What is the physical limitation of the JL's ability to tow?

[CounselorRedbeard]

In a nutshell, is the JL's towing limited by the brakes, or the gearing, or something else?

To elaborate, I keep eyeing the 2-door JL's towing capacity of 2,000 lbs across all trims. However, if you compare the 2017 JK, towing capacity varied based on the gear ratio, from 2,000 to 3,500. Other general research does indicate the rule of thumb is that towing capacity is dependent upon gear ratio, as well. This doesn't follow with the JL, however, since the Rubicon JL has a higher gear ratio than the Sport, but the same towing capacity; yet the 4-door boasts a 3,500 lb capacity with the same gearing, though I assume it has bigger brakes than the 2-door. I take it to mean that the JLs are limited by braking capability rather than pulling ability (i.e., gear ratio)...

My point of this pondering is to figure out whether re-gearing a 2-door to, say, a 4.88 ratio will improve the towing capacity from the measly 2,000 pounds the owner manual states. Of course, one has to consider the tire size in relation to the gears, etc. But, all things the same, does re-gearing increase your safe towing capacity on the JL, or do you need both lower gearing and bigger brakes to bump up that capacity, or is just brakes sufficient?

While I've seen some posts about people pulling 6,000 pound trailers with the 4-door, I haven't found anything breaking down the actual limitations and discussing what is the weak point.

To add an extra wrinkle, would an off road suspension throw the ability to tow heavy loads out the window completely?

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[displayname]

I believe the wheelbase handling the trailer at highway speeds is a significant factor for the 2 door vs 4 door tow limits.

 

[Carolina Jeeper]

Gear ratio is a major factor. The Rubicon has a lower gear ratio than a Sport, not higher. Also, the axles of a Rubicon are heavy duty in comparison to a Sport.
Without getting deep onto all of the variables that determine tow capacity, when Jeeps are equally powered, geared and equipped, the longer wheelbase 4 door is always going to be rated to tow more than shorter wheelbase 2 door Jeep.
I also know there's a way to determine maximum trailer length. The longer the wheelbase of the Jeep, the longer the trailer. It's independent of the tow capacity rating.

 

[wibornz]

Not advised, but my bud has been known to tow 13,000 pounds with his JLUR. I big Cat Skid steer with attachments and a steel trailer......

We give him a lot of shit over it because he owns four diesel trucks....... big diesel trucks...... like F650, F450......

 

[jeepingib]

It's the wheelbase that really limits the Wrangler. Especially the two door. It's very easy for a heavy trailer to have a "tail wagging the dog" scenario.

 

[MtCamper]

It's not really the go, it's the whoa. Low range, you can move most anything you can hook up to it. High range higher speed, can you stop it? Or rather I should say can you stop predictably within an acceptable distance. Remember when cars and trucks had nothing but mechanical drum brakes? They stopped, eventually. Well that's probably the same braking system on your towed unit, if it has brakes at all. As the weight of the towed approaches the tow, the tow brakes quickly become overwhelmed. That's the short explanation. The long one gets into level, distance of tow point to center of rear axle, weight and balance of load and a whole bunch of other stuff. I'm sure some complicated engineering is involved. My gut feeling is the manufacturers pulls a max number out of their collective butts that they figure they can justify in case of a lawsuit. Other than having to get a (deleted to not be political), it's still a free country, tow whatever you want. Just be ready to take personal responsibility for the result. BTW, the fifth wheel in my pic has disc brakes. The OEM drum ones were not up to the job.

 

[Herson]

What many people confuse about towing is that they think is all about horsepower and torque. The other factors that affect your towing capacity is cooling and brakes. You can have all the power to tow but if your cooling system is not built to handle the towing, your engine and transmission are going to overheat. Also the break system plays an important role in towing. That’s why the gladiator has bigger brakes than the JL.

 

[JeepinPete]

Do a search on J2807. That is the SAE standard that the auto manufacturers use these days to determine tow capacity. Once you understand how the testing is done, you can make your own judgement.

