Weight distribution Hitch

[roaniecowpony]

As the second poster said, WD hitch will help to restore some of the weight back to the steering axle and some of the weight back to the trailer axle. This will level out your Jeep and help keep the axle and tire ratings within spec. These are more important than the hitch weight limitation of steps are taken to strengthen the hitch receiver.

In order to do this spring bars are used which apply a lot of torque to the receiver. This is the weak point in the system. It is not strong enough to resist this twisting moment.

I had a reputable hitch shop add some square steel tubing and a steel frame cross piece to add the needed strength. It works. I had them do this on my JKU and they bent the steel tubing around the muffler. To make a better job on my JLU I removed the muffler and added a small muffler behind the resonator and an an over the axle straight pipe. (Sounds great.)

Something kept me looking at these pictures. Aside from the workmanship of the welds, it appears to me the third picture shows a scabbed on tab welded to your body floor pan stiffener and attaching to the square tube and angle iron homemade crossmember. Then the last two pictures show welds attaching the homemade angle iron crossmember to the swaybar brackets. So, you have welded your body to your frame by way of these added parts. At least thats what I'm seeing in these pictures. You might want to get a second set of eyes on this from someone that is a qualified frame fabricator. This looks like a seriously poor design as well as poor execution. Keep in mind the body bolts to the frame with large rubber mounts to allow small movement and isolate vibration.

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[Drytellsr]

Something kept me looking at these pictures. Aside from the workmanship of the welds, it appears to me the third picture shows a scabbed on tab welded to your body floor pan stiffener and attaching to the square tube and angle iron homemade crossmember. Then the last two pictures show welds attaching the homemade angle iron crossmember to the swaybar brackets. So, you have welded your body to your frame by way of these added parts. At least thats what I'm seeing in these pictures. You might want to get a second set of eyes on this from someone that is a qualified frame fabricator. This looks like a seriously poor design as well as poor execution. Keep in mind the body bolts to the frame with large rubber mounts to allow small movement and isolate vibration.

I agree with you and I'll go all the way and say, "Those are crappy welds". I believe their are at least 3 forces that are at work in engineering and that would be Tension, Compression and Torque. When you weld something to a frame like that you are transferring those forces onto those welds, your not eliminating weight or the forces applied, your just distributing them. I'm sure it was your point to distribute the forces, but those welds are a huge concern. How will that set up hold up in a rear end collision? Will the cross member bow and damage your rear sway bar? will the welds snap? maybe creating more damage with than without.

 

[roaniecowpony]

I agree with you and I'll go all the way and say, "Those are crappy welds". I believe their are at least 3 forces that are at work in engineering and that would be Tension, Compression and Torque. When you weld something to a frame like that you are transferring those forces onto those welds, your not eliminating weight or the forces applied, your just distributing them. I'm sure it was your point to distribute the forces, but those welds are a huge concern. How will that set up hold up in a rear end collision? Will the cross member bow and damage your rear sway bar? will the welds snap? maybe creating more damage with than without.

I was onboard with the idea of the square tube extending forward off the hitch to transfer the torque load from the W/D hitch forward and into the frame. Those points forward of the hitch will have relatively low loads, probably in the hundreds of pounds. But the biggest faux pas, IMO, is the welding to the body floorpan stiffener, followed by welding to the swaybar brackets, rather than the frame rail. As bad as those welds are, they'd probably hold up to the light loads they see, if it weren't welded to both the body and frame. That's just bad.

 

[Canyonero JL]

The problem you’re going to run into with that camper is the frontal area. 32 sq-ft is the towing limit for JLU

The dimensions I can find on the Geo-pro 15TB are 9’7” tall and 7’4” wide... that’s 70 sq-ft.

Now I’m guessing the camper floor is maybe about a foot off the ground, but that would still put you at 63 sq-ft. I’d definitely do some in person measuring, but that looks way too big for a Wrangler.

Could you direct me to the Jeep operating instructions that provide for this? I can’t find any such restriction.

 

[SecondTJ]

Could you direct me to the Jeep operating instructions that provide for this? I can’t find any such restriction.

It’s in the owner’s manual.

32-sq-ft was for JKU (2-door JK was 25 sq-ft).

I mistakenly assumed it was the same for JL. Actually looks like towing was reduced on both 2-door & 4-door for JL. Down to 20 sq-ft and 30 sq-ft.

 

[Canyonero JL]

It’s in the owner’s manual.

32-sq-ft was for JKU (2-door JK was 25 sq-ft).

I mistakenly assumed it was the same for JL. Actually looks like towing was reduced on both 2-door & 4-door for JL. Down to 20 sq-ft and 30 sq-ft.

Thanks! Very interesting. I need to look into this. Seems odd, though, that a 2-door Jeep wouldn’t even be able to pull a Smittybilt Scout trailer, which was specifically designed for Jeeps. I calculate the frontal area of this trailer (without a rooftop tent) to be at about 25 square feet. With a standard rooftop tent, the frontal area would be over 30 square feet, more than what a 4-door Jeep can handle. I also own a 2013 Ford F 150 (V8 with tow package), and it has a 60 square foot frontal area limit. This area, however, excludes the tow vehicle’s frontal area (of about 35 square feet), which makes sense, because even with a frontal area limit of 60 square feet, you exceed even the smallest travel trailers‘ frontal areas.

 

[Canyonero JL]

It’s in the owner’s manual.

32-sq-ft was for JKU (2-door JK was 25 sq-ft).

