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I have always been a car driver, so I have no experience with wheeling. So I need some advice please. I just bought a 2014 JK Sport S (3.6L Automatic) with factory 255/75R17 tires BUT i just discovered that it has a 3.21 axle ratio. From all the reading I have been doing, it appears that this is a useless set up. I plan on using this JK as my DD as well as getting into wheeling. Since I have never taken a vehicle off road, I don't know how, exactly I will be using it. I'm also on a limited budget and had planed on making mods over time. So, getting started what do i need to do first?

My thought is, that I would get it re-geared first. Since the cost is going to be the same for whatever axle ratio I select, is it best to go ahead and get a 5.13 ratio even though I have 32 inch tires? My understanding is that if I go to 35's there are all kinds of things, in addition to re-gearing, that I will need to do.

Is it possible to do any kind of wheeling with a 3.21 and 32" Goodyear Wrangler SR-A tires?
 

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You don't want 5.13 gears with 32" tires, your rpms will be screaming on the highway!!..You don't want 5.13's with the 3.6v6 automatic and 35's, you'll still be way over geared. 4.56 gears are the perfect match with the 3.6 and automatic tranny and 35" tires.

Your 3.21 gears are fine until you decide to move up in tire size. I have the factory optional 3.73 gears with 33" tires and it's a perfect combination.

You would only need 5.13 gears if you were running 37" tires with the manual tranny.
 

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I just regeared to 4.56 from 3.21 this past Monday. I currently have 33's but plan on getting 35's in the near future.

Coming from 3.21 off-roading, I would say that while it does help you crawl over obstacles a lot better, I wouldn't go higher than 4.56. Your jeep is still very capable as it is now and honestly you can wheel 3.21, although there is no doubt that you will get better performance with a lower gear setup. There's many different preferences to wheeling; pick which one suites you before you change your rig. Doing it the other way around is how you end up spending money on the same category of upgrade twice. Trust me I know :/
 

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Is it possible to do any kind of wheeling with a 3.21 and 32" Goodyear Wrangler SR-A tires?
We took a 2013 with a 2.5 lift 33x12.50x15 duratracs running 3.21 gears to the polo duro Jeep jamboree, Hot Springs (formerly Superlift) many other off road parks, deer leases, pulled 3000 lb trailers through the hill country, put 55K miles on it. Have went places where much heftier built rigs have been stuck and could not seem to climb...on and on. Yes I have pictures....The JK in the shot is a rubicon with a 3.5 Metalcloak gamechanger (lots of money) driver not so much, running up "Daves Crack" a challange at Polo Duro ....this was right after we made the same run with those useless 3.21s and even worse ....... those horrible unlocked open difs which are also useless if you read enough internet......

If you have 3.21s and convince yourself or let someone else convince you it's a useless rig, then it's useless. And I'm more than willing to bet that your Jeep will do more than you are willing to attempt....
 

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I have always been a car driver, so I have no experience with wheeling. So I need some advice please. I just bought a 2014 JK Sport S (3.6L Automatic) with factory 255/75R17 tires BUT i just discovered that it has a 3.21 axle ratio. From all the reading I have been doing, it appears that this is a useless set up. I plan on using this JK as my DD as well as getting into wheeling. Since I have never taken a vehicle off road, I don't know how, exactly I will be using it. I'm also on a limited budget and had planed on making mods over time. So, getting started what do i need to do first?

My thought is, that I would get it re-geared first. Since the cost is going to be the same for whatever axle ratio I select, is it best to go ahead and get a 5.13 ratio even though I have 32 inch tires? My understanding is that if I go to 35's there are all kinds of things, in addition to re-gearing, that I will need to do.

Is it possible to do any kind of wheeling with a 3.21 and 32" Goodyear Wrangler SR-A tires?
I have ran 35's on my 2010 JKU with 3:73 gears for two years and About 45,000 miles and I have not had any issues out of mine. If you add a B&G transmission cooler, and buy a superchips flashpaqs that's about all you will need other than a lift and wheel spacers if yours aren't 17x9 wheels or buy 17x9 wheels. I have spacers and 17x9 wheels on mine to give it a nice wide stance with a 3" suspension and 1.25" body lift. I would probably regear to 4:88 if I went up to a 37 and only go to 5:13 if I decide to run 40's. Anything over a 37 you will want to regear but you can ride nicely on 35's if you do the above stuff I mentioned.



**edit** mine has never let me down in any situation I have been in and it didn't when i ran the stock 32" BFGs either.
 

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I have always been a car driver, so I have no experience with wheeling. So I need some advice please. I just bought a 2014 JK Sport S (3.6L Automatic) with factory 255/75R17 tires BUT i just discovered that it has a 3.21 axle ratio. From all the reading I have been doing, it appears that this is a useless set up. I plan on using this JK as my DD as well as getting into wheeling. Since I have never taken a vehicle off road, I don't know how, exactly I will be using it. I'm also on a limited budget and had planed on making mods over time. So, getting started what do i need to do first?

