Need Help : 456 gear ratio for 37" tires

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Jimboliath

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Love this community...

I have a mid-travel built 2013 Raptor with 37" tires. I still have the stock axle, diff, driveshaft, and transmission.

From my research, i believe i want to go with the 456 gear ratio, simply to save some highway mileage.

My questions to you guys are:
-Where can i buy everything i need?
-What else, other than the actual install, do i need to get done for this to run as smooth as possible with all my instruments? (transmission programming...etc)
-Can i take the gears i want to ford and say "here i want this gear ratio and all my instruments synced up to work with it"
 

letsgetthisdone

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For 37's, do 4.88's. IMO, the truck is undergeared already with the facotry 35's and 4.10. 37's with 4.56 is about the same as stock. The 37's are heavier, so going a bit shorter than stock with the 4.88's with 37's will be the best choice IMO.
 

DreamcastERA

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Nitro Gear makes full kits that come with everything - it's essentially a full rebuild of the differential. Bearings, seals, the gears themselves - everything. I personally went with 4.88. People haven't generally had the best experience getting Ford to reprogram stuff like this. I would recommend the 5 Star tune route. It will reprogram all of your dials - account for both gear ratio and tire size. Some people have reported that the transmission shifts were a little bit odd after changing gear ratio - before reprogramming. However - in your case, it might not be that bad - due to the fact that you're going back to a similar relationship to stock between tire and gear ratio. Yukon gear is also a good option.

Speaking of - you're engine RPM at 65 MPH in 6th gear will look like this under each scenario:

Stock (4.10 w/ 34.5"): 1791 RPM in 6th gear
Current (4.10 w/ 37): 1670 RPM in 6th gear
4.56 w/ 37": 1857 RPM in 6th gear
4.88 w/ 37": 1988 RPM in 6th gear

Hope some of that info was helpful!

Best of luck!
 

Chris NP-C

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Ok, so here’s the deal...

I have a drivetrain “warranty forever” plan and so I can’t muck with the engine or anything too obvious. I am currently upgrading to 37” tires and know I’m about to lose acceleration.

I figure differential gearing would do a lot for that without being obvious to anyone. I’ve seen that 4.88 would be about right in terms of coming close to stock gearing given the tires.... but, would I be totally off base to go with 5.13 for the 0-60 and off roading I do in the mountains?

I know I’ll likely have to get a 5 star tuner to adjust for the tires and speedo.

I don’t do a ton of highway driving and so going from 12.7 to perhaps 12.4mpg isn’t distressing me too much.
 

1BAD454SSv2

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If i had to do over again i would go 4.56 supercharged and 4.88s non boosted. I have 4.88 supercharged with 37s and 1st and 2nd gear is over too quick then pulls good 3rd and 4th gear. Its a decision you want to make once because of the cost to install gears
 
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If i had to do over again i would go 4.56 supercharged and 4.88s non boosted. I have 4.88 supercharged with 37s and 1st and 2nd gear is over too quick then pulls good 3rd and 4th gear. Its a decision you want to make once because of the cost to install gears

any way you can post up a vid I’d love to see some acceleration with those gears. I’m supercharged and considering 4.88’s looking to see what it looks like. Thanks in advance if you can.
 

PorterW1111

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Love this community...

I have a mid-travel built 2013 Raptor with 37" tires. I still have the stock axle, diff, driveshaft, and transmission.

From my research, i believe i want to go with the 456 gear ratio, simply to save some highway mileage.

My questions to you guys are:
-Where can i buy everything i need?
-What else, other than the actual install, do i need to get done for this to run as smooth as possible with all my instruments? (transmission programming...etc)
-Can i take the gears i want to ford and say "here i want this gear ratio and all my instruments synced up to work with it"
Sdhq sells the nitro kits. But to be clear they come with all the “parts” you need to change the gears.

I add that clarification as this is not a job the average person will be able to do. Special tools are required and precision is key. To be honest this is a job I have an issue trusting most shops to do. 100% find a shop that has done raptor gear changes for the front and rear multiple times.

5.13 is not a good idea, the front diff is small and going with a 5.13 the pinon gets too small and can break if your tires were to hook up wrong.

gas mileage will go down to around 9-10mpg.
I have yet to see a truck with gear change that is actually accurate on the gauges even after a tune. But yes you will need a tune. Just saying you may notice your speedo is progressively off.

if you are going to do gears it’s also a good idea to change to a larger diff cover. There have been some discussion about the higher capacity square covers vs the ford performance covers, I’ll let you dig on that and see which side you agree with. In short it’s likely your new gears will be hotter so you’ll need more fluid and a cover that is fined to help keep it cool.

To help with pricing what I have seen is your looking at $1,200 for the kits and anywhere from 1000-2500 for install.

My opinion marginal gains for the cost/risk of exploding a pumpkin.
 

myersroofer614

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Nitro Gear makes full kits that come with everything - it's essentially a full rebuild of the differential. Bearings, seals, the gears themselves - everything. I personally went with 4.88. People haven't generally had the best experience getting Ford to reprogram stuff like this. I would recommend the 5 Star tune route. It will reprogram all of your dials - account for both gear ratio and tire size. Some people have reported that the transmission shifts were a little bit odd after changing gear ratio - before reprogramming. However - in your case, it might not be that bad - due to the fact that you're going back to a similar relationship to stock between tire and gear ratio. Yukon gear is also a good option.

Speaking of - you're engine RPM at 65 MPH in 6th gear will look like this under each scenario:

Stock (4.10 w/ 34.5"): 1791 RPM in 6th gear
Current (4.10 w/ 37): 1670 RPM in 6th gear
4.56 w/ 37": 1857 RPM in 6th gear
4.88 w/ 37": 1988 RPM in 6th gear

Hope some of that info was helpful!

Best of luck!
Exactly what I needed, thank you
 
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