If towing a tandem axle trailer, do watch the height of the trailer coupling.
A poorly loaded, forward heavy loaded trailer can make the rear on the towing car sag, or a low towball height, this increases the load onto the front axle and in effect gives the trailer a tail heavy stance, which in turn can make the tail swing when going down hill.
This instability can vary greatly between slipper springs to rocker springs setups.
A correctly loaded tractor trailer, it has near 50-50% load sharing on the rear wheels of the tractor and the trailer wheels and this configuration is safe when braking going down a slippery slope as there is weight on the rear wheels of the tractor, which have only rear wheel braking.
https://www.aulro.com/afvb/images/im...015/03/731.jpg
A centre axle assembly with a slight load on the tractor drawbar.
https://www.aulro.com/afvb/images/im...015/03/732.jpg
Four wheel trailer with no load on tractor axles.
https://www.aulro.com/afvb/images/im...015/03/733.jpg
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