2021 Ford Bronco's crawler gear fills off-road demands, here's why
Choose the Bronco's manual transmission and you'll notice a "C" on the stick -- it unlocks a special tool to keep your clutch happy.
We'd heard Ford planned a seven-speed manual transmission for the 2021 Bronco for a long time. Seriously, the rumors date back a couple of years. However, it's not a seven-speed manual in the traditional sense. No, instead, it's a six-speed with a dedicated crawler gear.
You've definitely read about this crawler gear by now if you're at least remotely interested in the off-road SUV, but perhaps you don't know exactly what it does, or why it's so important. Don't fret because explainer extraordinaire Jason Fenske of Engineering Explained has you covered in a video posted July 22 (see above). He's the man who can really help even us here at Roadshow make sense of the numbers and math involved and we're grateful for it.
Essentially, the crawler gear is like first gear with a higher gear ratio, which provides more wheel torque, but lower speed at the same time. What's good to do at lower speeds with higher amounts of torque? Off-roading. You probably see where this is headed.
Power from the 2.3-liter turbo-four engine flows to the transmission. As it flows, wheel torque multiplies by the ratios. In the crawler gear's case, it's 6.588. The next stop is the transfer case, and in low with the highest gear ratio case offered, wheel torque multiplies again by 3.06. Finally, the rear differential multiplies wheel torque once more by 4.7. This gear ratio explainer showcases why the gear ratios are important because it shows there's approximately 40,000 pound-feet of wheel torque the Bronco can lay down. Though it's definitely not all available since tires can only take so much before spinning. Also: Wheel torque is not the same as engine torque, so this isn't totally the point of the crawler gear.
You know if you've driven a car with a manual transmission that you can't just let the clutch out when you want to. You have to reach a certain speed where the transmission's happy. When off-roading, it's important to take things slow so drivers can maneuver correctly. All the while, it's not good to keep slipping the clutch and wearing it more than it needs to be. This is the point: The crawler gear gives you a single gear to basically go about your business in without even thinking about touching the clutch pedal. There's full control of the Bronco at incredibly low speeds.
Fenske uses a great example of traveling at 1,000 rpm in the Bronco. Considering everything mentioned above, 1,000 rpm in the SUV's crawler gear likely means the driver's going about 1 mph. Estimating the Bronco's redline somewhere around 6,500 rpm, that means drivers will likely be able to go almost 7 mph in the crawler gear and not have to worry about feathering the clutch.
That, friends, makes off-roading a whole lot easier.
