Differential gear ratio calculator

[kodiakisland]

I see a lot of questions on gears and thought I would post this link:
http://www.grimmjeeper.com/gears.html
Don't just look at one of those generic charts based on a 1:1 drive ratio.

I think this is one of the best calculators out there to see what YOUR vehicle will really do. I see so many people trying to compare to other vehicles and what gears they have, when that's completely irrelevant. This will tell you what YOUR vehicle rpms will be in every gear. Keep in mind not all motors need the same RPM for best usage.

At some point they will have the Bronco transmissions and transfer case in the database, but until then just put in the data manually. We know all the ratios for the manual and automatic transmission, so just put in the correct numbers and put the actual tire size and start changed the gears to see what it does. You might be surprised to see what the RPM is for say, 60mph or 80mph in 5th or 6th gears (9th or 10th for auto).

4.70s are not going to be too low for most applications.

Here are the numbers to put into the calculator. Be sure and put in the correct number of gears at the top so it will calculate for every gear. You don't have to put in the transfer case numbers unless you just want to see what the low range does, as it defaults to a 1:1 ratio.

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[Stampede.Offroad]

I haven't seen these prelim specs before, is it the same set of 10sp gears as the rest of the 10R80's ?

 

[HoosierDaddy]

I haven't seen these prelim specs before, is it the same set of 10sp gears as the rest of the 10R80's ?

That's exactly what the Grimjeeper calculator auto populates if you choose the 10r80 for the transmission, so I'd say yes, those are the typical gears in that tranny.

 

[CrazyMonkeyBen]

Numbers for the 2021 Bronco have been added to the database.

select Ford 10R80 for the automatic or Ford MT88 for the manual

select Ford Bronco 2021+ 2.72 for the standard transfer case or Ford Bronco 2021+ 3.06 for the advanced transfer case

 

[grimmjeeper]

I just created an account to post here that I added the Bronco information to the calculator.

I put the transmission in as both the Ford MT88 and the Getrag 7MTI550. Both will give you the same numbers.

I didn't know what transfer case brand/ID to call them so I put in "Ford Bronco 2021+" for both of them.

If I got any information wrong or if someone knows the names of the transfer cases, let me know and I'll update the page.

 

[kodiakisland]

I just created an account to post here that I added the Bronco information to the calculator.

I put the transmission in as both the Ford MT88 and the Getrag 7MTI550. Both will give you the same numbers.

I didn't know what transfer case brand/ID to call them so I put in "Ford Bronco 2021+" for both of them.

If I got any information wrong or if someone knows the names of the transfer cases, let me know and I'll update the page.

Thanks!
That's by far the best calculator I've used for several vehicles when re gearing.

 

[grimmjeeper]

Thanks!
That's by far the best calculator I've used for several vehicles when re gearing.

I'm happy people find it useful. I've planned out several builds with it since I first was building my old CJ7 back in the early 2000's.

And don't tell all my Jeep friends but I've been looking at getting a Bronco to be my daily driver/moderate trail rig to go along with my 87 Comanche on tons and 40's.

 

[Rockdawg84]

its interesting to me that the JL Rubicon Wrangler is at 77.24:1 in first gear and the new bronco with SAS and Auto will only be 67.79:1. interestingly that means that on 33's it would be almost identical which is what the JL comes with stock. if we could get a 4.0 transfer case gear set then we could be at 88.62:1. but really we will need to get to a 4.7 gear set to get us to the magical 104:1 crawl ratio. Just saying

 

[grimmjeeper]

It was brought to my attention that I must have screwed something up and accidentally erased the manual transmissions for the Bronco at www.grimmjeeper/com/gears.html

I have restored the listings, both as the Ford MT88 and the Getrag 7MTI550.

I apologize for that mistake.

 

[telenerd]

It was brought to my attention that I must have screwed something up and accidentally erased the manual transmissions for the Bronco at www.grimmjeeper/com/gears.html

I have restored the listings, both as the Ford MT88 and the Getrag 7MTI550.

I apologize for that mistake.

Howdy I tried using the gear calculator for my Sasquatch Badlands and could not figure out what to put for some of the values.

Can you make one for dummies and just have Bronco for the selection boxes?

Or if @kodiakisland wants to share his Sasquatch Badlands results that works too.

 

[kodiakisland]

Howdy I tried using the gear calculator for my Sasquatch Badlands and could not figure out what to put for some of the values.

Can you make one for dummies and just have Bronco for the selection boxes?

Or if @kodiakisland wants to share his Sasquatch Badlands results that works too.

It seems the MT has been removed from the list, so I just manually enter my transmission numbers. The auto is still there.

 

[telenerd]

It seems the MT has been removed from the list, so I just manually enter my transmission numbers. The auto is still there.

Thanks what do I select from the transfer case and under drive? There is a high, low, and low range 2 for fields on the transfer case and have no idea what the under drive field is. No clue what to put for values based on ford charts for my automatic Badlands Sasquatch.

 

[kodiakisland]

Thanks what do I select from the transfer case and under drive? There is a high, low, and low range 2 for fields on the transfer case and have no idea what the under drive field is. No clue what to put for values based on ford charts for my automatic Badlands Sasquatch.

I usually only enter values for transmission, tire size, and gear ratio. You can leave the others set a none, which will give a 1:1 value for them. If you want to see your low range, you can manually enter your low transfer case number, which depends on if you have 4A or not.

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