In general 37 inch tires 07 to 11 automatic 4 door

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wiseguy127

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Been doing as much reading as I can and looking at charts. I'm sure its gonna ask. Building a pr44 with 5.13 gears. Would go up to 5.38 but from what I have read. It's not worth is cause pron to break. So what do you guys say?
 
I'm more worried about power, road trip to moab threw Denver from Chicago over the mountains and smiles per gallon?
 
wiseguy127 said:
I'm more worried about power, road trip to moab threw Denver from Chicago over the mountains and smiles per gallon?
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Since you're just passing through I would strongly suggest 5:13's. The pinion is larger than on the 5:38 and your Jeep will do just fine going through the mountains. Granted it's gonna
run out of steam on some of the mountain passes and be pulling some pretty high RPM's, but I went through it with 4 people in mine and a shit ton of gear (3 women :crazyeyes:) so I wouldn't sweat it. My temp gauge never went over the 3/4 mark.

As far as the guys living out there and dealing with those elevations on a daily basis, I'll let them answer that one.
 
I have a 2010 JKU AT on 37s and 5.13s. It does ok around town and works very well off-road. It’s a dog on the freeway. In theory 5.38s are the better choice for this combo, but the pinion gear is tiny and the gear set will be weak because of it.


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I had the same combo for awhile. My opinion it was good enough. Mountain passes were ok until I really started to load down the Jeep with gear and people. Went with 5.13s to not sacrifice pinion size as stated before by others. No regrets. Averaged 13-14 MPG in town. 16-18 on the highway.


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Thank you guys for all your opinions and comments. Makes me feel better about going that route. Now just time to get the pr44
 
I installed 5:38's in my 3.8L about 2 years ago and have done some good trails (Rubicon, KOH Trails, ect.) Without any problems. 2600 RPM at 75 MPH. ORE suggested them when I asked for 5:13's

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WOW off road evolution suggested them over 5.13. I got so confused sometimes on things like this. One person says yes others say no. With ore saying yes really makes me wounder. Then you did those trails with no problems. So is it just long term possible problems for 5.38 or just stress?
 
wiseguy127 said:
WOW off road evolution suggested them over 5.13. I got so confused sometimes on things like this. One person says yes others say no. With ore saying yes really makes me wounder. Then you did those trails with no problems. So is it just long term possible problems for 5.38 or just stress?
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I'm no expert, I walked in to ORE and because of everything I read I asked for 5:13's. They told me if I had the 3.6 then 5:13 is the way to go. But, with the 3.8, he'd recommend 5:38. They really didn't seemed to concerned about offroad durability. Maybe give them a call.

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I put 5.38's in my D60 front and D44 rear (using wheel adapters for now). I know I'm tempting fate a little with the rear right now, but I expect I'll replace it in a couple years. Hopefully it'll live that long if I go easy on it...

The 5.38's have been very nice for daily living near Denver. It's still a dog on mountain passes, so it's not like the 5.13-5.38 jump is a night and day difference. If you're concerned about the strength (which is a reasonable), then I'd stick with the 5.13's. I think you'd be fine in Chicago with 5.13's so long as you can deal with a relatively small difference on mountain passes a couple times per year.

BTW, I have an 09 with an auto.

EDIT: Both shops that I talked with in Denver strongly recommended the 5.38's in Denver with the 3.8l + auto. I also got advice when ordering through Fusion 4x4. The odds that the 5.38's will break are substantially higher than for the 5.13's. However, the odds are still *relatively* low. How hard will you wheel it? How bad would you feel if you're the guy that blows a set of gears on a trail and makes everyone wait/help? I plan on nursing the D44 along on less gnarly trails until I can replace it. I don't want to be that guy :(
 
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I have an 07 auto and 37s. I went with 5.13 just for a little more peace of mind on the trails. Sure, it’s a dog on freeway mountain passes but I doubt 5.38 is going to make a huge difference. If you are after power, you need to look at V8 options.


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Well I was drinking a few beers and decided to call off road evolution and they do actually say to install 5.38 witch shocked me. I guess it's just a chance people take when they install 5.38 vs 5.13 cause I really would hate to have to limp the jeep home cause I broke a gear.
 
wiseguy127 said:
Well I was drinking a few beers and decided to call off road evolution .....
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This is the best way to make purchase decisions to build a Jeep. You can build some really cool shit doing it this way. #beenthere #BuildNowPayLater
 
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