How The 2021 Ford Bronco's Clever Crawler Gear Works
Motor
2021 Ford Bronco Has A Manual Transmission With A Crawler Gear!
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The 2021 Ford Bronco has won over the hearts of both off-road enthusiasts and mall-crawlers alike. It's a genuinely beautiful blend of both on-road and off-road usability. The Ford Bronco has two engine options, a 2.3L turbocharged four-cylinder or a 2.7L twin-turbo V6. If you choose the inline-four, you'll be rewarded with the option of a manual transmission. Not just a six-speed, it also offers a crawler gear! You'll find a "C" labeled on the stick shift. In this video, we'll learn about what crawler gears are, why they're implemented, and when they're useful. It all leads to the Ford Bronco's bonkers 94.75 crawl ratio! We'll be talking wheel torque, wheel forces, and wheel speeds - hope you enjoy!
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Kommentarer
*COMMON QUESTION:* Many comments confused about section 3, wheel force. Folks wondering why aren't you multiplying the 5,000 by 4 since there are 4 tires. As mentioned, I'm modeling it as *all* of the weight on a *single* tire. If you were to look at individual tires (assuming equal weight distribution), each tire can put down a max of 1250 lbf (5000 lbf / 4 tires). Add up the tires, model it as a single tire, and you get 5000 lbf. This number is far, far less than 21000 lbf.
Mac Gyver
4 måneder siden
they will limit the torque, but no because of tyre slipping but because of axles. If you engage all difflocks, then theoritically you can have all the torque at only one half-shaft. There is no cv joint which could survive this
Si Raff
5 måneder siden
With a full load and sticky tyres you could probably get it up around 7000-8000lbs max. Even at half its peak torque that would still be far too much - but that is at peak. I hope they flatten the curve and allow equivalent to say 10,000lbs wheel force but have most or all of that available over as much of the rpm range as possible. We also have to remember there is a good chance of people fitting larger tyres which will reduce the effect somewhat so having a decent buffer would be nice. Either way its nice to see them actualyl putting this stuff in a vehicle. I would much rather see diverse vehicles than one box fits all.
spider live
5 måneder siden
The tires diameter won't change even with more tires!
Alex Desmond
5 måneder siden
I've worked on a similar project to this for a truck manufacturer. Interesting video. There's a couple of things you have missed. Yes the engine torque is often limited in lower gears (Even in high range in some cases) however the reason it's limited is component protection not tyre grip. You can put much higher greater torque than you calculated through tyre's in certain scenarios for short periods of time. If you try to put 20,000nm+ to one wheel you will however snap a drive Shaft or half shaft. To make them strong enough they would be too heavy. Second point you need very high torque for split mu boulder crawling. The scenario is one or more wheel's is not touching the ground. You are stationary. And you need to climb a boulder to move forwards. You need 12,000nm + available to one wheel to achieve this in a 2 tonne car for very short periods of time. To achieve this you need a system capable of doing 40,000nm to four wheels because of limitations in differentials in terms of how you can split torque. I know because we tested it, third point system losses. Because of losses you end up loosing a significant chunk of your torque through your drivetrain. So a theoretical 40,000nm split between all four wheels is not crazy in a propper off roader, Another point is actually wheel torque is really a good way of looking at things. The issue with Tesla is comparing wheel torque to motor torque confuses things. Another point. A clutch is actually a torque multiplying device. If you slip your clutch you increase your effective ratio so you can get even more torque. Funnily enough most standard manual cars can do around 10,000nm total wheel torque because this is what you need to do a extreme hill start, but you have to slip the clutch a lot and therefore it's at a very low speed for a short duration. Torque doesn't tell you anything about a car's performance unless the context is determined.
John Doe
6 måneder siden
@Daver G How did that work as a daily driver? 😄 Seriously, though, what kind of terrain requires 1 inch per second speeds? Seems like something only a small number of should-buy-a-Unimog-instead buyers would need. 😄
Geared for crawling, but then they put independent front suspension. Must be a mall crawler. 🤣
Ford is flooring it in there videos
Your tesla cybertruck drawing was better, because that was actually blueprints to the design
This video is amazing. Thank you for breaking it down. I was wondering how all these numbers would actually translate into speeds. To me, crawler gear= really slow speed but had no idea how to break those ratios down. Great vid, smart dude lol.
