Jeep Garage  - Jeep Forum banner

Gearing for 37s?

5K views 15 replies 6 participants last post by  OB Mike 
#1 ·
I have ordered a 2015 JKURX (Hard Rock) with 4.10 gears and an auto trans. Is anyone running 37s with 4.10s? I have a buddy with 4.88 in his 2014 and say's they work well. I just was wondering what I could get away with and it still get me around without problems. lol
 
#2 ·
late reply, but wanted to share my thoughts.if you look at the most common tire and gear
chart for 2012 and up JK/JKU, for your set up,
you are only off roughly
250 rpm from stock. of course heavier tires
and bumpers, sliders etc. make a diff.
and will take away (some!) grunt on the
street. off road I think your fine.
410s, auto, JKU and 37's can be done.
in fact I am running 37's with auto 410s
with the old 3.8 motor. I leave OD off
always!! 3.8 is happy at 26 to 29 rpm
so she stays in third all the time.
I do have a 2 door and run the MTRK
as it is a very light full size 37.
my 410s and my 37s may very well end
up on a 2015 JKU auto.
$ave and use the extra ca$h for other mods!
 
#3 ·
Thanks for the reply. I was looking at the same tires but have read a lot of mixed reviews. It was mainly with balancing and some tread life issues which was probably a result of the balancing. What is your experiance with the MTRK's? Sounds like you like them.
 
#6 ·
I think you could be happy with the 4.10 and 37 but if you want it closer to stock I would go 4.88. Make sure you have the AEV Procal or other programmer when you swap out gears or you will throw your Jeep into limp mode.
 
#7 ·
I have heard the term limp mode a couple of times on these forms. I assume it has to do with the computer and shutting down your vehicle and not just running like a dog because your gears and tire size are not a good match for each other. I do not have much experiance in this area since all of my other Jeeps were CJs w/ V8s and balls. Or classic Broncos with V8s. This is my first newer off road vehicle and I want to do it right since I will probably not get another new vehicle again. lol
 
#8 ·
I'm torn between 35's & 37's.
I'll be looking for the Rubicon Express 4.5" short arm lift prior to taking delivery as well as upgraded shoes.
I had a stock 14 Rubi before and was really impressed w the power.
Definitely not my daily driver, but will see roads.
Thoughts?
 
#9 ·
I'm in the same boat. I have a 2015 Rubi Hard Rock coming in before long. I am juggling between 35 and 37s. I may get a more street friendly set of 35s and change out to 37s for the trail runs. I was looking at the Rubicon Xpress lifts also. I think I'm going with Metal Cloak though. I have not found many bad comments about them and I've looked a lot. I'll be rolling with the 410 gears to start but I think I'll end up doing 488 based off one of my buddies build.
 
#10 ·
I did it.
Getting the RE 4.5", Pro-Comp 7036's, Pro-Comp 37x12.5x17s, new drive shafts, & Smittybilt Rock Gaurds
I was told by somebody who wheels for a living that 37's, 4:10s, and the current 3.6L engine won't lose much acceleration.
He's also the guy who does the installs for local dealers.
It wouldn't have effected him if I'd chosen 35's.
I'll let you know how it works out.


Sent from my iPhone using JeepGarage
 
#11 ·
Great. let me know. I am in D1 Status on my JKUR HR. I have my Metal Cloak in route. I also went with the 4.10 and an auto trans. Still Juggling the 35 vs 37. I'm thinking 35s in a good all terrain for daily and maybe pick up some 37s and rotate out for trail runs. That's a pricey way to do things though.
 
#12 ·
If it's your DD, I'd suggest a good set of A/T in 35s
Both the Pro-Comps & BFGs have pretty good wear
I'm selling my stock Rubis ASAP


Sent from my iPhone using JeepGarage
 
#14 ·
My dealer sells many Rubis w 35's pre-loaded.
I had so much confidence in the power of my 2014 w 33's that I went ahead and got mine built w 37's.
I haven't seen it yet, and it also isn't my DD.
 
#16 ·
Almost done, but still haven't driven it yet.
Land vehicle Vehicle Automotive tire Car Tire
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top