Pin box clearance

[chucksenough]

Long-time reader, first time poster - TIA.

We just bought a F-350 (6'8" bed) with a 38' 5th wheel. We have a 20k Reese slider hitch (30084) installed. The 350 is the king range with 20" wheels. It sits high. As is right now, the front top of the trailer is a few inches higher than level. Unfortunately, the pin box doesn't clear the bed - it probably needs 2.5" more to just clear, plus maybe an inch or two for safety?

I have a few adjustments that can be made - the height of the reese can come up as it's on the second lowest of four settings. Also the pin box can be adjusted down one setting giving about 3" (it's a long style pin box). The problem is with either of these adjustments, I would gain maneuverability but also increase drag beyond an already unleveled trailer.

Advice? I've got it at a welder who wants to adjust the pin box height and then shave a little of the back end off. I have a feeling that idea is going to be heavily criticized...

[drdarrin]

You want at least 5" of clearance between the bottom of your 5er and the bed rails of the truck. More is better. Up to 8" or so. Less and there's gonna be some rubbing and banging.

Then level the trailer as much as you can. That may involve flipping the axels on the trailer or lowering your trucks height, or both.

Tall trucks and nose high trailers are not uncommon and in some cases, unsafe. The higher the nose, the more weight is shifted to your trailers rear axle. You don't want to be that guy with the blown out rear tires or failed axle on the side of the road.

[dayle1]

It may be time to consider putting a sub-frame under the fiver. Either 4" or 6" box steel with crossmembers which will both strengthen the frame at it's weakest area and prevent it from twisting as well.

[Old-Biscuit]

Pin box mount that does not bolt to/support the extended pin box can be cut off to increase 'turn radius' clearance so back of pin box mount does NOT make contact with truck side walls etc







AS for making 5th wheel tow level....
Hitch adjustments UP, Pin box adjustments DOWN.
If that does NOT result in enough bed rail clearance and level 5vr then you look into an alignment kit that results in raising trailer 2" when installed
Correct Track™ Suspension Alignment System

And 'axle flip' ---moving leaf spring packs from under axles to top of axles (if not already on top of axles)




If axle flip does NOT achieve enough lift to tow level then subframe install will be necessary
Involves cutting leaf spring hangers off of trailer frame, welding on square tubing in height needed (3", 4", etc) to level tow, then welding spring hangers back on and adding cross square tube supports




New trucks taller, 5th wheel end up nose high....so owners HAS to ivest in means necessary to level tow.

Good luck!

[SmokeyWren]

Old-Biscuit gave you the strait skinny, so pay attention to him.

When all is said and done, you want the floor of the trailer level front to rear when ready for the road, and you want at least 5" clearance between the top of the bedrails and the bottom of the 5er overhang.

Most pros say you need at least 6" clearance if you promise to never get off paved roads, and 8" clearance if you must tow on dirt roads. Make that 12" if you plan to tow on "off road" Jeep trails.

I had only 5" clearance between the top of my bed rails and the bottom of the trailer overhang, but I had big dents in the top of the bed rails to show for it.

Some will suggest you "flip the axles" on the trailer, but you don't literally turn over the axle. Instead you move the spring perches from under the axle to over the axle to gain about 4" of additional height. Then the trailer will look like it's wearing "high water pants" and the center of gravity is raised, but that's better than towing an unlevel trailer.

One help is to plan ahead and don't buy a 4x4 SRW "one ton" pickup to tow a 5er. The dually tow vehicles are usually lower to the ground than the SRW. And don't try to tell me that you cannot live without 4x4. I put over 100,000 miles on my 5er over 10 years with a 4x2 SRW pickup. Of course I on purpose stayed out of snow country in the wintertime.

[CoachCJ]

I have 6" clearance to the bed rail, about 5 1/2" to my cover rail. I have hit my cover rail one time with the pin box, just nicked it. I haven't had any close calls on pavement, but I park the trailer in my somewhat uneven yard, and I routinely travel to property that my family owns in Georgia which requires about a half mile of curvy hilly dirt road. I need every bit of that clearance, and yes I need 4 wheel drive. My hitch (B&W factory puck system) is at it's lowest, and the pin at it's lowest (longest distance from bottom of trailer to pin), the trailer is pretty darn level on my RAM dually 4x4 with this setup. My axles are already factory flipped on my toy hauler.

