What causes this ?...............

[HEMI®Dart]

I see this all the time on the highway. It's usually a pop-up camper or medium, or small sized trailer.



The trailer will go from side to side. Kind of wobbleing . The tow vehicle is going in a straight line.



If had a nickel every time I've seen it... ... .....

 

[QRTRHRS]

IMHO, not enough weight on to stiff a suspension with little bitty wheels. Ever see a small cement mixer with no springs and small wheels bouncing down the highway behind a truck? And your hoping the thing is anchored real well.

 

[Extreme1]

It's caused by not enough toungue weight. Toungue weight should be 10-15% of the gross trailer weight. If you get much below 10%, $^it starts to happen. We saw a ton on our trip to CA.



The vehicle owner probably wants to keep from sagging the rear of the tow vehicle (like last time) and so they load all the junk in the back of the trailer. Above 45 or 50 mph sway starts. The really dumb ones just drive through it.



Several years ago I loaded up our snowmobile race trailer for the summer and drove it to the storage place. Top speed 45. I can't believe it when I see those idiots flying along with their trailers whipping.

 

[JyRO]

trailers whipping

Not enough tongue load is correct. And not only that, but when the front of the trailer is too high, in other words, the trailer is not being towed level, this whipping can happen. And man, get both of those going at the same time (not enough tongue load and front of the trailer up) and man lookout!



With the trailer up it throughs off the proper castor or camber (I forget which one, or if its both, off hand) needed for good tow-ability. Usually this is more specific with the smaller/lighter trailers.



- JyRO