Amazing way of laying it out. Always come by and learn good useful information. 🙏
So wait, just so I understand. It’s basically one single gear out of a traditional low range gear box that many 4x4’s have, that simply has an extremely low gear ratio but compared to a LR gear box cannot be used in conjunction with all the other gears? So instead of being able to drive in L-1/2/3/4/5 OR H-1/2/3/4/5; with the bronco you can only select C/1/2/3/4/5/6. But with “C” you’re likely able to crawl slower than wirh L-1 in many other vehicles?
Hey, Jason. Great channel. But you’re clearly not an Off Road guy. To figure out the maximum power possible in a vehicle like this, you have to consider weight transfer in off road conditions even to a single wheel, short term increase in grip on small rocks etc. You’re using measurements for road vehicles that make no sense for off road vehicles. Surely the limit of the power possible to put down is most likely where components break due to the torque. Let’s see you develop some math for off road before you take down crawler gears :-)
I drove my 99 Tacoma the way Ford drives in their pr off road footage for 11 years n shes still running. How long can u drive the bronco that way?
This makes me want one even more. I cannot even come close to crawling my Tacoma in 4Lo.
for off-road tires it sometimes makes sense to spin tires (a little) to get better acceleration or greater towing force etc. rough tire digs itself in ground and gets virtually higher friction coefficient (or something like that). anyway max wheel torque is still too high.
So tldr its a Low gear with marketeering wank.
Would be great for driving thru Central London, especially trying to pull out of their tight parking spots
Even though the torque of that crawl ratio greatly exceeds the grip the tires are capable of, you wouldn't necessarily want to limit the torque. When you're driving off road, a lot of the time you accept that your tires will more than likely have some degree of slippage. If you're crawling on rocks for example, you may want the tires to be able to slip so they can heat up a little bit, and/or move them around in order to "find grip". If you watch some of the Marlin Crawler demonstrational videos you can see how this works, its pretty cool. Those guys have built trucks with crawl ratios over 500:1
He made my head hurt. Wonder if this is on a spread sheet to play with... different tire sizes, different ring and pinion ratios, etc. Maybe then I'l get it... (you know, he could be just making all this up and most of us won't know it.) ;)
I hope I don't need a physics degree to figure out if I should order the advanced auto transferase case with the manual or will lockers and the standard part time selectable be enough. I still have to drive this most of the time on the street.
Using CVT transmission not sufficient to put up with stress from high torque?
You do an awesome job!
The Bronco 3 door badlands with a manual transmission is the rig I'm waiting for.
Mate I just love your videos, informative is understatement.
Ford Execs: So what do you call this shade of orange? Marketing: OJ
I was gonna complain that Crawler gear is useless, as 1st gear in Low can still put out 15,272 lbf, way more than the car can put down. BUT I see it's all about SPEED.
I like engineering explained videos, but I find everything a little hard to understand at times, if you know what I mean.
can’t wait to see people blow out their transmission with shifting into the crawl gear at highway speeds
"Let's model the whole car as one giant wheel" Oh no, he's turning into a physicist
So why do they only offer a MT with the least powerful engine in every car?
Soooo, How many times did he use the word Torque in this video??
Now I want one
0:13 What is that C4? I see what you did there. 👀
Warning Freedom Units to follow 😂
Great work on explaining this. EE .nice done by Ford.
1st low < crawler gear operation enables operators to travel clutch disengaged more often.
0:13 people who are in a bank and look at the vault
9:15 Yup, you sure are an awesome drawler
So let me get this straight, The tire rotates slower in a lower gear and produces higher torque...right? Mission accomplished!
I was waiting for 'granny' gear. Freedom units for the win? Haha Metric is so much easier to look at, but this is 'Murica!
Superb, well presented 🙏🏼
Euclid here! Just thought I'd chime in from 400 bc and ask if this hunk of junk can support its own weight? Thanks!
My dads old gmc has a "granny low" gear, sometimes i forget its not 1st gear & i swear that thing could climb a mountain in that gear.
0:14 well, it’s not for explosives, I’ll tell you that much.. heh
But what about a reverse gear ratio? Backwards crawling is also very usable feature. They should just include their super low range to the transfer box.
BRANDNAME PRINTED OVER THE WIDTH OF THE GRILL=DYSGENICS IS REAL.
21,000 divided by 4 wheels is dam close to that 5000lbs each tire can grab....... Jus sayin
Good job
What's C-4... hopefully not another Exploder (Explorer)
Great. Now do the math on the 10 speed. Thanks
every gear and every joint gets that amount of torque in the drive line 29,000 ft./lbs can break axles u joints and drive shafts. in my 78 with crawler and low transfer gear I've seen that twist my suspension driving a 0 slip setup.
