably a Glamper or Shasta mini-camper. The wheels recessed into the siderails is a dead giveaway of it's lineage, and the frame shape and size, axle location, and A frame front angle confirm. Hub bolt pattern is small, probably 4 on 4.5" bolt circle, but campers often replace the ubs with automotive pattern hubs simply because a 14 or 15" automotive tire and wheel combination was cost effective and sufficient for light camper duty.

The axle, when new, was probably rated in vicinity of 1500-2000lbs, but at this point in time, I would NOT ask more than 800lbs from it. If you find any drain holes in it, it's tubular, rather than solid, and is most likely much thinner due to internal corrosion, than you think.

The chassis was intended for walking loads, a light wood frame with sheet metal skin, and simple plywood interior- applying heavy loads would not be confidence-inspiring.

BT Fabrication

Nov 3, 2019
Ontario Canada
1000% it is a 2200Lb trailer axle.
leaf springs are 1.75" wide 4 leaf. those only hold 1100lbs each max
trailer probably only weighs a couple hundred lbs.

as said above, check the side wall of the tires, there is a rating per tire on them also.
so 2000lbs probably minus 400# leaves you with about 1500lbs MAX! over shoot this and you will blow out bearings or worse on old trailers, snap the axle clean off due to rust in the tube.
overloading it will be a recipe for disaster


Hot Rolled
Oct 13, 2009
Olympia, Wa
I have hauled a 2500lb load on a small 4x8 trailer with a 3500lb axle, but 1.5" seems like a tiny axle more for jetskis and 4 wheelers


Oct 10, 2009
Those solid square axles seem to have been popular in the northwest long ago. The straight ones seem pretty stout. I have some 2" solid axles under one of my trailers and they have taken some big overloading at times. That said, the drop axles like the ones this thread is about don't fair so good. I have not had a trailer with those style axles that didn't have bent axles.

If I had that trailer I would not put more than 3000 lbs on it and expect the axle to survive.