Advice requested re regear for 315’s

[Russ2023]

Ok, I’m sorry for being responsible for yet another question about regearing. Trust me, I’ve been immersing myself on the subject to the point of feeling like I know less now than when I started. Even people who I was thinking of as pretty damn knowledgeable had contradictory opinions and advice.

So, my ride is a Texas Trail version. It came with the 3.73 gear ratio. I just upsized the tires to the BFG All Terrain T/A K02’s 315/70R17’s (C2).

I’m waiting on the Veepeak Bluetooth device and cable adaptor and currently I’m really only planning to modify the tire size and the gear ratio IF THE LATTER IS NECESSARY. I’m confident about the tire size needing to be recalibrated, but because of all the contracting opinions about the regearing I’m not sure what to do. I realize I could just play around with the setting until I’m satisfied, but I don’t really want to have to jack with that damn bar down there under the dash that makes access to the cables exponentially more difficult than it had to be.

The only other thing I can add is shifting in this thing is NOT impressive and it’s been that way since new. Never have the display set to where I can see the gear but it seems like it really sucks going from either 3rd to 4th or it might be 5th to 6th. I’m so used to it now I don’t really pay that much attention.

So anyway, I’d be forever thankful just to hear what you’d do. The area I’m in (bit west of Ft. Worth) is about as flat as it gets with the odd rolling hill added for good measure. I rarely have the opportunity to get off-road and it’ll never be climbing rocks. I’m leaning towards 4.10 but I know there’s a lot of people that would say stay with the 3.73. As I was saying, I realize I could just play with it and see how it drives between 3.73 and 4.10, but I’d really rather have to jack with that bar down there once. My hands are just way too big for getting in and out of that area.

‘Thanks a ton for listening. I appreciate it.

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[DarthAWM]

Once you recalibrate for the tires it should shift better. If you don’t mind the way it drives don’t bother regearing.

I waited a couple days after installing 37's before recalibrating and it does make a significant difference.

 

[Russ2023]

Once you recalibrate for the tires it should shift better. If you don’t mind the way it drives don’t bother regearing.

I’m Ok with the way it drives in general, but the shifting between those gears I mentioned is a bit rough. Almost like it’s straining itself a bit before it shifts. But right now I’m leaning towards doing as you say and just recalibrating and drive it a while and then reevaluate. Thanks.

 

[Russ2023]

I waited a couple days after installing 37's before recalibrating and it does make a significant difference.

Yea, with 37’s I sense there’s a clear consensus that regearing is necessary. But I only went with the equivalent of 35’s and there’s anything BUT any kind of consensus with that size.

 

[dayusmc]

My wife's JLU High-Tide came with 35s and 4:56 from the factory and it is perfect. I would do 4:56

 

[bleda2002]

Uh, regearing means opening the diffs and swapping the gears, not just changing it in the tazer/jscan. Your post made it seems like you think you just need to swap between the numbers but that's not true.

Swap the numbers for the tires so the speedo is right, the gear ratio needs to match what's installed in the diff though.

 

[dayusmc]

Uh, regearing means opening the diffs and swapping the gears, not just changing it in the tazer/jscan. Your post made it seems like you think you just need to swap between the numbers but that's not true.

Swap the numbers for the tires so the speedo is right, the gear ratio needs to match what's installed in the diff though.

Exactly. And my trsin of thought is that if they put 4:56 in from the factory with 35" tires, that is probably what is best. My wife's jeeo shifts perfect.
In fact I am trying to figure out the exact same "ratio" for 37" tires for my gladiator
35" = 4:56
37" = ??? To be the same as the above..

 

[bleda2002]

Exactly. And my trsin of thought is that if they put 4:56 in from the factory with 35" tires, that is probably what is best. My wife's jeeo shifts perfect.
In fact I am trying to figure out the exact same "ratio" for 37" tires for my gladiator
35" = 4:56
37" = ??? To be the same as the above..

4.88 is about the same for 37s as 4.56. I went one step more to 5.13s since 37s are generally heavier and more resistance than 35s

 

[Russ2023]

Uh, regearing means opening the diffs and swapping the gears, not just changing it in the tazer/jscan. Your post made it seems like you think you just need to swap between the numbers but that's not true.

Swap the numbers for the tires so the speedo is right, the gear ratio needs to match what's installed in the diff though.

Ok, there’s a perfect example of something I’m completely confused about after perusing what felt like a million conversations I’ve seen here and elsewhere. I’ve even seen posts where people say an axle swap is necessary.

You may absolutely be right, but I’ve seen so many posts here and elsewhere where it seems equal number of people say physical gear changes are required and others say it’s overkill or completely unnecessary. I called the local off-road shop that’s done work on my previous Jeep and he said I should be good to go with the JScan.

I’m starting to wonder if there isn’t an absolute right or wrong way to go.

 

[Russ2023]

My wife's JLU High-Tide came with 35s and 4:56 from the factory and it is perfect. I would do 4:56

I’ve been thinking of doing 4.10 but now you’ve got me thinking. Thanks a ton.

 

[bleda2002]

Ok, there’s a perfect example of something I’m completely confused about after perusing what felt like a million conversations I’ve seen here and elsewhere. I’ve even seen posts where people say an axle swap is necessary.

You may absolutely be right, but I’ve seen so many posts here and elsewhere where it seems equal number of people say physical gear changes are required and others say it’s overkill or completely unnecessary. I called the local off-road shop that’s done work on my previous Jeep and he said I should be good to go with the JScan.

I’m starting to wonder if there isn’t an absolute right or wrong way to go.

Jscan can set tire size and gear size, but those numbers need to match what's physically installed on the truck.

 

[dayusmc]

I’ve been thinking of doing 4.10 but now you’ve got me thinking. Thanks a ton.

Sorry. But I can truely say without a doubt if I was going to stay with the 35" on my gladiator (currently I have 4:10 and 35") I would upgrade to the 4:56, it is that big if a difference between her Jeeo and mine. On the highway her's is always in 8th gear, mine always drops to 6th or 7th gear.

 

[Erievon]

If you had 4.10s already, I'd say stay there. But please, do not spend the money going to 4.10s. If you're spending the money and cracking open the diff, go to 4.56.

I think of it as +1 vs +2. 3.73 to 4.10 is a +1, and not worth it. But 3.73 to 4.56 is +2.

Or for a Rubi or Mojave (Or Max TOE), 4.10 to 4.56 is +1 and not worth it, but 4.10 to 4.88 is +2.

 

[Wheelin98TJ]

Ok, there’s a perfect example of something I’m completely confused about after perusing what felt like a million conversations I’ve seen here and elsewhere. I’ve even seen posts where people say an axle swap is necessary.

You may absolutely be right, but I’ve seen so many posts here and elsewhere where it seems equal number of people say physical gear changes are required and others say it’s overkill or completely unnecessary. I called the local off-road shop that’s done work on my previous Jeep and he said I should be good to go with the JScan.

I’m starting to wonder if there isn’t an absolute right or wrong way to go.

Gearing is subjective. If you are fine with how it accelerates and what gear it cruises in on the highway, you do not need to regear.

I’ve been thinking of doing 4.10 but now you’ve got me thinking. Thanks a ton.

3.73 to 4.10 is not a big enough change to warrant the cost.

 

[Erievon]

If you're spending the money and cracking open the diff, go to 4.56.

And in the name of Scope Creep, might as well throw an e-locker or an lsd in the rear....and a switch controller for it...and...I'll shut up now.

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