How to Determine the Correct Position for B&W Pivot Arms

Updated 11/05/2025 | Published 01/03/2025

Question:

How can I easily calculate pivot arm position by measuring the pinbox base plate height and the truck bed? Rails are already in place just need to assemble the slider. Would you just subtract bed from pin box and add 5-6?to get slider height?

asked by: Galen D

Expert Reply:

Galen, I'm actually not sure how you'd calculate that by using the base plate height and the truck bed. To find out the horizontal position of the pivot arms you are supposed to measure the distance between the center axle and the bumper, and the king pin to the body of the 5th wheel. If the difference is 16"- 24" then you can place the pivot arms in the "over axle" position. If it's less than 16", then you can place the arms behind the axle. Finally, if it's more than 24", then you can place them in front of the axle.

expert reply by: Bryce D

Jameson C.

11/3/2025

Hey Galen, how did things go with setting the pivot arm position on your B&W Companion hitch? Did those axle and king pin measurements help you figure out the right placement? Your update could make it easier for others setting up the same hitch.

Galen D.

11/5/2025

@JamesonC Yes it did thank you! I'm still curious if there's an easy formula to tell how high to set the pivot arms. Since they have a height adjustment do the have a total height for each position. Then I could measure from the bed/ floor panel to the sides/ top rails and then measure from the base plate to the nose of the trailer and Be able to determine which height position to install the arms. A couple of times we've ended going to hook up and realize it need to come up or coulda gone down to travel more level. The fun of last minute.. pull off the upper.. undo bolts.. then re-torque all of them would be nice to avoid.

Jameson C.

11/5/2025

@GalenD You can measure from the ground to the pin box of the trailer (not the king pin) when the trailer is sitting level and then compare that to the distance from the ground to your truck bed height. The difference between those two dimensions is the height you need the hitch to be. The hitch height range of the Companion part # BWRVK3710 so that will give you an idea if you need to be on the taller or shorter side of the arm height range.