Two Trailers, One WDH?

[PineKnot]

I have a 16' enclosed (GW 7000) and a 20' car hauler type flatbed equipment (GW 12000), both dual axle with all axle brakes.
I have to tow each with sig truck (which has all factory trailer tow options) long distances on every road type. I have towed the 20 footer at nearly full load without handling issues, but I want to be safe so I'm inclined to get the right WD hitch for it before I do more.
Question is, should I or can I use the same hitch setup for the enclosed van at partial to full load, or do I need nothing at all, or a different setup for it?
Trying to end up with the right rig(s) without duplication or unecessary expense.

[NYB]

Consider getting the Reese High Performance Straight Line Dual Cam WDH system.

1. The hitch head that receives the trunion bars is the same, so no duplication there

2. Assuming the ball coupler for both your trailers is 2 5/16th , just one ball is needed on your one head, so no duplication there.

3. The stinger (adjustable hitch bar) is height adjustable, so even if the trailer coupler heights differ between the trailers, you can undo the two bolts through the stinger and reset the hitch head to the height of the other trailer, so no duplication there.

4. For the 12K lb trailer, get a pair of 1,700 lb spring bars.

5. For the 7k lb trailer, get a pair of 1,200 lb spring bars.

Note: both 4 & 5 assume a tongue weight greater than 10% of trailers GVWR. The recommended range of tongue weight on bumper pulls is from 10 to 15%, and 1,700 lb bars is 14% of 12K lbs, while 1,200 lb bars are a little stiff at 17%... however, on my 16' enclosed tandem axle cargo trailer, I find it hard to load without incroaching on 1,200 lbs tongue weight, despite the trailer weight being below the 7,700 lb GVWR. And I don't guess or estimate tongue weight. I physically weight it, at each and every load change, with a Sherline tongue weight scale made for this purpose. I do the same for my 24' enclosed tandem trailer, and find that it can easily weigh 1,600 lbs on the tongue even when I think I've balanced the load. So consider getting a tongue weight scale, cause I'd never check this all important data nearly as often if I had to deal with a bathroom scale, a board, and a brick.

The next size down on Trunnion style bars is 800 lbs, and they may not be good enough for your 7K lb trailer for a few reasons. First, at the proposed GVWR, the 800 lb bars are too near their rated capacity. Second, a customer service rep from Reese once reported that the steel used for the 800 lb bars is lesser grade than that of the 1200 and 1700 lb bars. Third, the bar stock diameter on the 800 lb bars is the same as is on the 600 lb bars. Fourth, the 800 lb bars use a smaller trunnion casting, whereas the trunions on the 1,200 and 1,700 lb bars are interchangeable.

One can also get 1,000 lb bars, which would also work for your smaller trailer, but that would be in a different bar style... the round bar, which is not compatible with the hitch head you would need for your larger trailer, that uses trunion style bars. So that brings us back to reaffirming two pairs of bars that interchange with one hitch head... the 1,200 and 1,700 lb. bars.

6. Instead of two snap up frame brackets for the tensioning chains, you'll need 4. These can be permanently mounted on the A Frame of each trailer.

7. Instead of two frame brackets for the Dual cam Sway arms, you'll need 4. More correctly, you'll need two right hand and two left hand. These can be mounted permanently to the A frames of each of your trailers.

8. Cam Arm Assemblies... you can get away with just one pair of these, and transfer them back and forth between trailers, since the frame brackets are already there, per item 7.

So, theoretically, if both trailers were more or less the same height, you would only have to pull your cam arms, one bolt each, and walk back and forth from trailer to trailer, since you already have the cheapest parts (the frame brackets noted in items 6 and 7) duplicated and installed. The most expensive parts, ie, the stinger, the hitch head, and the cam arms, transfer back and forth. The spring bars are only different because of the weight difference between trailers, and in fact the 1,200 lb bars could be used on the 12K lb trailer when it is loaded light.

So goes the theory.

The PRACTICE is yet another matter. Because in practice, it takes a fair amount of time to properly dial in a WDH system, of any kind, and the key factors that make the difference in a safe, sway free tow, and a white knuckle wrangling, are those little adjustments made to the hitch head angle, the length of the the cam arms, and the number of links on the chain.

While the chain is easy, the serrated washer settings that control the hitch head angle are more time consuming to set, and those bolts have a fairly high torque specification (300 ft lbs). Then the cam arm length is set by two nuts postioned on either side of a threaded shaft, and it takes more fiddle time to loosen, move, tighten, check, repeat.

So even while near lack of duplication is achieveable monetarily, the cost in time when transferring the set up may not be worth the couple more hundred it might cost to duplicate a WDH hitch set up and keep it dialed in for each trailer weight and tongue height.

You may not need a WDH set up at all for your 7K trailer, depending on your factory hitch platform (Ford offered different options in 2005), but most truck and trailer mfrs recommend one for any trailer above 5,000 GVWR.

I've been down the same road with two different sized trailers, so I'm sharing my experiences. Hope it helps as you consider what to do.

[PineKnot]

Wow! Thank you for taking the time for such a detailed and comprehensive explanation. You have removed some confusion and answered my questions, even anticipating one I didn't ask about the Sherline tongue scale. That will be important because I'll never have the same load twice.
Much here to digest and consider, but the right mix is in there. Thanks!