Hey fellow JKers,

I just had a question - hopefully someone has dealt with this one already. I'm ordering a 2013 JKU Rubicon to replace my current 2012 with engine/manual trans issues and I'm looking at ordering the auto instead of manual this time. If I do this, I plan to go for the optional 4.10 gears (2013 auto rubicons come with 3.73 standard, have to pay for the upgrade to 4.10).

I'm wondering... if I upgrade to a 33 inch tire... will a ProCal be necessary to switch the shift points? Being the 4.10 gears run at a higher RPM on these 2013 auto rubicons, I'm wondering if bumping up from the stock 32 inch tire to a 33 inch tire will really require the shift point change or if it will still shift at the appropriate RPM. I'm not too concerned with the speedometer being off a few MPH... just want to make sure it will still shift appropriately.

Thanks for any help you can offer. Happy new year!

 

I have a Rubi with the 4.10 gearing & 5 speed auto trans. I didn't want to leave it to chance, I went ahead and got the Procal for that reason as well as the option to turn off the TPMS since I am running aftermarket wheels w/out installing the sensors.

 

I've got the 2013 jkur, and upgraded to 34" wheels. I've got the 3.73 still, and I see no reason to change anything.

It's all about preference, and up to you. I spend a lot of time on the freeway, and no problems what so ever.

 

Right on - did you try to run it at all without the procal updating the shift points? Just curious how it would shift without changing them. Awesome looking Jeep btw - do those tires handle well on the highway?

 

Thanks for the reply! Do you find that it shifts differently/worse than stock?