I have a 2010 2dr auto w/ 3.73 gears. I was recently driving down the highway and the rpms were aroud 3500 anytime I had any incline. I am running a 31" tire and will be going to to 33's. I do tow evey now and then. I plan on going to 4.56's. Will that keep my rpm's lower? If it wasn't 15 degrees out I would have over heated my trans again. I plan on getting a trans coler but I dont want my rpms that high every time I run I down the highway. I considering trading her in for a 2012 but if the gears work I would rather go that route.

 

How fast we're you going to turn 3500 RPMS? My set up I run on my 2010 JKU I have 12.50/17/35 MTR witch KEVELAR on a aftermarket wheel 4.5" back spacing , they measure 34.5 mounted. Gears are 5:13 Yukon and I have a Superchip tuner to take care of the speedo , trans running the 87 Octang tune. At 70 mph I run around 2250 rpm.

 

I'm running the superchips as well all dialed in. They would hit 3500 anytime there was a hill. Probly somewhere between 70-80 mph. The thing is that ive had this setup for a while and never had this issue. I could do 60 mph up a small hill and it would hit 3500. Just doesnt make sense.

 

With the low price tag, a trans cooler should be considered a must-have.

For the gears, open the faq's and plug the numbers in. Using actual measured tire heights will give different numbers, but this should be a good ballpark example.

auto, 3.73, 31" =
1953 rpm @ 70

on the hills, you were shifting down to 3rd
1953 / .69 =
2830 rpm @ 70

(3500 ? Guessing you were dropping down to 2nd?)

auto, 4.56, 33" =
2243 rpm @ 70

you will stay in OD longer, but when you downshift
2243 / .69 =
3250 rpm @ 70


auto, 5.13, 33" =
2524 rpm @ 70
Very popular ratio for anyone going over stock tire sizes, and the mid 2k's seem to be a good place to run this engine. Gives enough hp/torque to keep you in OD for the hills and crosswinds.

 

Thanks nthinuf for the help. Looks like reagearing should help a little. THe whole 3500 is just crazy anytime I need to run down the highway.