Bronco’s rumored seven-speed manual could include low-speed crawler gear
A new document from Getrag lends credence to the rumor that the 2021 Ford Bronco will be available with a seven-speed manual transmission with a “crawler” gear.
When rumors of the seven-speed Bronco surfaced in 2018, we were among those that theorized that the new transmission’s first gear would make for an excellent low-speed crawling tool, perfect for creeping over rocks and perilous terrain with utmost control. Now that it seems that our hunch was correct, let’s look at what Getrag’s newest information will mean for the 2021 Bronco.
With a 0.636:1 tenth gear and 4.696:1 first gear, the 10-speed Select Shift automatic in the current Ranger has an overall spread of 7.38. The new Getrag seven-speed promises a gear ratio spread of 11. Without knowing the ratio of the highest gear we can’t know the ratio of first gear, but we can make some educated guesses. If we look at the Jeep Wrangler, the vehicle likely to be the Bronco’s closest competitor, its Aisin D478 6-speed uses a 5.13:1 first gear and a 0.72:1 sixth gear. With an extra gear to work with, the seven-speed could offer a taller overdrive in sixth, but it won’t be anywhere near the triple-overdrive of the seven-speed manual found in the C7 Corvette. We’d wager on something in the 0.62:1 range. If that were the case, the Bronco’s first gear ratio would be 6.82:1. That seems incredibly low at first glance, but the classic Muncie SM465 four-speed had a 6.55:1 first gear.
Assuming the new Bronco gets a set of 4.11:1 ring and pinion gears to match its tall tires and the same two-speed transfer case as the current Ranger with its 2.717:1 low range, it would have a crawl ratio of 76:1, putting it between the 84.2:1 of the current Wrangler Rubicon six-speed and the 73:1 of the JK Rubicon six-speed, all without needing a 4.0:1 low range transfer case that Jeep employs. Of course, there’s no reason why Ford couldn’t also adopt a transfer case with a deeper low range in an attempt to out-crawl the current Rubicon.
No matter how the numbers break down, it looks like Ford is giving Bronco drivers plenty of off-road tools to work with. We won’t have much time to speculate, as Ford is unwrapping the Bronco this month.