JTRD on 37" what ratio 4:56 or 4:88

[Jchap1987]

WOW.... that is why I love this forum.
thank so much for good information.
so it Is a BIG NO for 4:88 (I call Yukon and it tell me to used 4:88)

I narrow it down to two 4:11 or 4:56,
I think I will go with 4:56 because I do some towing and I think it will put me closest to factory



I was not thinking of a front track bar! do I need one

Yes. You need to recenter your front axle. ESP since you have a new rear one. They need to match

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[Reddout99]

You will be fine with the stock 4.10 gears on your JTRD.

Jut as an FYI, KO2s typically run a little small and you may not need the Clayton track bar out back, unless you want one for the long run. A front adjustable would be needed to center the axels up after the lift.

Are you adding the 3/4" spacer in the front or rear since you tow a lot?

 

[rharr]

You will be fine with the stock 4.10 gears on your JTRD.

Jut as an FYI, KO2s typically run a little small and you may not need the Clayton track bar out back, unless you want one for the long run. A front adjustable would be needed to center the axels up after the lift.

Are you adding the 3/4" spacer in the front or rear since you tow a lot?

No Diesel comes with 4:10, they all get 3:73 despite what window stickers say.

 

[Reddout99]

No Diesel comes with 4:10, they all get 3:73 despite what window stickers say.

I thought they did, based on it being a Rubicon. Thanks for the correction. I got smarter today

 

[Rusty PW]

I'll be honest, I missed the diesel part of the equation

You miss a lot.

 

[Rusty PW]

EAV and the Dealer "MOPAR" is using 4:56. why they (EAV & Mopar) are not using 4:88 ? and the other hand I call Yukon and it tell me to used 4:88
and also don't forget about 4:11
I will not ever go to 40"

I am on the process of install Mopar 2" lift and Daystar 3/4" Comfort Ride Spacer.
clayton adjustable rear end track bar ( so I can put a spare 37" underneath )

tire are heavy 37x9.5x12 ta ko2 back rhino.

I used my jeep 35 % towing (rv 5,000). 15 % off road, (5% towing off road gravel Road )
50 % city and high.

current at 65-69 towing the rv getting 18-19 mpg.

You will need a track bar in the front too. The Mopar lift will give you over 2.5" of lift. Add another 3/4". You'll need it. You might want to go with 3" ~ 4" shocks too. You'll be close to topping out the Mopar lift shocks.

 

[Minty JL]

You miss a lot.

I guess so

 

[CrazyCooter]

3.73's worked well with 37's, but 3.92's would be best if you tow a heavy trailer with wind drag in the mountains......they don't make them, so I went 4.10's and 38's to balance it out.....perfection!

 

[wildtaco]

Love how most of the advice not to regear is from gasser owners. Don't make your decision based on these answers. The decision on whether or not to regear will all depend on how you use your Jeep. This diesel specifically has cooling issues and does not like high EGTs (exhaust gas temperatures). Putting larger tires using stock gearing will put more strain on the engine, increasing temperatures across the board. I fought mine driving across the US while pulling a camper. It was constantly going into limp mode.

Now, again, whether or not you will see any effects of the higher temperatures will depend on how you use the Jeep. Do you tow a camper/trailer on the weekends? Do you have a heavy overland setup? Or is it a fairly light build and you simply commute with your Jeep? The latter, I would probably skip the regear and see how it does. The former, I would absolutely regear.

I tow reguraly, so I regeared my JTRD with 35s to 4.56 which is excessive, but only slightly so. I did this because I plan on switching to 37s next time I need tires. It honestly does great as it is already. Very curious on how it will be with some 37s.

 

[GI Grandpa]

EAV and the Dealer "MOPAR" is using 4:56. why they (EAV & Mopar) are not using 4:88 ? and the other hand I call Yukon and it tell me to used 4:88
and also don't forget about 4:11
I will not ever go to 40"

I am on the process of install Mopar 2" lift and Daystar 3/4" Comfort Ride Spacer.
clayton adjustable rear end track bar ( so I can put a spare 37" underneath )

tire are heavy 37x9.5x12 ta ko2 back rhino.

I used my jeep 35 % towing (rv 5,000). 15 % off road, (5% towing off road gravel Road )
50 % city and high.

current at 65-69 towing the rv getting 18-19 mpg.

You're in Texas, do you tow? If you don't tow, but you may go bigger than 37" down the road, I'd go with 4.88 and be done with it.

 

[JO_178]

I'm running 5.13 Yukon's with 37's. Glad I did. 2024 Willys Edition

 

[mgenbox]

3.73's worked well with 37's, but 3.92's would be best if you tow a heavy trailer with wind drag in the mountains......they don't make them, so I went 4.10's and 38's to balance it out.....perfection!

What lift and height you runnin?
My 3.73s on 35s tow 5k on stock Rubi good but would like to go 37s eventually

 

[yrwins]

Ok,
I normal take the Sumer off, and towing for 2 to 3 months the RV.

yes, the jeep is a little bit heavy.

 

[Rusty PW]

I'm running 5.13 Yukon's with 37's. Glad I did. 2024 Willys Edition

Diesel or gas?

 

[JO_178]

Gas, they don't have diesel anymore. I wish they kept it.

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