So let me get this straight...?? (2012's and re gearing)

Sola_Christos said:
So, if I have a 2012 JK 4dr (with Pentastar engine)and I decide to run 35/12.5....I do not need to re gear my rig?? Please feel free to chime in on this one guys! :thinking::dont_know::confused::question::pop2::hmm:
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I have a 2012 automatic unlimited with 35's and 3.21 gears. No problems here! Just get a programmer to set for tire size and you'll be good!
 
rtguy1 said:
that would depend on the factory gearing ratio you have. 4.10's work fine for 35's, 3.73 is ok. 3.21 is poor even with stock tires
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Getting bitten by a great white shark is slightly better than 3.21s. Ask me how I know. :( I have a 2012 JKU Auto on 33s and I want to slit my wrists. If you live anywhere with hills you'll want to slice your wrists in both directions.
 
Yeah I have 3.21, 35s with a Procal and highway is still painful. I run the TGs at 28 PSI cold which measured around 34 from ground to top but after I got home this afternoon from a highway drive they were split between 34 and 34.25 (31 PSI) so I bumped the Procal accordingly. The shift points were "stuck" in 3rd in the 70-75 range so I did a lot of manual shifting between 3rd and 4th, OD was out of the question. I have another highway trip in the AM that should test the new setting, but worse case it's a re-gear in the fall after vacation to 4.10 or 4.56. I may even give AEV a call since it doesn't seem to be the norm for what I am experiencing and have had other oddities.
 
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Yeah 3.21 and I would be leaning toward a regear with 35's. I love my 4.10 with my 35's but would go with 4.88 if I NEEDED to. I would say hilly States and you would greatly benefit from a regear. Kansas and I'd leave it and let the Procal do what it can.
 
seanb33 said:
I have a 2012 automatic unlimited with 35's and 3.21 gears. No problems here! Just get a programmer to set for tire size and you'll be good!
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You really wouldn't notice it much on flat land, but in the hills/mountains and off road you would notice it plenty.:beer:
 
I have a 2012 sport with an auto and 3.21's factory.

I have zero problems running 35's on the 3.21's. It was even fine before I Pro-cal'ed the jeep and even better afterwards.

I live in relatively flat central GA so your geography might play a larger role in the decision. I can burn rubber on my 35's though....:twocents:
 
Heholua said:
You really wouldn't notice it much on flat land, but in the hills/mountains and off road you would notice it plenty.:beer:
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x2 I did notice the low gearing while on a trip to the appalachian mnts. it was noticable but not unbarable in anyway IMO.

I'm not gonna re-gear until I get 37's or bigger.
 
I have a 11' 35s 3.21 Manual it was an Absolute dog! It was fine on flats but I am 100% happy with re-gear to 4.88. Well worth the money. Did it within a month and a half of owning it and 2 weeks after putting on my 35s. Truly best Jeep mod IMO you can do if running bigger tires.
 
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