ive finally saved up enough money to put a lift and a good set of 35's on my jk(hard to do as a college student). i currently have the stock 3.21 gears and have run into a chart on quadratecs website about gear ratio and performance/mpg. how have you guys that have regeared running 35's seen changes? what gears did you change to, how did that affect performance and mpg?

Also, when regearing, do you have to regear both axles? i assume you would but am new to the whole gearhead side of the house. any information would be helpful and much appreciated.

 

You will have to re-gear both axels because if you dont the axels would be fighting each other. Re-gearing is not a cheap proposition, it cost me $1000 to re-gear from 4.10's to 5.13's but if you are increasing your tire size, I think most would agree that a re-gear would be benificial to regain lost performance.

MPG in JK's is never gonna be great but I think you will see a decent and noticable performance boost if you re-gear correctly.

Since you have 3.21's you will have to get a new carrier for your gears as well because 4.10's and lower wont fit on a 3.21 carrier. This will add additional cost to your re-gear. Be sure you do your research on a good shop prior to the re-gear, a shitty install can cause some serious and costly damage. Hope this helps, continue to ask questions, we are more than happy to help. You might also wanna check out the search function on here and see if you can find some more opnions.

 

Future Marine Lt huh? Good luck with that! Im a Marine Sgt.

 

The gear chart at Quadratec is pretty much useless as it uses the 1:1 gear ratio and doesn't accomodate for overdrive and how the two different transmissions function.

If you have an automatic transmission, 35s just aren't going to perform well even with OD off. A manual transmission and you'll at least be able to function until you save up for your gears.

 

X2 on JPop's post

 

good info. thanks on the heads up about the 3.21 not being able to accept 4.10's and larger. its info like that that you need to know prior to going to a shop and having work done. that way you dont get screwed around and know what questions to ask about the install.

jk0311- yea once i finish my degree in 2 years i will get my butter bars. im prior enlisted Navy, but spent my time with the Corps and decided thats where i belong. just have to knock out that degree and finish my other half of OCS.

 

Right on bro, good luck to you! Were you a corpsman? I suggest you go infantry, but thats just me lol. OCS is not too easy but Im sure you will do well. Look me up when you get to the fleet man, Ill be around! PM me if you have any other questions bro.

Stu

 

With 3.21's, the front carrier only requires replacement to a 3.73 and higher ratio unit in order to accommodate a higher gear ratio. You can retain and reuse the rear Dana 44 carrier with any JK 3.73 and higher ratio, no need to replace the rear unless you wish to.

 

If you've got 3.21's and are thinking about dropping 1000+ into that axle you might want to consider Dynatrac Pro-rock 44's. Direct drop in replacement for $2000 (not including install, and maybe a little more for your gearing of choice) is the best option IMO. And you'll have a left over axle assembly for parts when the need arises.

 

I second that!
If you have the dough, spend it on the pro-rock 44s!