Boat Trailer Vibration

I have a Ranger 198vx with a single axle trailer. When I'm going down the road about 58-59mph it has a strong vibration to it, but it's only at that speed. I have rotated and balanced every tire on the trailer including the spare. I have switched tires out with the spare and every configuration I think of. However, it still has the vibration. Any suggestions? I just bought the boat new last year. SHould i contact Ranger or what? My local ranger dealer doesn't seem too interested in helping because I didn't buy it from them.

Some possible solutions.--Would check my tow vehicle tires and bearings.Had 2000 model Chevy pulling boat that did same thing.Found a bad right front wheel bearing assembly,fixed it,stopped the trailer vibration.Can't explain it,but it fixed problem.Might check trailer bearings also.Have seen bent trailer axle cause vibration,but mostly on an empty trailer.Also remove rims from trailer and check for dirt or rust buildup on hub face.If rim doesn't mate flush with hub can cause problem.Good way to check for good fit between rim and hub is to burn a sooty rag around hub,thoroughly covering hub with soot,put rim on,torque to factory specs and then remove .Look for a good rim pattern on hub.Another possibility (remote at best) is a caliper or brakeshoe dragging a little ,causing a little tire hop.Also jack up trailer, 1 tire at time,then get a good solid object next to tire,take a straight edge and hold close to edge of trailer rim and spin rim to check if rim is running true.Would detect a warped rim.


Quick way to eliminate your tow vehicle as a cause would be to get a buddy to pull trailer and see if it still vibrates at same speed.

Thanks for the info. I have towed with 3 different trucks and it still vibrates. I will look into the other suggestions. Thanks

Tandem axle trailer. Double check distance between front and rear axle on both sides of the rig, insure axles are parallel to each other and are perpendicular to trailer frame rails. Slightly kanted rear or forward axle can act much lke a car with a front end align ment problem, generating a vibration at selected speeds.