Do you know 5th wheels? Drawbar pull, is not the same as GCW

Gary Hey
Jun 19
2 min read

Manufacture, model, Fixed, moveable fixed, slide length, +/- forward/rear location, leg height/plate height, handle location/air release, No-Tilt/Convertible/Pinned, ramps, inboard/outboard mounting, Kompensator, Teflon, no lube, light weight, consider landing gear/trailer drop, (which no OEM accounts for), 2”/3.5”, safety lock, Light/Severe/Heavy Duty, Square or taper type, 2” or 4” slide notches, Air/Light line consideration, Application, etc.

Rule of thumb. 1” of slide, adds/subtracts 150 lbs on a 12K/34K steer axle, so a 2” slide notch = 300 lbs. If 20K/40K, then 200 lbs or 400 lbs/per notch.

Over specing the slide length fwd position will affect frame strength calculations, so use the sales tool calculator. Engineering assumes worst case.

How many locations load the axles to 12K/34K? ONE, which also matches every other example, so why move the wheel? Ground loading may not be the only concern. Ride, aerodynamics, weight distribution, Looking GOOD, etc. Added component’s location and weight may affect the position.

Flatbed example can find the load positioned forward of the trailer nose which effectively grows the King Pin setting; thus, a negative wheel location moves the trailer rearward.

Email questions (stay anonymous). You don’t know what you don’t know. The best thing is to attend our 2 ½ day class or at least access eLearning and use GURU. Our promise is to leave the industry better than when we arrived.

56 specific Vocational chassis

Cold call specing on your phone or tablet.

www.zfactorconnect.com.

It generates a 15-page report by answering 38 questions tied to the application. Email a copy before leaving the customer. Customer collaboration significantly cuts down on time lost due to misunderstanding and improves conversion.