Transfer Case setting

[mikedibilio]

I am running 35s on my 2020 jLU and using a flashcal I have set my gear ratio at 4.56 (thinking of going to 4.88). What would you recommend that I set my transfer case at. At the current time, I am at 2.72 right now.

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[58Willys]

Have actually replaced your differential gears? If so with what ratio? You can’t just program ratios without having physically replaced gears.

 

[mikedibilio]

Have actually replaced your differential gears? If so with what ratio? You can’t just program ratios without having physically replaced gears.

I will be the very first to admit that this is totally outside my wheelhouse. But, my Rubicon has the stock lift that comes with it, and I increased to a 35 tire. I was told that I would not have to actually replace the gears unless I were to go with bigger tires (which I wont be doing). Any guidance here would be greatly appreciated.

 

[J.Ferreira]

I will be the very first to admit that this is totally outside my wheelhouse. But, my Rubicon has the stock lift that comes with it, and I increased to a 35 tire. I was told that I would not have to actually replace the gears unless I were to go with bigger tires (which I wont be doing). Any guidance here would be greatly appreciated.

You have a Rubicon and have your transfer case digitally set to 2.72:1?

...Why?

You have a 4:1 transfer case. Set it to 4:1.

Also do you have 4.56 gears? Or 4.10s?
If you have the (usually 4.10) Why do you have it set to 4.56?

 

[mikedibilio]

As I said, I am far from a "motorhead" here, so I am looking for advise from people with the expertise.

 

[ParadigmDawg]

Don't change anything except tire size

 

[azwjowner]

You're way down the wrong path here. Unless you physically changed the gears in your axles, that setting needs to be reset to factory -- what gears your Jeep actually came with.

Unless you physically swapped your transfer case (and it would be nuts to do so, because the 4:1 transfer case in the Rubicon is much better than a 2.72:1 case in the Sport), that setting needs to be reset to factory -- the 4:1 that your Jeep came with.

If you put larger tires on, the tire size setting is the only setting that you should change. That tells the Jeep computer what circumference your tires are, so when the sensor sees one revolution, it knows how far you've traveled (and what speed).

 

[mikedibilio]

Ok, this helps. When I reset to factory settings though, the gear ratio (2.73) is the one highlighted on the flashcal screen?

 

[KevinC11]

You are confusing us along with yourself.
With a Flascal, reset everything you messed with back to factory. If the transfer case was originally on 2.72, put it back.

Measure your tires under load. A 35" tire (depending on Manf) should be around 33.9-34.4 inch. Either measure up halfway ( ground to centerline of the hub) and x2, or just measure ground to top of tire.
That is the only value in Flascal settings you should be changing.

KevinC

 

[Ratbert]

Set all the settings to what you have, not what you want them to be.

Then drive down the interstate and verify that your speedo matches what sometimes like Waze / Google Maps says.

 

[Eyeball]

Set all the settings to what you have, not what you want them to be.

This is the only correct answer that can be given.

 

[mwilk012]

You have a Rubicon, 2.72 on the transfer case is wrong. Gear ratio for axles should be 4.10:1 and transfer case 4.0:1

 

[58Willys]

I will be the very first to admit that this is totally outside my wheelhouse. But, my Rubicon has the stock lift that comes with it, and I increased to a 35 tire. I was told that I would not have to actually replace the gears unless I were to go with bigger tires (which I wont be doing). Any guidance here would be greatly appreciated.

If you actually replaced the original 33” tires with 35” tires, then reprogram the tire size. Do not reprogram anything that you did not physically change. Reprograming parameters are to tell the computer that you have physically charged something, such as differential gears, it’s not for what you want.

 

[Pig-Pen]

Set all the settings to what you have, not what you want them to be.

Be the change you want to see.

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