2:31 The crawler gear ratio isn't really that high, when you think the Bronco has 35" tires. That means it does about 12,5MPH at ~1000RPM idle speed, which is about the same as most cars would do at 1000RPM. It's like the crawler gear, just offsets the large tire diameter.
VERY GOOD INFO.
"Change is scary, so we're going to continue using slugs and marbles and whatever else is nearby as our primary units" too good.
Delibro
5 måneder siden
Ah yes, I loved that too. Never liked someone using imperial units more :D
I saw three of them on the road last weekend. Ford does a lot of hard road testing up here in Colorado
Doing that same math (yeah, I'm a nerd too, I have rough numbers available just because) my 74 Comet was around 2,000 ft lbs of torque in first, your average Fox body Mustang 5.0 is 2,700 ft lbs in first. My 74 F100 with a 390 is 3,200 ft lbs. My punk ass 1998 Ford Ranger with a 3.0 v6, 150 hp, 150 ft lbs of torque, is nearly 6,000 ft lbs in 4WD Low. 29,000 ft lbs of torque is crazy. That's far more than the truck can actually use. It's all about traction.
Absolutely love your enthusiasm when concluding the 1mph haha. Really love your content!
👍👌
What is the difference between this ford system and crawl control that comes in land cruiser? Thanks.
The higher the gear ration number the lower the actual gearing is. Hence why 4 high is 1:1 and 4 low is usually 2.72:1 in modern production vehicles.
Since engine torque isn't the limiting factor, if we apply this to the A10 transmission, would there be any difference in wheel torque between the 2.3 and the 2.7 engines?
I don't know if front CV joints can handle all this torque. Coming soon the Rubicon trail gonna answer this question
why aren't many Full EV/Hybrid offroaders out there, since electric motor could deliver peak torque starting from 0 RPM (and torque matters a lot for offroader)?
Wish I could afford one when it's available.
Could you please explain more, I get confused about your calculations! First I think the wheel speed value is covered by second Newton law, £torques=jdw/dt, where is the car torque load!, in your example if we assume that you've worked with a real value of Bronco car, the sixeth gear ratio (0.646) will get almost just 156km/h of the wheel speed when the engine run at it's preferable speed 3000rpm ! (Wheel of 33" of diameter) (3000/3)*3.14*0.83*0.06=156 km/h.
Quick side note, does anyone know if Ford will be producing the Bronco in white for this run? That'll bring up some bad memories for some people.
same idea as the old granny low 4 spd they had back in the day in ford trucks with more high gears
i fine that when using imperial.standard measure .metric always finds it way way wedged in there somewhere, and wiseawersa
I wonder when we'll see he first CVT in an off-road SUV or truck.
El Ectric
2 måneder siden
PLEASE don't give them ideas lmao
DårK Šøûł
5 måneder siden
Lol
What the heck is pound force? I only speak Newton.
@10:33 After all that confusing math ONE
Very good explanation, I felt at a classroom!
This man makes me respect mathematics and physics!!!
I have been looking over the comparison chart provided by Ford and the Outer Banks trim level is standard with the 2.3L and the 10 speed automatic transmission! The Base, Big Bend, Black Diamond and Badlands all come standard with the 2.3l and 7 Speed manual transmission. 2.7L is an option in all trim levels except the Wild Trak and the First Edition here the 2.7L is standard as is the 10 speed Automatic Transmission. So, knowing this it would be possible to keep the 2.3L and opt for the 10 speed automatic in your build out! Time will tell if this is correct.
This was an awesome video to watch about gearing in general. And EE makes it all the lot more enjoyable and instructive as usual 😊👌
Thank you!!!!!
Something else that a lot of people very easily overlook is stall torque. The engine in my Jeep is known to be very 'torquey', even though the peak torque numbers aren't really all that impressive. It makes less peak torque than the engine that replaced it. But if you put the pentastar and the 4.0 infront of identical gearing (trans, transfer case, rear end) + equally sized tires, the 4.0 will win tug-o-war when they're both idling. It's a (nearly) square engine with a much larger, heavier crank; much more momentum when it's moving (as opposed to the much lighter bottom end of the 3.6). This is why. The same thing can be said about a 12v cummins- 400 ft-lb doesn't sound like much, but it makes that torque so effortlessly. It feels the same pulling a trailer up a hill as it does pulling out of a driveway. Power is what you brag about, torque is what you feel... I cannot fathom why stall torque isn't a metric that OEMs use for marketing heavy trucks and 'off road vehicles'. At least for now, Ford isn't offering these with any larger displacement engines. Gearing is an easy way to compensate for that, good on them for that.
