Calculating 5th Wheel Turning Clearance

Updated 08/05/2020 | Published 03/25/2019

Question:

can you explian how to measure to make sure i will have enuf clearance from cab for a specific trailer please advise thanks

asked by: Travis O

Expert Reply:

The formula to determine 5th wheel turning clearance is pretty straightforward and is expressed as:

(A + B) - C = Clearance

A = Distance from center of fifth wheel hitch jaw to truck cab
B = Length of Sidewinder arm (22-inches) as with part # RP34FR
C = Width of trailer divided by 2 (to get half)

For an example, if the distance from the center of the hitch to the cab is 36", 36" + 22" = 58". If your fifth wheel trailer is 102" wide, take half (51"), then plug in: 58" - 51" = 7" of clearance. At least 4 inches of clearance is recommended to safely execute a 90 degree turn.

You can refer to the linked article for additional information.

expert reply by: Adam R

Dean B.

7/28/2020

I have a 2019 Ram 3500 standard short box (6'5") and pulling a 2021 Grand Design Reflection 150 Series 260RD. I have the new M5 fifth wheel hitch from Reese with the centre box turned to push the head a little to the rear of the truck (as noted in your video). The M5 hitch was recommended because the wedge that's supplied by Grand Design fits this hitch when using the the turning point feature on the trailer. Everything is set up to use the turning point but I'm finding hooking up not a easy as a standard set up. I'm wondering since the M5 box is turned would I have enough clearance if I moved to a standard set up? Thank you!

Jon G.

8/5/2020

I have heard that it can be a little difficult hitching up to pin boxes that have rotating turrets and that it takes a little bit of getting used to. You can potentially lock out the Turning Point pin box and use it like a standard pin box but you'll first want to use the formula mentioned above to see if you have enough clearance for a 90 degree turn. In your case you'll just take A - C = Clearance. If you have at least 4" of clearance then you'll be good to go.