Just had 5:13s installed yesterday on the advice of a very reputable New England Jeep custom shop. Originally wanted to go with 4:56 or 4:88 from what I'd read here and elsewhere but I take this shops opinion over forum guys usually. Not sure I made the right choice this time! Maybe it's a break in period but first impressions are it's wound WAY too tight and also hit 3200 rpm at 75mph. My rig is fairly heavy with toyo 35s, arb front and rear, full size spare, winch, armor, etc. Anyone else on here have 5:13s with the 3.6 and 35s and have any opinion?

 

5.13's are a bit big for 35's. I have them in my 2011 JKU with 35's but I know my next set of tires will be 37's.

Guess it is time for some 37's.

Shop advice is good to some point and Forum advice is good. Best advice at lest for me is putting both together to find the best choice.

R/
Will

 

That would have been the right gear if you had the older 3.8. I agree with post above your best remedy at this point is a set of 37's, which isn't a bad problem to have lol

 

Unfortunately this time you should have taken advice from the forum guys. If you are at 3200Rpm with 35" Toyos even going to a 37" will only bring that down to a couple hundred rpm ... If you are happy with 35" and routinely go 75mph I would have the shop replace the 5.13 with 4.56. Bad call on their part.

I just checked the gearing chart and at 70mph with 5.13/35 you should be at 2862rpm. What you quote is closer to 5.38/35 combo.

5.13 and 5.38 are for the 3.8 crowd. See following 2012 70mph gearing chart.

 

Yup. 5.13 is too high for 35's. Especially if you routinely drive at highway speeds. It has nothing to do with the break in period.

 

I guess I'm just surprised I got such a bad recommendation from a Jeep shop owned by an avid and long time Jeeper. The shop also has a stellar reputation across New England and lots of guys on here know and respect them. I've trusted their opinion for many years and they've never steered me wrong. Hopefully will give me a deal on another swap. Anyone interested in some practically new Yukon 5:13s?? :-)

 

If you went to Route 4 Motors or Steves Jeep Country. I can see why they would recommend 5.13's those guys are hardcore Jeepers that hit some crazy private land trails and some almost un passable class 6 roads up in the Littleton area. In their eyes 5.13's are what you need to do hill climbing and ledge crawling. I went 4.56 and 37's and Now I feel like I should have gone higher especially with my non Rubi T case.

Its all relative to what you are doing I think you should have been more specific on what you wanted to do with your Jeep. But I could be wrong. I think they are a great bunch of guys. My Parents are from Northwood so I grew up in that Area.

 

Me, 5.13's, 3.6L and small 35's (KM2's)
I love the combo, but, I do wheel challenging terrain.
When I was driving 130 miles a day to work and back (for about 8 months, then my company gave me a truck, otherwise the Jeep would still be my DD) it never bothered me to run along at 3100-3200rpm (75mph posted speed limits)
I don't recall exactly, but I believe I routinely got mid/low 18's for mpg (I guess I could search my own posts).

 

I don't think I'm crazy but I swear that after a few days the engine or something has caught up with the new gearing. And yes I used a procal right away. 4 days later it feels more responsive and smoother than day one. It's actually quite the torque hog. RPMs haven't changed but like others have said, this prompts the 37s....

 

I run 5:13's with 35s on my 15 with a manual.
I also live around lots of mountians so it works great for my area.
I just cruise the interstate in the granny lane at 70 mph at about 2900rpm.
Still get around 17mpg. But i actually enjoy driving the jeep up and down the mtns now.
Should be a little better when I go 37s.

On my 07 auto I had 5:38s with 37's and I still felt it wasn't good enough out here so with my 15 I took a chance and for me I think it's a great combo.
If I was gonna drive across the U.S I would probably have to throw some 40s on it....