Actually , torque is radius x force, not force x radius.. For a scalar equation it makes no difference, while for the vector multiplication, the output vector ill result in an opposite direction than actual.
I want a yellow 2-door with port-hole doors !
516+ Tesla fans realized that there are no electric vehicle chargers along real "badlands" off road driving locations in the world.
Freedumb Units? LOL truly funny. Go Metric my friend it’s much easier and it will free your mind! Also, after watching the videos of the Bronco nose diving and bouncing across the plains I am not sure the suspension they are making is up to the job of taming that wild horse. There seems to be a general lack of damping for such a short wheelbase.
It's like Dodge ram Cummins first gear.
Freedom Units.... thanks for that. In a more and more dark world little things like those comments and your very easy to understand enginerding videos are AWESOME
I wonder if they offer a V8 in a few years. Kind of similar to hide originally came out there was a 6 first and then an eighth later.
0:36 METH
More interesting would be, what is the torque at 1000 - 2000 or so RPM? Since this is NOT electric, full torque will only be available at a much higher RPM. Without access to the torque curve chart, we can't calculate this number...
I can wait for people trying to launch hard with crawl gear.
Finally, a car for Indian roads...
Are those Aluminum A-Arms on the front end?
Crawler is what gears are imaginary things that are invented when marketing departments are presented with Granny gears.
How do cars dynamically change tire pressure? I spent a whole 16 seconds googling and all I got was super detailed research papers when this is the one time I really just wanted yahoo answers. Is there a hose connecting the tire to the car? Or is it built into the rim and electronic?
Is 1000 rpm actually the lowest it can go though? I mean it's a pretty big engine.
Gavin Barker
5 måneder siden
@junoguten true, you'd be able to fall off of the clutch and it probably wouldn't stall. Tractors have had them forever, you just set them off then hop out and throw hay off of the back or whatever (though some have a hand throttle too, which means you can set the throttle above idle)
junoguten
5 måneder siden
Yeah but I mean in the crawl gear it probably doesn't need that much engine torque. The "it's a pretty big engine"-part is cause engines with longer lift on the crankshaft tend to be lower-revving.
Gavin Barker
5 måneder siden
The thing is that at 1000rpm it has a fraction of the power and torque of the engine
I was going to say that the acceleration in the crawler gear would be really high but I can imagine it's limited by the spool up time on the engine plus I can imagine if you just floored it it would just spin the wheels before getting upto a very low top speed at max rpm
Regarding wheel force, if the rear tires are pushing the fronts into a ledge the friction coefficient will be greatly increased and the extra force can actually be used. Some off-road situations really bind up the drive line as well, such as turning full lock with diffs locked. The tires will all try to spin at the same speed while moving in different arcs, and they will skid. Combine this with aired-down tires on grippy rock and you can use way more than that theoretical 5,000 pound-force figure. Deep lugs on mud-terrain tires really grip in small sharp features on rocks too.
Some reason the new Bronco looks like a redesign FJ.
The crawler gear definitely is t being used in the one bouncing and lurching over rocks. U
6.588:1 is lower than 4.283:1, not higher.
It was built on the same platform as a ford ranger, it’s not going to be anything insane. I just hope they make it durable
so... because, math. I almost understood all of that, so you did an awesome job, as always :)
Jason, we all know you hire a grad student as an EE apprentice to produce those flashy technical whiteboard sketches. I mean just look at that detail! The perfectly chosen exact hue of "Cyber Orange" for the door panels and they even included those black trail sights on the hood. Simply amazing, give them an extra gold star from me....and tell them to hurry up with your iced Ristretto 10 shot venti 5 pump vanilla 7 pump caramel 4 Splenda poured and not shaken starbucks order! Daddy ain't getting out of bed to shoot without his morning caffeine ritual first
Is it just me or does this guy seem salty because freedom units are better. Most higher forms of math use the imperial system for accuracy. I do under stand lower educated people using metric but why should any school system assume you want to be under educated. Can't wait to get all the cringeworthy responses from people who don't know better.
So what do you think the Wrangler has to do engineer wise to surpass Fords engineering in the Bronc0. This pissing contest is going to be fun.
I'll probably never go off-road but I want a Bronco now.
Cool, in short, the new Jeep Wrangler, the new Land Rover Defender and the Cybertruck are toast.