drop axle rol center????

Hey gang.

My home built box trailer seems to wobble at hi way speeds its not swaying it side to side tipping. It has 2 4 inch drop leaf spring axles under it. I'm trying to find out where the roll center of the trailer is. With a straight axle i belive it's a line drawn between center of the front eye's bolt to the middle of the shackle where it passes over the axle but not sure on a drop axle. Anyone know? Got links? Got pict?

I'm thinking of adding panhard rods as high as possible to move the roll center closer to the CG and if i've got time some sway bars on the axles too.

44

44, are you running shocks? What you describe sounds a bit more like spring oscillation.

IIRC, to figure static roll center on a straight axle:

Start from the center of the front (fixed) spring eye bolt and measure across the trailer (lengthwise with the axle) to the axle beam's spring mount pad on the opposite side, like from top left to bottom right. Then do the same the other way (top right to bottom left), where the two lines cross is your roll center.

yes it has shocks unlike most trailers. The base trailer was a large tow behind RV. Body was gone before i got it (thankfully) over the winter i stuffed a fiberglass box truck box on the top.

Roll center on drop axles is the same as on regular axles, as near as I can tell.