Pete

 

[cornercanyon]

Physics: All the horsepower, gearing, cooling (engine, transmission, tires, and brakes), braking, maintenance cannot overcome inertia. Think of all the different scenarios: speed, incline (up and down), relative lever arm length (length between nearest axle on each unit and hitch), weight, road condition, weather. The force (friction) applied between the tires and the road is limited whether you are stopping or starting. Essentially the greater the inertia and acceleration (or deceleration) required the lower the maximum tow capacity in relation to GCWR and GVWR on any given road surface.

Please be careful out there. Less is more—

 

[AcesandEights]

@JeepinPete nailed it.

It's about certification or meeting a standard, and whether a manufacturer needs or wants to have the vehicle certified to tow more. If Jeep wanted a 3,500 tow rating on the JL they'd run it through the paces, but Jeep doesn't market the vehicle as a tow vehicle, and they don't need to.

From the certification testing you can see what is important to get certified or meet the standard. From real world experience you can see what works and what doesn't. Regardless of certification, most people can agree the horsepower and torque of the JL will pull more weight. The brakes will stop more weight, but the way a Jeep handles makes it unsafe to pull/stop much more than 2,000 - 3,500 lbs. It'll do it, but can you do it in a straight line?

 

[jeepingib]

I see a lot of people mentioning that the Wrangler doesn't have brakes strong enough. But that is not the case at all. The brakes on a 2 door Rubicon are very similar to the brakes on the Gladiator. Yet the Gladiator is rated to tow around 4,000 lbs more. It's not because of the brakes. It is because of the wheelbase. When braking while cornering the 2dr will lose stability much faster when towing a heavy trailer. A longer, heavier vehicle is less susceptible to being pushed around by the mass of the trailer. This is why the manufacturer rates the 2 Dr lower. It can pull the same, and in perfect conditions can stop the load. But it cannot do it safely in all conditions.

 

[Turaven]

The wheelbase is the major limiting factor on the 2-door. You want as long a wheelbase as practical/possible for towing stability.

The second biggest factor is suspension setup, IMO. The Wrangler isn't setup to handle a high tongue weight, as towing is not it's primary mission by a longshot.

You could regear the Jeep, put in a heavy duty suspension, etc, and it will objectively tow the 2,000lbs limit better, but it won't raise the amount you can safely tow.

If you wanted to tow something 6,000lbs on a 2-door on private property at like 5mph then go for it. The low stability and safety risk kicks in at highway speed with innocent bystanders. You'd need to distribute the trailer weight very poorly or look like a rocket ship ready for takeoff.

 

[Zandcwhite]

It's not a physical limitation at all. Our 01 grand Cherokee was rated to tow 5k lbs. Our jlur has a longer wheelbase, more weight, better cooling, more power, stronger axles, and a full frame vs a unibody. It's a better tow vehicle in every measurable way. It is simply the rating jeep bothered to certify them at. The short wheelbase of the JL can get sketchy when towing as the front end gets very light.

 

[Bob_N_AZ]

It's not really the go, it's the whoa. Low range, you can move most anything you can hook up to it. High range higher speed, can you stop it? Or rather I should say can you stop predictably within an acceptable distance. Remember when cars and trucks had nothing but mechanical drum brakes? They stopped, eventually. Well that's probably the same braking system on your towed unit, if it has brakes at all. As the weight of the towed approaches the tow, the tow brakes quickly become overwhelmed. That's the short explanation. The long one gets into level, distance of tow point to center of rear axle, weight and balance of load and a whole bunch of other stuff. I'm sure some complicated engineering is involved. My gut feeling is the manufacturers pulls a max number out of their collective butts that they figure they can justify in case of a lawsuit. Other than having to get a (deleted to not be political), it's still a free country, tow whatever you want. Just be ready to take personal responsibility for the result. BTW, the fifth wheel in my pic has disc brakes. The OEM drum ones were not up to the job.

Disc brakes on a 5th wheel, sweet. It probably wasn't cheep but worked a lot better. If I ever get another 5th I'll put disc brakes on.

 

[Viking Jeeper]

The manufacturer will probably never reveal the limitation for liability purposes but I believe ALL unlimited Wranglers have been 3.5 and all non unlimited have been 2.0. My 2006 unlimited 2 door has a towing capacity of 3.5K even with the relatively weak brakes and engine.

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