Teach me about pin boxes

[acdii]

I am reviewing several different trailers, up to 9 that have floorplans and weights that we can use. I see mentioned different times, Morryde pin boxes, or other types of pin boxes as upgrades.



So what are the differences? I have an F350 with the short bed, so want to make sure I get the correct type for clearance while turning. Some I see have some sort of cushioning built in, but there seemed to be a lot of emphasis on Morryde.

[dsol]

With a short bed you likely will need a slider hitch or a sidewinder. There are stories of standard hitches working in short boxes but since you need to buy one I would opt for the safer route.

Also the Mohr ride pins and others with the cushioning can have limited weight capacities so pay attention to the numbers and don’t forget to account for cargo capacity.

[acdii]

Truck came with a 5th already installed, but it is the type that has a slider attachment available for it.

[acdii]

We are down to two trailers now, an Arctic Wolf or a Keystone Sprinter. Put a down payment on the 3660 to hold it since its nearly $3K less than the 2021 model and don't want someone driving off with it before we have a chance to make the final decision.

Neither of these will clear the cab without help. Of all the sliders, the best one that allows for tight turns in all motions is the Demco. It would work for the Keystone since it has some corner setback, but I doubt it will work with the Arctic Wolf since the corners as pretty much in line with the Pinbox mount. The Demco allows for 14", and will work with almost any fifthwheel pinbox.

I just started viewing vids on the Sidewinder, and it allows for 22" clearance. It sounds like the proper thing to use for the two trailers I am looking at, but I am a bit concerned with stability. A standard pinbox is bolted securely to the frame, and the only loose point is the king pin itself. The 5th wheel is point where movement is allowed, fore-aft, left-right lean. With the Sidewinder though, in addition to the lean, it now has a second movement point, loosing a point of stability, so how does it impact the anti sway qualities the 5th wheel provides?

Price wise, the Sidewinder and the Demco are about the same, and since I already have a Q20, which is a good reliable Curt product, I am leaning towards the Sidewinder, only hesitation is the sway question.

[dsol]

Originally Posted by acdii

We are down to two trailers now, an Arctic Wolf or a Keystone Sprinter. Put a down payment on the 3660 to hold it since its nearly $3K less than the 2021 model and don't want someone driving off with it before we have a chance to make the final decision.

Neither of these will clear the cab without help. Of all the sliders, the best one that allows for tight turns in all motions is the Demco. It would work for the Keystone since it has some corner setback, but I doubt it will work with the Arctic Wolf since the corners as pretty much in line with the Pinbox mount. The Demco allows for 14", and will work with almost any fifthwheel pinbox.

I just started viewing vids on the Sidewinder, and it allows for 22" clearance. It sounds like the proper thing to use for the two trailers I am looking at, but I am a bit concerned with stability. A standard pinbox is bolted securely to the frame, and the only loose point is the king pin itself. The 5th wheel is point where movement is allowed, fore-aft, left-right lean. With the Sidewinder though, in addition to the lean, it now has a second movement point, loosing a point of stability, so how does it impact the anti sway qualities the 5th wheel provides?

Price wise, the Sidewinder and the Demco are about the same, and since I already have a Q20, which is a good reliable Curt product, I am leaning towards the Sidewinder, only hesitation is the sway question.

If you have the proper wedge for the sidewinder it locks in solid in the hitch. They come with a generic one but sell wedges for the specific fifth wheel hitch you have. You need that as it will not allow any rotation whatsoever at the hitch. Your hitch will still allow the side to side and up forward to back tilt but no more turning as that only happens at the turret which is now directly under the pin box instead of at the hitch.

I will tell you they are tricky to hitch to the truck with the specific wedge installed because it is like sliding a pizza with one piece missing back onto the removed piece by moving the pizza that is sitting in your truck bed but trust me it gets easier and easier each time and becomes a non-issue after a while.

But the hitch does need to be securely mounted in the bed because the sidewinder puts far more stress on the hitch mounting points than a traditional king pin does as it has 22” of “leverage” putting forces on the hitch. I am told goose-boxes and other hitches that sit in the bed but are not anchored at four corners will break or bend. I have the B&W companion and that is great.

Also, the pin box needs to have the turret torqued correctly so it doesn’t pivot too easily or stay locked straight. At the proper torque you will not be able to move the sidewinder at all by hand and only the weight of the trailer against the truck will move it.

3 or so years with this set up and very happy. The only known solution I could find with a Rambox truck that has a narrower bed than a traditional bed with open space above the wheel wells. I turn past 90 degrees on my culdesac and never been close to an impact.

And not having a slider means a fifth wheel that can be more easily removed from the bed as those sliders can weigh upwards of 200 pounds.

[acdii]

Thanks for the input, I am leaning more and more towards the Sidewinder. Difference in price for the standard, non air ride is on par with the Demco, so that is a non issue at this point. I found the Q20 wedge, but I would need to know the frame manufacturer for the correct swivel plate. The weight of it is the only problem, so will either have to have the trailer delivered here to install it myself since I can use my bucket loader to remove the old and install the new, or have the dealer install it and put my trust they know how to do it properly.

Wonder what the original pin box is worth.

The other questionable thing was sway, but after studying it, I can see it has built in sway control with the design. Going to put the Q20 back in the truck today to get some measurements to verify things, but pretty sure that I will go for the Sidewinder instead of replacing what I already have.

[dsol]

I think the key for sway is to make sure the turret bolts are torqued correctly. If lose there could be some serious sway. The instructions are pretty detailed on this process and they encourage pretty regular checks. Mine are always good when I check with the torque wrench.

[acdii]

Etrailer has a very good assembly video. The one thing that has changed since they created it is the wedge is no longer hammered in before torquing in place, instead they use a screw mechanism to tighten it, and suggest once it is tight to the 5th wheel to back the king pin out of the hitch and turn in in two more notches before securing the pin and then torque the bolts.

I just measured the clearance on my bed, 51 inches is the tightest to the cab, that is from the front of the kingpin to the cab above the rail, so add in the distance from the front of the king pin to the front of the trailer, which appears to be about 8", I should have measured since I had my tape measure in the truck, and if I set back 8" from the front of the king pin I have 58 inches clearance. The Dremco may have the clearance I need, but I need to get actual measurements first. When I measure 22" back, No clearance issues even with an ultra wide 101". One of the two I have in mind is an ultrawide.

Here's another thing I didn't consider. The weight! The kingpin box weighs about 200-250 pounds, same as the Reese, but the Dremco weighs an additional ~280 pounds, Compared to the Q20, it is a monster. The Q20 is only ~100 pounds, so, the Sidwinder is looking to be the only logical way to go. Whatever difference in weight between the fixed and sidewinder is minimal compared to swapping out the hitch itself.