What is the JL Pulling Capacity? (Recovery, Not Towing)

[Flip]

Just curious:

I know there are lots of different types of recovery situations but wouldn't using the winch be safer than using the transmission?

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[USNvet]

A situation arose which made me wonder exactly what the JL pulling capacity is. I'm not talking about towing. That's well documented. I'm talking about recovery capacity. As in dropping into 4WD LOW with F&R lockers and pulling all you can. It occurred to me during this recovery that I don't really know how much force my Jeep could potentially exert and if I could possibly exceed the working load limit of the recovery points/shackle/snatch strap or chain.

Yes, I'm a geek and like to do the math. Especially when failure could mean a shackle rocketing into your head. This isn't the kind of "hold my beer" moment I want to go out in.

As you can see the recovery from the muddy wash was successful. Obviously it will depend upon how much purchase you can get on the terrain. Looking at the footage I'm actually torqueing my tires slightly so it must be a sizable amount of force. But how much force could it potentially be? IDK.

Does anyone know if someone has hooked a JL to an immovable object, pulled and measured the load force on the chain or strap? What amount of force could I be wielding here?

In this situation we opted for chain as there were horses in the trailer. Didn't want to jerk them too much with a snatch strap. If chain failed we'd unload the horses. If still stuck we'd bring out the snatch strap and give it a good yank. But chains worked.

You live in Utah. Pay Mike Patey's shop a visit. Maybe he'll let you hook up to his strain gauge! Skip ahead to around minute 18 for a demo:

 

[Reinen]

You live in Utah. Pay Mike Patey's shop a visit. Maybe he'll let you hook up to his strain gauge! Skip ahead to around minute 18 for a demo:

That's exactly what I want to do!
One pull on pavement, one on dirt and just because it's awesome, see how the JL compares to that truck getting pulled by the plane since I can lock all 4 tires. Half that truck's weight is free rolling after all.

 

[azwjowner]

Thats why I'm looking for a reasonably ballpark number. I don't like unknowns.

I don't want to estimate low and snap any equipment.
I don't want to estimate high because it might be a waste of time to even attempt as I can't pull as hard as I think.

I'm surprised that I still haven't found a ballpark figure of what kind of pulling force a JL can produce. No wonder recovery accidents happen. I can't get figures to pick the right tool for the job.

Please end the debate in the thread. Buy this 2200 pound crane gauge: https://www.amazon.com/dp/B0C3RTXY2...ms&th=1#aw-udpv3-customer-reviews_feature_div

With snatch blocks in the opposite configuration of normal you can reduce the pulling force to within the 2200 pound scale rating. You'll have to account for friction but it'll be close enough.

 

[tk1700]

I think you're making my point. The approximate amount of force that will be required to recover this vehicle can be calculated. It will require somewhere in the neighborhood of an 8,438 lb pull, based on the assumption that the passenger tires are equally as buried as the driver tires and the vehicle weighs 4,500 lbs.

Now if I know my Jeep won't be able to pull that much (which I suspect it won't) then I wouldn't waste my time attempting a tow line. I might be able to inch it out using momentum but that would certainly be required, it's more dangerous and it would be slow progress. High risk for low reward, not worth attempting.

For this I'd go directly to winch, using a double-line pull because I don't like going over 80% of my winch capacity unless there is no other option.

I disagree that it can be calculated. You are making assumptions. It's easy to guess an approximate weight of the truck. The big unknowns that can't be calculated are how much mud is caked in the under carriage, how much mud will the truck be pushing as it moves forward, what effect will suction have on the truck and how much help will the truck provide if it's being driven during the recovery?

 

[Reinen]

I disagree that it can be calculated. You are making assumptions. It's easy to guess an approximate weight of the truck. The big unknowns that can't be calculated are how much mud is caked in the under carriage, how much mud will the truck be pushing as it moves forward, what effect will suction have on the truck and how much help will the truck provide if it's being driven during the recovery?

All of those things are parameters of the calculation. It is of course ballpark but it gives you a reasonably good idea of what you're in for. The calculations were enough to make it clear your initial tow strap approach would fail and it was risk for no reward.

 

[Reinen]

Please end the debate in the thread. Buy this 2200 pound crane gauge: https://www.amazon.com/dp/B0C3RTXY2...ms&th=1#aw-udpv3-customer-reviews_feature_div

With snatch blocks in the opposite configuration of normal you can reduce the pulling force to within the 2200 pound scale rating. You'll have to account for friction but it'll be close enough.

Oooh, that is a reasonable option isn't it.

I don't think I'd even need to account for friction if I attach to an immoveable object. Nothing will be sliding to create friction once the pulling force is balanced.

Thanks, I'll seriously consider that!

 

[azwjowner]

Oooh, that is a reasonable option isn't it.

I don't think I'd even need to account for friction if I attach to an immoveable object. Nothing will be sliding to create friction once the pulling force is balanced.

Thanks, I'll seriously consider that!

If I'm thinking about the problem properly, I think you would simply swap the Jeep and the tree in the usual double or triple line configurations, and put the scale on one of the multiple lines that now would attach to the tree instead of the Jeep:

 

[Reinen]

If I'm thinking about the problem properly, I think you would simply swap the Jeep and the tree in the usual double or triple line configurations, and put the scale on one of the multiple lines that now would attach to the tree instead of the Jeep:

Actually you'd just spin the Jeep around and pull instead of using the winch. The load will be evenly distributed among each of the 1, 2 or 3 lines. Scale goes on the termination point of the line.

 

[azwjowner]

Actually you'd just spin the Jeep around and pull instead of using the winch. The load will be evenly distributed among each of the 1, 2 or 3 lines. Scale goes on the termination point of the line.

True. That's simpler.

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