5.38 Gearing Ration Offered by Ford Performance

Retnuh D

Mar 31, 2025

Mon at 3:19 pm

I have a newly acquired Bronco Badlands SAS 2.3L MT and of course the first thing I do (as we all do) is fantasize about what new components/mods to get. I stumbled upon the 5.38 ratio Ring and Pinion for the Bronco and am wondering if it is a worthy investment, or if anyone has installed one yet in their Broncos, or if it is even compatible. In the near future I am planning on getting the Ford Pro-cal to give it a wee bit of boost and then further in the future potentially putting 37s on it (with an additional two inch lift to compensate for the size difference)... Regardless if I do not put 37s on the vehicle what are some changes I should expect or is this something I should avoid until I am willing to throw more money at Ford for the new ratio/drivetrain install.

TL/DR: Is the 5.38 worth the squeeze?

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Tue at 8:23 pm

For offroad you can't go low enough.With bigger rubber you have to change gear ratios.

Joined May 29, 2020 Member 546
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Yesterday at 8:50 am

Bronco V-8
For offroad you can't go low enough.With bigger rubber you have to change gear ratios.

If I were to put the 5.38 in currently with 35s what should I expect? Higher RPMs on highways, worse gas mileage, but hella torque in low range?

Basically is it a wait and buy or a buy now and embrace the power?

Yesterday at 9:39 am

What gears do you have now and what tires?
The effect of gear changes is based on rolling radius not diameter, using diameter will give an incorrect result, making a gear change look much greater than it actually is.

https://www.sciencedirect.com/topics/engineering/effective-rolling-radius

Joined May 29, 2020 Member 546
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Yesterday at 10:21 am

Bronco V-8
What gears do you have now and what tires?
The effect of gear changes is based on rolling radius not diameter, using diameter will give an incorrect result, making a gear change look much greater than it actually is.

https://www.sciencedirect.com/topics/engineering/effective-rolling-radius

Factory, I took delivery in February. I have the 35s that come with the Sasquatch package.

Chief Ron

Yesterday at 2:30 pm

Yeah, you'll basically get more low-end torque, lower top-end speed, and a minor hit to fuel economy on the highway. Good for off-roading, bad for everyday driving—like everything there is a trade-off.

My personal "best ratio" opinion below. Trying to focus on off-roading without completely sacrificing everyday drivability. Essentially someone that really enjoys off-roading, but still drives it everyday. Folks are welcome to fight me on my opinion 😉

10-speed auto
- 33s: 4.46
- 35s: 4.70
- 37: 5.13
- >37: 5.38
7-speed manual
- 33s: 4.70
- 35s: 5.13
- 37+: 5.38

All that said... frankly for most people, if you already have 4.70 axles, it doesn't make sense to swap them.

2022 4dr Badlands, 2.3L Manual, Mid pkg
YouTube: youtube.com/@ragnarkon
Instagram: @ragnar.kon

Chief Ron, J.bell

Yesterday at 3:12 pm

I have a Braptor, I believe the axle gear ratios there from the factory are 4.70. I have no complaints on the low end that's for sure.

2024 Ford Bronco Raptor - Shelter Green - Order Confirmed 9/21/2023, Scheduled 1/29/2024, In Production 2/2/2024, Built 2/23/204, Shipped 2/25/2024, Delivered 3/12/204.

Chief Ron, Sven

Yesterday at 5:10 pm

RagnarKon
Yeah, you'll basically get more low-end torque, lower top-end speed, and a minor hit to fuel economy on the highway. Good for off-roading, bad for everyday driving—like everything there is a trade-off.

My personal "best ratio" opinion below. Trying to focus on off-roading without completely sacrificing everyday drivability. Essentially someone that really enjoys off-roading, but still drives it everyday. Folks are welcome to fight me on my opinion 😉

10-speed auto

33s: 4.46

35s: 4.70

37: 5.13

>37: 5.38

7-speed manual

33s: 4.70

35s: 5.13

37+: 5.38

All that said... frankly for most people, if you already have 4.70 axles, it doesn't make sense to swap them.

Do you know if the 5.38 from Ford is plug and play or does it require new axles?

Yesterday at 7:37 pm

Retnuh D
Do you know if the 5.38 from Ford is plug and play or does it require new axles?

If you already have lockers it's plug-n-play.

Although swapping out gears is really more like "install, then remove, then reinstall, then rinse/repeat ad-nauseum until you finally get it right... then play, hopefully, someday". It's not a super easy task if you've never done it before, there is a bit of an art to getting the backlash and gear depth correct. And frankly most of us don't have that skill, so it really just means we get to trial-and-error for hours on end.

But if you have done different gear swaps before, then yeah... it's not bad. Just swap the rear different gears, swap the FDUs, and program the modules with a Procal.

2022 4dr Badlands, 2.3L Manual, Mid pkg
YouTube: youtube.com/@ragnarkon
Instagram: @ragnar.kon

Chief Ron

Yesterday at 11:10 pm

RagnarKon
If you already have lockers it's plug-n-play.

Although swapping out gears is really more like "install, then remove, then reinstall, then rinse/repeat ad-nauseum until you finally get it right... then play, hopefully, someday". It's not a super easy task if you've never done it before, there is a bit of an art to getting the backlash and gear depth correct. And frankly most of us don't have that skill, so it really just means we get to trial-and-error for hours on end.

But if you have done different gear swaps before, then yeah... it's not bad. Just swap the rear different gears, swap the FDUs, and program the modules with a Procal.

I used to set backlash for the local dealer.An indicator and Dykem is all you need to check it.Helps if you are a gearhead and toolmaker.
Not arguing on the subject but with the four and the 7 spd in hilly country like here, you need the lower gears so you aren't shifting all the time, especially if you tow.

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