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5th Wheel Hitch With Maximum Height for Most Trailer-to-Truck Bed Rail Clearance  

Question:

I am a first time fifth wheel owner. I have a 2016 Ram 3500 4x4 MegaCab. The height of my bed rails is 59. When I measure the fifth wheel Im purchasing at level it is 57inch from the ground to the bottom of the front area top of the pin box and 11inch down from there to the pin. I have not purchased the hitch yet. I have factory puck system and 64inch bed. My concern is that I dont know how much squat Ill get when I hitch up. The pin weight of fifth wheel is 2600#. If the fifth wheel already sits 2inch below the top of my truck bed rails 57inch vs 59 how am I supposed to get 5-6inch of clearance and not have the fifth wheel be really nose high. I cant imagine Ill get more than 2-3inch of squat. The dealership says not to worry itll work out but they cant explain how. Please advise.

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Expert Reply:

Thank you for the photo of your 2016 Ram 3500's bed rail which sits 59-inches above ground. You are correct that the recommended minimum clearance between a bed rail and the underside of the trailer's overhang is 5 to 6-inches, as shown in the linked diagram. Since your trailer sits lower than your truck you'll need some height adjustment to tow safely.

By chance is your truck lifted? Lifted pickups are not ideal for 5th wheel towing for the reason you have already discovered. Even some non-lifted trucks can be tough for 5th wheeling if they have very large tires that bring the bed height up.

5th wheel hitches vary in their height range. You can select a hitch with a higher maximum height setting to provide clearance at the bed rails, but this will also require adjusting the position of the trailer pin box on its mounting wings, and also possibly lifting the trailer suspension with an over-under kit like # K71-385-00. The hitched trailer must be level. Lifting the trailer helps with leveling but it does raise the trailer's center of gravity, which tends to degrade handling by allowing more side-to-side motion.

With the trailer level, your ground-to-overhang distance should be no less than 5-inches more than your ground-to-bed rail distance. Please feel free to tell me the distance from the ground to the bottom of the trailer overhang when the trailer is level.

5th wheel slider hitches that fit your Ram 3500's factory puck system are shown on the linked page. Those with the greatest height come from Curt, such as their 16K hitch # C16521, which mounts in drop-in adapter # C16022. This provides up to 21-1/2-inches height above the bed floor.

If your Ram 3500 is a dually you will probably see little squat, say no more than an inch. SRW trucks might sag up to 2-inches, but this depends on whether your 2600-lb pin weight is the dry pin weight or your loaded pin weight.

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Adam R
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Michael A. profile picture

Michael A.

2/7/2020

The owner actually did give the distance from fifth wheel overhang to ground when level: 57 inches. Whats not mentioned is the fact that the truck bed is also high on a lifted truck, so finding a hitch with higher adjustment is not the answer. The trailer will be excessively high in front no matter what. Only answers are lowering the truck tires, or suspension spacer reduction, etc., or raising the trailer at its axles over-under kits, etc.. I just bought a new 2020 Ford F350 Tremor model, and have the same 59 bed rail height problem.

JasonS profile picture

Jason S.

2/10/2020

With a lifted truck you pretty much almost have to lift your 5th wheel trailer. I recommend using the Dexter Trailer Springs Over-Under Conversion Kit # K71-384-00 if you have 3,500 lb axles, or # K71-385-00 if you have 5,000-7,000 lbs axles. This then allows you to adjust the hitch height and the pin box height to achieve level. If you can't achieve level by using the over-under and adjusting the heights of the hitch and pin box, then removing the truck lift is your only option. The 59 inch rail height is common and the adjustment of the pin box and hitch height does make it compatible.
Michael A. profile picture

Michael A.

2/10/2020

We have visited several RV shops since buying the truck, and nearly all 5th wheels in the lot sitting level are about 59 from bottom of overhang to ground. No matter what you do with the hitch and pin box, the front of the trailer needs to be located higher than level by the 5 or six inches suggested for rail clearance not a lot, but a very obvious rake. The axle flip may be helpful for other reasons we sometimes go off the beaten path, and with this truck a slightly raised trailer may be appropriate.

JasonS profile picture

Jason S.

2/11/2020

Another option to raise it slightly is to use larger tires. As long as you have 4-1/2 inches on top of the tire to the wheel well and if you had dual axles at least a couple inches between the larger tires you won't have any issue with full suspension travel. We just looked at a wheel/tire size on a trailer yesterday to assist with a lifted truck that just needed the extra couple inches of height on the trailer.
Nathan L. profile picture

Nathan L.

3/18/2020

I just finished going through this with my 16 Ram 3500 SRW, pulling an older 30 Holiday Rambler with a pin weight of 1620 lbs. This caused the rear axle to 1.5 inches. Even with the trailer axles flipped,it wasnt enough. With your tongue weight of 2000 pounds, I wouldnt expect to see any more sag than 1-7/8 inch. There is a set of shims on the truck between the leaf springs and axle. These can be relocated above the springs to the rear approximately 1.5 inches. Its not a job for the weak of heart, as youre dealing with a lot of weight and heavily loaded springs. It can be done, and Im still alive to prove it!

ChrisR profile picture
Etrailer Expert

Chris R.

3/18/2020

Thanks for sharing your solution! It sounds like quite the undertaking but I'm glad you were able to get the needed clearance. Hopefully this helps another neighbor that comes along with a similar issue.
Walt N. profile picture

Walt N.

11/3/2021

I am looking at buying but can’t pull it away: My issue is , the 5th wheel RV is tall, a (2020 Genesis ) my 2013 F-350SRW sits as high as it’s going to sit from factory 52.5”ground to top of bed. The RV sits nose down and not but 2-3 inches space. ( that’s not hooked up but touching. curt hitch is 17”h, Can’t raise the hitch. It’s at its top. The 3 bolt pattern pin box doesn’t have much adjustment ( lower by 1 bolt height? Is there a extra tall set of legs? (Ford puck ) and the Genesis has a RotoFlex that is not compatible w my CurtQ24, so swap one or the other. Anyone else have this issue w new rv and older truck?

LesD profile picture

Les D.

11/5/2021

@WaltN Is your Curt Q24 a slider like our part number # C16545-16020 for Ford prep pkg? Or is it a fixed hitch like our Curt Q24 part # C16545-16017?
LesD profile picture

Les D.

11/5/2021

@WaltN Is your Curt Q24 a slider like our part number # C16545-16020 for Ford prep pkg? Or is it a fixed hitch like our Curt Q24 part # C16545-16017?
WaltN profile picture

Walt N.

11/5/2021

@LesD NO fixed Leppert says not compatible w RotoFlex because curt moves n all directions and moves the rubber pad out from its position on the RotoFlex.
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