JL gearing and tire size

[TheDLG]

Do you think the gearing available in the jk will carry over to the jl or will the jl offer different gearing like 4.56. Also what are the chances that the jl will be able to push 35's without the issues like premature wear the jk has?

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[The Great Grape Ape]

Do you think the gearing available in the jk will carry over to the jl or will the jl offer different gearing like 4.56. Also what are the chances that the jl will be able to push 35's without the issues like premature wear the jk has?

It's an unknown because it appears to be a new 12-bolt axle, which means it's not a D30 or D44 so that might mean totally different ratio options.

I would say it's guaranteed that there will not be a ratio higher than 4.10 , and even there being a 4.10 ratio as a stock option might also be up for debate, as the new ZF-8 speed's first gear ratio and spread are greatly improved over the previous transmissions.
With the same 4:1 RockTrac TC, the new crawl ratio for a 3.73 axle and ZF auto transmission will be 74.6 which is greater than the crawl ratios using 4.10 axles on the current manual transmission @ 73.2 and auto @ 58.9.

However the options could be completely different as they don't rely on the legacy platform with this new axle which is on Dama's new AdvanTek platform that focuses on efficiency, so instead of 3.21 / 3.73 / 4.10 you might see 3.08 / 3.55 / 3.91 as stock options, or there may be no change.

No one outside of those with access to the early examples know, but like I said, it can pretty much be guaranteed there won't be a stock ratio larger than 4.10, and even the range of oem / 3rd-party upgrades is still unknown.

 

[TheDLG]

It's an unknown because it appears to be a new 12-bolt axle, which means it's not a D30 or D44 so that might mean totally different ratio options.

I would say it's guaranteed that there will not be a ratio higher than 4.10 , and even there being a 4.10 ratio as a stock option might also be up for debate, as the new ZF-8 speed's first gear ratio and spread are greatly improved over the previous transmissions.
With the same 4:1 RockTrac TC, the new crawl ratio for a 3.73 axle and ZF auto transmission will be 74.6 which is greater than the crawl ratios using 4.10 axles on the current manual transmission @ 73.2 and auto @ 58.9.

However the options could be completely different as they don't rely on the legacy platform with this new axle which is on Dama's new AdvanTek platform that focuses on efficiency, so instead of 3.21 / 3.73 / 4.10 you might see 3.08 / 3.55 / 3.91 as stock options, or there may be no change.

No one outside of those with access to the early examples know, but like I said, it can pretty much be guaranteed there won't be a stock ratio larger than 4.10, and even the range of oem / 3rd-party upgrades is still unknown.

How about the components like ball joints and such. I plan on buying a jlu and putting on 35's but I don't want to have to replace things to prevent premature wear.

 

[Billy]

I had heard from multiple sources that the JL was designed to fit 35s without lifts or mods, so it would stand to reason that the components would be designed with consideration of such.

 

[Artec]

The wheel openings look huge, I wouldn't be surprised if you can't stuff a 35" tire stock.

 

[Billy]

The wheel openings look huge, I wouldn't be surprised if you can't stuff a 35" tire stock.

Again, from what I've been reading, 35s will fit a stock Rubicon. The rock rails were specifically designed to clear 35s. Which I translate to fitting them in the wheel well too.

 

[WXman]

Jeep is designing the JL to be capable of 35s. However, from the showroom floor they are still concerned about fuel economy. So the Rubicon is the only model getting the 33s, and they will be a lightweight 33 at that. As mentioned, the transmission ratios make up for the gearing so I don't expect the options to change. The new axle is reportedly just a beefed up D44. They did the same thing on JK back in 2008 when they switched from a rear D35 to a beefed up D44. Now we're going to get yet another upgrade to the D44. Question is...will the actual ring and pinion remain the same to allow easy gear swaps as soon as the vehicle goes on sale?

 

[wanderer]

Not sure but I saw that the 2017 recon has a beefier d44 it is listed differently form the regal D44 on the rubicon. I think it has larger axle tube and a larger cjoint.

 

[Artec]

Yes, that is correct Larger C's and axle tubes on the recon editions

 

[The Great Grape Ape]

Not sure but I saw that the 2017 recon has a beefier d44 it is listed differently form the regal D44 on the rubicon. I think it has larger axle tube and a larger cjoint.

Yes, but the JL is a whole new axle, even Dana announced it would be a new axle when they broke ground for their new plant in Toledo.

The Recon has a reinforced D44 that is still a 10-bolt diff cover and very much a rounded hexagon both fron5 and back, the Recon variant is essentially what Dana markets as "The Ultimate Dana 44";
http://spicerparts.com/parts/axle/a...mate-dana-44-front-axles-for-jeep-wrangler-jk

The new 12-bolt diff cover on the JL appears a bit bigger and a lottle more defined edges to the point of being an octagon. This means a new axle. The only previous DANA light truck/car axle with a 12-blot pattern was the DANA 28, but it was very light duty, however DANA might extend that type of numbering and make the new Axle the DANA 48 to denote it being bigger than the 44 but less than the 60, but no one knows at this point. Although it is likely using some form of DANA's new AdvanTEK platform;

http://www.dana.com/~/media/danacom...les-featuring-advantek-gearing-spec-sheet.pdf

New Axle

Edit: Added rear D-U44 and another view of JL Rubi rear for comparison.

 

[WXman]

Hopefully they're going to use at least some internal parts that can interchange.

 

[Armycop]

I'm curious about the gearing too. I'm guessing the 4 cyl will be the one for max gas mileage so geared more toward highway/smaller tire use for the grocery hauler duties. The Rubicon I'm guessing somewhere in the 4.10 range again with the slightly larger tires. The 6 cyl models should stay similar to the JK.

 

[four low]

The tire size listed for the base model is 245/75/R17. That's a 31"diameter , I believe. The 4 cylinder will probably have 4:10, at the minimum number. I'm hoping the 6 cylinder " improved" PentaStar will have 3:73 as standard gear ratio.
Shelling out $ 700 for the 3:73 hurts. The 3:21, now standard, is strictly for mpg.

 

[Armycop]

I don't understand why you used to be able to get 4.10 gearing optional on a "X" model back when I bought mine for about $40 and they jacked up the price in later years so much.

 

[DanW]

I don't understand why you used to be able to get 4.10 gearing optional on a "X" model back when I bought mine for about $40 and they jacked up the price in later years so much.

My 93 YJ 4 cylinder had 4.10 gearing and pretty small tires. My JKUR is running 33.5" BFG's and does fine with 4.10's, and it has just over 200hp. If the torque is close on the 2.0 turbo to the 3.8, then it will do fine with 3.73's or 4.10's. I'm hoping the JLUR has 4.10's with the 33's, and a little weight loss, along with a little power boost for the 3.6. That should be a nicely powered package. (I'm still crossing my fingers that the diesel is available early, though.)

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