I mistakenly assumed it was the same for JL. Actually looks like towing was reduced on both 2-door & 4-door for JL. Down to 20 sq-ft and 30 sq-ft.

See page 12 of Jeep’s own brochure. https://cdn.dealereprocess.org/cdn/brochures/jeep/ca/2020-wrangler.pdf
It shows a JLU towing a tall, very wide boat on a trailer with what appears to be two 3500lb axles. I can roughly calculate the frontal area of the boat to be at least 60 square feet, based on the fact that the boat sits much higher and wider than the Jeep. If 30 square feet is the true limit, isn’t the brochure a misrepresentation of Jeep’s towing capabilities?

 

[SecondTJ]

See page 12 of Jeep’s own brochure. https://cdn.dealereprocess.org/cdn/brochures/jeep/ca/2020-wrangler.pdf
It shows a JLU towing a tall, very wide boat on a trailer with what appears to be two 3500lb axles. I can roughly calculate the frontal area of the boat to be at least 60 square feet, based on the fact that the boat sits much higher and wider than the Jeep. If 30 square feet is the true limit, isn’t the brochure a misrepresentation of Jeep’s towing capabilities?

No, that doesn’t look like 60 sq-ft, boats are much easier to tow than campers. A travel trailer has significant aerodynamic drag plus 10-15% tongue weight.

I’ve seen some manufacturers hide in the fine print that their max towing capacity is only for a boat and towing other items reduces capacity

 

[Canyonero JL]

No, that doesn’t look like 60 sq-ft, boats are much easier to tow than campers. A travel trailer has significant aerodynamic drag plus 10-15% tongue weight.

I’ve seen some manufacturers hide in the fine print that their max towing capacity is only for a boat and towing other items reduces capacity

The boat sits at least one foot above the Jeep and at least two feet wider than the Jeep. I calculate at least 60 square feet.

 

[SecondTJ]

The boat sits at least one foot above the Jeep and at least two feet wider than the Jeep. I calculate at least 60 square feet.

It’s also 2 feet off the ground.... So going by your numbers it’s 5.15’ tall x 8.13’ wide = 41.8 sq-ft

Then factor in that the boat isn’t square and deduct this green area from the calculation.

Once you do that you’re close to the 30 sq-ft limit, maybe slightly over. Definitely not near 60 sq-ft

 

[Canyonero JL]

It’s also 2 feet off the ground.... So going by your numbers it’s 5.15’ tall x 8.13’ wide = 41.8 sq-ft

Then factor in that the boat isn’t square and deduct this green area from the calculation.

Once you do that you’re close to the 30 sq-ft limit, maybe slightly over. Definitely not near 60 sq-ft

Where does Jeep state that the frontal area limit is different for boats? This boat in the picture is nowhere close to having a 30 square-feet frontal area. How in good faith can you take that position? I’m curious, are you an employee/agent for FCA?

Again, I believe the boat is enormous. In fact, I submit that it has a frontal area much larger than many RVs. In my humble experience, I think it’s more difficult to tow something that has a large side surface area (like a boat) that is somewhat light, especially when being passed on the highway. If you’ve towed a variety of trailers, you know that trailer sway is much worse under these conditions. Personally, I’ve towed boats, rvs, and uhaul trailers.

If FCA doesn’t want Wrangler owners to tow, fine. FCA shouldn’t market the Wrangler as a tow vehicle (such as by selling a tow option and advertising it as such in their marketing materials). I think it’s misleading for FCA to do this while at the same time including a very low frontal area tow limit in the fine print of their digital-only owners’ manual. Did you notice that the brochure didn’t provide the frontal area limit? FCA shouldn’t hide this detail in the fine print.

If Jeep Cares is listening, I’d like to know the boat model and trailer name in the brochure, so that we can calculate the frontal area.

 

[Rubi II]

I am also currently looking for a travel trailer for my 2020 JLU and did some reading on the frontal area. I believe the frontal area is calculated by the amount of exposed area (from tow vehicle) of what you are towing.

 

[Pepe My Little Mule]

I am also currently looking for a travel trailer for my 2020 JLU and did some reading on the frontal area. I believe the frontal area is calculated by the amount of exposed area (from tow vehicle) of what you are towing.

I was also looking a that same camper, I like the features and construction...

To add even further question... export Wrangler JL's in Europe/Australia have a HIGHER tow rating than US spec'd models???

 

[roaniecowpony]

Frontal area, smontal area. I was an engineer at a large aircraft manufacturer. Not an aerodynamics engineer, but some has rubbed off on me over the decades. So you real aero engineers out there, feel free to correct me.

Frontal area is not equivalent to aerodynamic drag. Otherwise, streamlining a shape would be worthless. A trailer with flat front is not the same drag as an airstream front. A flat back of the trailer is not the same as an Airstream trailer or teardrop trailer. Also, a longer trailer has more drag than a shorter trailer. The efficiency of a shape is measured as coefficient of drag. A coefficient of 1.0 means the shape has a drag equivalent to a flat plate of the same frontal area. So, if you had a coefficient of drag of 1.0 and a frontal area 32 sq/ft, it'd have the same drag as 32 sq/ft of flat plate. A 2020 Corvette has a coefficient of something like 0.32 . So whatever the frontal area is (about 2.02 sq/meters for the C8 vette) is multiplied by the coefficient of drag and you get an approximation of the drag in flat plate area.

I stumbled on a RV forum that had a discussion that seemed to have some good info. https://www.fiberglassrv.com/forums/f56/trailer-frontal-area-77307.html

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