33s and 373 gears

Frankie945

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What’s your thoughts on factory 373 gears and 33s with the 2.7 & 10 speed auto?
This will be my first Ford by far my first off-road vehicle, I’m sure that’s the same with many others on here but let’s face it how often do you really plan to wheel your new bronco. First I was going to get the Sasquatch package on my base trim but the more and more I thought about it I didn’t get it. Don’t want to look like a twinkie and 33s with the right tire/wheel and offset should look really good too and get better road handling with maybe 1 or 2 mpg more on the road. I think I’m going to go with more of a pre runner look and set up once I finally receive the bronco. I’ve done the jeep thing for years and honestly I’m kinda over it. I’m thinking the 373 gears with some 33s might be okay with the 2.7 and 10 speed just wanted to know other peoples thoughts on it. Peeps ran 35s and 373s on a jku with the 3.8L and 3.6L with no issues unless you were wheeling all the time or towing a lot.





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D2dhanover

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It will be fine. To put perspective on it: the heavier first gen Raptor on 35’s was given 4.10 gears and it was fine.

If you’re going to be doing a lot of crawling and climbing you might abuse things a little faster than normal but other than that it would be an okay combo if you don’t have the resource to change it out.

I have a SAS and non SAS Badlands on the way and the SAS will eventually be re-geared to 4.46 once the non sas gets modified more.
 

old goat

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im getting a base with 2.3 , AT , with 3.73 gears gonna put 32's on the bronc . not doing any wheeling just occasional off roading / hunting , mostly DD
 

AcesandEights

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I think 3.73 and 33" tires is marginal. I ran that set up for years and was disappointed with the crawl ratio (2.72 t-case). Lower (numerically higher) gearing would be preferable off road.
 
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Frankie945

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I think 3.73 and 33" tires is marginal. I ran that set up for years and was disappointed with the crawl ratio (2.72 t-case). Lower (numerically higher) gearing would be preferable off road.
But isn’t the 10speed geared little lower than the jeep 5 speed auto. That should make up some differences I think. I know the ring and pinion is going to be smaller with 373 compared to 4.10, 4.7 and so forth but when it comes to street driving I’d think it would be plenty powerful gearing wise with fords 10 speed and 2.7. I might have to just stop all my thinking wait and learn from others mistakes since I won’t have one till next year it’s looking like. I was just thinking out loud today with my post.
 

Beachin 74

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A stock Outer Banks (which comes with 3.73's) tire is 32.1" tall. A BFG KO2 285/70-17 (considered a 33" tire) is 32.8".
That's a difference of .7" tall or less than 3/8" on the radius.
I wouldn't worry about that little difference.
 

AcesandEights

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But isn’t the 10speed geared little lower than the jeep 5 speed auto. That should make up some differences I think. I know the ring and pinion is going to be smaller with 373 compared to 4.10, 4.7 and so forth but when it comes to street driving I’d think it would be plenty powerful gearing wise with fords 10 speed and 2.7. I might have to just stop all my thinking wait and learn from others mistakes since I won’t have one till next year it’s looking like. I was just thinking out loud today with my post.
I think so, I think you're right, but I'm not familiar with the Jeep auto.
 

AcesandEights

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Those are meaningless numbers without knowing the transmission gear ratios in between and the torque curve of the engine driving the wheels.
I guess I'd disagree. I don't think they're meaningless, but they only speak to part of the equation. If they were meaningless no one would ever talk about, or use in marketing material, crawl ratio.
 

Gamecock

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I guess I'd disagree. I don't think they're meaningless, but they only speak to part of the equation. If they were meaningless no one would ever talk about, or use in marketing material, crawl ratio.
Sure they would...crawl ratio takes into effect the entire system...including transfer case and transmission ratios. You can't just say the tire size and rear end gearing....you are leaving out 2 big pieces. That's why someone saying they had a Raptor or a Jeep with 4.10s and "it was fine" have no idea what they are talking about...it's apples and oranges unless you know the other numbers.

OP: Put all of the numbers in a gearing calculator, and you can see what it actually means. http://www.grimmjeeper.com/gears.html
If anyone claims it's fine because some other vehicle had the same final gearing and it was fine...pay no attention. It is not analogous.
 
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Bodge Garage

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3.73's are going to give you 53.8:1 final drive ratio in low range 1st gear. That is plenty if this is your first off road vehicle. You can roll on 33's with 3.73 all day long especially with the 2.7. Dont get caught up on have all sort of gearing or equipment you don't need just because it exists.
 

Mattwings

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As long as you recalibrate the ECM, it shouldn't be a huge issue. Vehicles are pretty sensitive to changes things like tire size these days. If you thought a V6Jeep JK with 35" tires and the v6 was OK, you will be blown away. I never owned one, but was in one and drove one, it was completely un-drivable to me. I did have a 4.0L 6 speed LJ with 32' tires and 3.73 gears, it was just OK, but really needed a re-gear. The base 2.3 has significantly more torque, the 2.7 will be night and day more powerful than the Chrysler V6. in I am not familiar with the transmission gearing, but my 2.7 10 sp F150 has 32" tires and 3.55 gears and accelerates and works off road very well. Pretty similar weight to the Bronco. No clue if they have significantly different gear ratios. I am curious why the Bronco has such "low" gearing relative to other vehicles with similar weight and power train.
 

Headsong

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Love this thread. Exactly this conversation as we drove back from s Dakota Prairie dogging. He has a ram pickup with high 200s...think back to 70s fuel mileage... But still only gets 19mpg on the hwy. So I even wonder if dropping to 3.73s would matter. I'm a BD with 32s no squatch.
 

_jeff

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Sure they would...crawl ratio takes into effect the entire system...including transfer case and transmission ratios. You can't just say the tire size and rear end gearing....you are leaving out 2 big pieces. That's why someone saying they had a Raptor or a Jeep with 4.10s and "it was fine" have no idea what they are talking about...it's apples and oranges unless you know the other numbers.

OP: Put all of the numbers in a gearing calculator, and you can see what it actually means. http://www.grimmjeeper.com/gears.html
If anyone claims it's fine because some other vehicle had the same final gearing and it was fine...pay no attention. It is not analogous.
Thanks for the link (y)
 

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