Hi ! I need advices, Two 3500 lbs axles landscaping trailer 81 inches by 16 ft to be build . Am trying to avoid bad handling on the road , poor axles alignment, and bad load distribution. I wonder if the 60% rules is accurate, if I have to take the mesurement from the front of my frame or from the coupling point? Any better ways to find the optimal place to weld my suspension blade supports? Thanks in advance!
The 60%/40% deck rule is not always accurate. But it is ok for general use trailer. The measurement is taken from the front of frame (deck), not from the trailer coupling point, to the middle axle bracket from where the suspension equalizer is located. So, 60% of deck length is in front of axles and 40% behind the axles. Make sure the deck is squared and that the axle brackets are exactly at the same location on both sides and the trailer will track straight. For proper load distribution, make sure to front load the trailer first. If your tow vehicle can handle the added hitch weight, you can located the axles at 70%/30%. To get the exact optimal axle location, there is calculations that can be done (see the first video in this series), but those calculations assume the load is at the same location on the trailer deck all the time.