[JIMNLIN]

Advice? I've got it at a welder who wants to adjust the pin box height and then shave a little of the back end off. I have a feeling that idea is going to be heavily criticized...

Years back all 5th wheel pin boxes had square corners which made cutting clearance like biscuit shows in his picture a must for many truck/trailer combo's (mostely short bed trucks).
Listen to your welder

[jacknife]

Just remember that you don't want to get your fiver over 13,6.
M oryde 4000_will add an inch 285 tires should add about an inch. Putting 18 inch tires on your truck will also lower it . l also saw a truck with the bed sides custom lowered which looked pretty cool.

[SmokeyWren]

Originally Posted by Jacknife

l also saw a truck with the bed sides custom lowered which looked pretty cool.

And expensive.

One fix is to replace the pickup bed with a flat bed or a tow body. The least expensive Plain-Jane steel flat bed is only a few hundred bucks. Fancier flat beds with underside boxes and fancy headache racks can cost over $1,000 U.S. Be sure your flat bed has stake pockets all around, then you can add inexpensive sideboards and tailgate such as 2"x4" up to 2"x12" lumber for a few bucks to keep your stuff from rolling off the bed. Paint that lumber in your choice of color to make the flat bed look nice.
https://www.knapheide.com/gooseneck-bodies/pgna-p17

This image is a regular-cab Ram, but the bed will fit any pickup chassis that had a factory 8' bed so it has 56" or so CA (cab-to-axle distance). Flat beds to fit shorty pickups are also available from some manufacturers. You can't see the stake pockets in this bed, but they're there so it's easy to add sideboards and tailgate.



Or how about a fancy tow body, like this one?

Those nice sleek tow bodies can get way up there in cost in a hurry. A few years ago a Western Hauler tow body with all the toys was $6,750, so it's probably over $8,000 now. But it's a nice option to haul your too-low 5er with a too-high tow vehicle if you don't want a flatbed/stakebed.
Western Hauler - "The True Choice of Champions"

A compromise between a cheap flat bed and an expensive tow body is the Knapheide Westerner Storage Body. It's a service body with lots of storage boxes and low sides for hauling a trailer.


https://www.knapheide.com/gooseneck-...er-storage-p21

[chucksenough]

So we lowered the kingpin which looks like it helped a little with the bed cover clearance. I need a bigger open space to see if it's completely fixed but I still have some adjustments on the 5th wheel hitch if needed.

This said, I'm now more nose high as expected. Also, my axle springs have already been flipped on the trailer. Any good suggestions on how to measure the trailer height? Measure down from the side then add the front AC unit I guess?

So I need to get trailer axles up or truck down. I talked to my welder and he'd fabricate a lift kit for the trailer but he doesn't want to install it (liability). What about the truck? Can I put airbags on or something to help? Ideally, I could put some adjusting suspension back there as I'm using the truck as a daily driver and when empty, it's certainly a tight ride.

Perhaps reducing the block height on the rear of the truck between the axel and springs? I don't want to get the back too low because right now, when I connect to the trailer, my truck is pretty level (the kingpin is just over 2,000 lbs).

A lot of great suggestions already, of which I sincerely appreciate. Some creative ones as well, but I went 5'er because I wanted a pick-up and the F-350 PS King Ranch is quite nice.

[wingnut60]

Check with a competent spring/axle shop--they should be able to install the riser/spacer tubing easily, and do it right. I'm sure your welder would do it right also, but since he won't, then leave it to the pros.

[Wild Card]

You can also go to www.trailerblocks.com. they have lifting blocks...just like under your rear springs of the truck. Then add a product from Morryde called the x brace. You can get 3, one for each set of spring hangers if needed.

How unlevel is your tow? Rear most frame to forward most frame? 2" I wouldnt worry, 4" I would work on it.

[Hurk]

I have a 2014 Dodge Ram 3500 pulling a 2009 Cardinal 30 TS 34' the Cardinal has a long trail air pin box and with the TV being so high the Cardinal is off level and the pin box will hit TV box on tight turns. I had to raise Cardinal 5" with box suspension.(couldn't flip axels as already done at factory.

Got the Cardinal and hooked up the trailer is now level and the pin box is clear. I tested a 80deg turn and not a problem I will not hit the cab with the nose of the trailer or the pin box hitting rail.

The only issue is the step his up so I'll need another step. Might look at the new solid steps that flip up into rig but apparently they are quite dirty when flipped up into rig?