mkirsch wrote:
I've researched this myself extensively. There doesn't seem to be an official de-rating guide for hitch extensions. I suspect that the receiver manufacturers don't want to chime in out of liability fears, "We never said it could be used with an extension, so you're on your own." Except of course Torklift...
Some people will tell you that your extension is de-rated 50% no matter how long the extension is, but coming from an engineering background I know that's pure baloney. Most likely you are limited by the capacity of the extension itself rather than the de-rated receiver, but while my engineering concepts are still good, my finite element analysis skills are rusty as 20 year old truck.
I personally run a homebuilt extension that IIRC gives me around 16" of extra length. It's just a 24" Curt "weldable receiver tube" with an extra cross hole drilled in it, and two 15000lb D-rings welded on to it for safety chains. Short safety chains secure the D-rings to the factory receiver, and then the trailer safety chains attach to the D-rings. I've always wondered what the rating/capacity on this extension would be.
This was a site that helped with perspective. As always with engineers, use a pinch of salt.
TC and hitch/weight info site.....
