fifth wheel hitch
should I buy hitch at dealer with fifth wheel purchase or have one installed before going to dealer ? thanks for any response
Forum Discussion
Cummins12V98,
Yes, I agree the chucking is coming from the hitch, but the motion of the hitch head is caused by angle change of the Trailair pin box lower jaw. The hitch head cannot move indepently of the pin box. Try holding a 12 ruler with one end resting on a table, hold the other end at a 45 degree angle to the table, let the end you are holding drop down 1 inch. You will observe the end resting on the table move away from the end you are holding by 1 inch. Why 12 inches, because the horizontal distance from the pin is 8.5 inches and the vertical distance from the jaw pivot point to the head pivot point is also 8.5 inches creating a 45 degree right triangle with an hypotenuse of about 12 inches. So when the pin box moves up 1 inch relative to the truck, the hitch head pivot point is jerked back 1 inch and vice versa. I have no problem with the design intent of either the Trailair pin box or the Curt hitch, it's just that they don't work well together. This system problem would not be as pronounced with other combinations. For example, the Trailair and the B&W Champion with a head pivot point just below the hitch head surface. Another example the Curt hitch with a Flex Air pin box with a second pivot point in the lower jaw.
Yes, I agree the chucking is coming from the hitch, but the motion of the hitch head is caused by angle change of the Trailair pin box lower jaw. The hitch head cannot move indepently of the pin box. Try holding a 12 ruler with one end resting on a table, hold the other end at a 45 degree angle to the table, let the end you are holding drop down 1 inch. You will observe the end resting on the table move away from the end you are holding by 1 inch. Why 12 inches, because the horizontal distance from the pin is 8.5 inches and the vertical distance from the jaw pivot point to the head pivot point is also 8.5 inches creating a 45 degree right triangle with an hypotenuse of about 12 inches. So when the pin box moves up 1 inch relative to the truck, the hitch head pivot point is jerked back 1 inch and vice versa. I have no problem with the design intent of either the Trailair pin box or the Curt hitch, it's just that they don't work well together. This system problem would not be as pronounced with other combinations. For example, the Trailair and the B&W Champion with a head pivot point just below the hitch head surface. Another example the Curt hitch with a Flex Air pin box with a second pivot point in the lower jaw.
