Great thread. Thanks everybody.

13 Rubi, going 35" / 5.13 next with plans of 37" to 40" later. Lot of saving to do,,,

 

Folks,

I am planning on 4:56s and 35s on my 2012 Sahara Auto. Does anyone know of a reputable shop in the southwestern Idaho area? I have been given 2 different quotes so far (both from Jeep dealerships). First was $2900. The second was $2500. I've been told 15 hours for labor alone. Based on 100s of regearing threads, it sounds like the dealerships are trying to put the screws too me. Thanks!

 

If you're just doing gears you should be looking at 8 hours labor. I was quoted 10 hours by two shops and 15 hours by another, but my quote includes compressor install and running air lines for an arb locker. Can't help you with a shop near you but I think that 6-8 hours is pretty standard install time for gears.

 

OK, here is my real world situation. I have a '12 JKU Rubicon with the stock 4.10s and auto. I've been running 37s for almost a year and have been pretty happy with the performance. I realize that MPG drops at higher elevation (I'm at 6500') and I've been fairly consistent at around 15.5 MPG on average. My concerns have been: 1) Even at 75MPH I rarely see fifth gear unless I'm going downhill with a tail wind, 2) I want to have the ability to pull a 2000# trailer in the future, and 3) the engine temp starts to climb as I am trying to stay at the speed limit going up long mountain passes. I'm using the Procal to correct for the tire size.

Last week I pulled the trigger and had 4.88s installed. I'm only a couple hundred miles into it, but to be honest with you I haven't noticed any startling recovery of lost power and my MPGs have dropped to around 14.5 (based on the computer). I also went with new diff covers with higher fill holes. The back is holding up fine, but the front is spewing out fluid thru the breather like crazy as its trying to bring the level down.

Anyone want to add any comments?

 

It sounds like, if you had to do it over you would have went with 5.13's.

 

I dont think i'v seen any one yet address the issue of how heavy we all make our jeeps! Bumpers, wheels/tires, spares, sliders, under armor, air tanks, cages, compressors, gas tanks, tools, jacks,heavy duty control arms and trac bars,, increasingly heavy wives,, my advise for anyone doing a re gear and undecided between 2 ratios,,,, go with the numerically higher ratio!! You will not regret it when you try to get that heavy jeep rolling.

 

You guys are going to be regearing my 13 Rubi. I will be running 40x15.5x20 Toyo Open Country. Would you still go with a 5:13 or move up to a 5:38? I am more interested in performance than milage?

On a side note, coming out of 13 Corvettes and 3 Vipers, gears are the 1ST thing I have always done. Going from 3.07's to 3.55's in the Viper was EPIC!

 

I'm about 2000' above you & just did 5.13's today... and the difference on 35's is UNREAL. The power on road is a big difference, and offroad I don't need the gas pedal anymore. I'm pretty amazed that it feels this much better at elevation. Around here, with 37's I'd go 5.38 for sure, but on my 35's I'm VERY happy with the 5.13's. (I drove home on 70 going about 80 for the first time since I've owned this... it's almost bearable driving on the road, which is pretty cool!)

 

So my question is, how bad is running your motor at 2600+ rpms on the high way for long periods of time. What long term effects will this have on the jeep ?

 

Is running a numerically lower gear (3.21) harder on the driveline? Cutch? With larger tires