Will Gooseneck to Fifth Wheel Adapters Fit a Fifth Wheel Hitch on a Kenworth Over the Road Tractor

Updated 02/17/2012 | Published 02/14/2012

Products Featured in This Question

Gooseneck to 5th Wheel Trailer Coupler Adapter - Inner Tube - Square - 25,000 lbs

(853)

$211.98

Gooseneck to 5th Wheel Trailer Coupler Adapter - Inner Tube - Round - 25K lbs

(853)

$177.45

Question:

I have an over-the-road Kenworth tractor that I want to use to pull a gooseneck trailer while hauling large round hay bales. The Kenworth has a standard fifth wheel. I dont really know what size kingpin is standard for over-the-trucks and trailers. I see these neat adapters but cant really tell if they will work for an over-the-road tractor.

asked by: Steve O

Expert Reply:

The most common size for a kingpin that fits a fifth wheel hitch is 2 inches in diameter. We have checked the kingpins on some of the truck trailers here on our lot and they measured 2 inches. I would recommend to measure the opening on your fifth wheel hitch with the jaw(s) closed to see if your Kenworth tractor will fit a 2 inch diameter kingpin.

The gooseneck to fifth wheel adapters will come in either a square tube design or a round tube design. You will need to choose the adapter to fit what design tube is on your gooseneck trailer.

The Gooseneck to Fifth Wheel Trailer Adapter - Square, part # KPG5-Q25-IP, has a 2 inch industry standard kingpin. If your Kenworth semi fifth wheel plate accepts a 2 inch kingpin, and has a square outer tube on the gooseneck trailer then this adapter will work. This adapter is designed to fit as the inner tube on most standard gooseneck square tubes. It has a 4 inch square outside diameter.

I also have the Gooseneck to Fifth Wheel Trailer Adapter-Round, part # KPG5-R25-IP. It has a 2 inch kingpin and is designed to fit as the inner tube on most standard gooseneck round tubes. It also has a 4 inch round outside diameter.

expert reply by: Jeff D