My thought is, that I would get it re-geared first. Since the cost is going to be the same for whatever axle ratio I select, is it best to go ahead and get a 5.13 ratio even though I have 32 inch tires? My understanding is that if I go to 35's there are all kinds of things, in addition to re-gearing, that I will need to do.

Is it possible to do any kind of wheeling with a 3.21 and 32" Goodyear Wrangler SR-A tires?
3.21 with stock tires delivers fabulous gas mileage.
5.13..... stock tires.... wear ear plugs on the highway and expect about 15 mpg.

Go here first...

http://www.grimmjeeper.com/gears.html

I'd just get 33 ATs tires, for DD and good gas milage or 33MTs for better traction off road but they will wear out faster than ATs. And yes... going to 35s adds stress to every driveline component. At some point stock things will start to break. But before buying 5.13s.... do some off roading. 4.10, 4.56, 4.88 might be a better choice. WAIT till you know what you really want/need.
 

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We took a 2013 with a 2.5 lift 33x12.50x15 duratracs running 3.21 gears to the polo duro Jeep jamboree, Hot Springs (formerly Superlift) many other off road parks, deer leases, pulled 3000 lb trailers through the hill country, put 55K miles on it. Have went places where much heftier built rigs have been stuck and could not seem to climb...on and on. Yes I have pictures....The JK in the shot is a rubicon with a 3.5 Metalcloak gamechanger (lots of money) driver not so much, running up "Daves Crack" a challange at Polo Duro ....this was right after we made the same run with those useless 3.21s and even worse ....... those horrible unlocked open difs which are also useless if you read enough internet......

If you have 3.21s and convince yourself or let someone else convince you it's a useless rig, then it's useless. And I'm more than willing to bet that your Jeep will do more than you are willing to attempt....
100% !!!! If you know how to drive you do not need to change every component to have fun. I love having the Jeep everyone laughs at.... then show them up. Way more fun than getting beat after spending $35K modifying yer Jeep to be a SEMA show stopper.
 

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I would highly recommend doing a lift and tires first, then change gearing if you can't live with the current gearing setup. But 3.21 and 33's will be fine. Spend your hard earned money elsewhere first.
 

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Aim for the green area on this chart. If you plan to stay stock size tires, I would regear now if it were me. If you plan to eventually run larger tires, wait until you get them to regear.
 

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2 door will be more bearable with 3.21, IMO put that $ in the bank and wait until it's time for tires. In the meantime take your new Jeep out and wheel the crap out of it :D

Here was my first trip in our stock '13 with SRA tires.





 

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Aim for the green area on this chart. If you plan to stay stock size tires, I would regear now if it were me. If you plan to eventually run larger tires, wait until you get them to regear.
I've been wondering if a regearing would make daily driving a bit better with my Freedom and 33" tires? I don't plan on doing much off roading and this chart seems to indicate that a 3.73 would be better for DD with my 33" combination, if I'm reading this correctly?
 

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Not used to seeing a white Jeep BBS...lol.

I have 3.21's and open diffs and 35's. While not ideal, it gets the job done for now. Not that I have done anything crazy, and he took it easy on me but I kept up with @Bluebabysoundin the same stuff pictured above(in what looks like the same conditions)
 

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YEP, useless 3.21 on axle breaking 35s with only 2.5" of lift and open diffs right here.

My advice to you is disconnect your swaybars and take it offroad. Then you can pick what you need for your driving style and your jeep.
 

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I suggest you don't make any changes based on "all the reading you are doing" but instead make changes based on all the wheeling you have done and what you found out you need based on that experience. Find out how to drive by wheeling with some experienced folks or take a hands on driving course (make sure it isn't just some classroom course but one that is taught on the trails with you practicing the techniques).


Sent from my iPhone using Tapatalk
 

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Discussion Starter #16
Thanks everyone, for all the great information!

Thanks for all the helpful information that everyone presented. Especially those who have first hand experience running a 3.21. I am definitely feeling better about my situation.
 

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I've been wondering if a regearing would make daily driving a bit better with my Freedom and 33" tires? I don't plan on doing much off roading and this chart seems to indicate that a 3.73 would be better for DD with my 33" combination, if I'm reading this correctly?
I run the factory optional 3.73 gears with 33" tires. My tires measure 32" at 30 psi mounted on my Jeep. This puts me right in the green area of the gear chart and I get use out all 6 of my manual gears. IMO it's the perferct gear choice for 33's as it gives a great balance between on and off road driving.

Now the hard part. You don't want to pay the amount of money that a regear cost just to go from 3.21's to 3.73's so if you stay with a 33" tire I would just run your 3.21's and call it a day. If however you decide to go up to a 35" tire then you could do 4.56 gears which would be worth the cost jumping from a 3.21 to 4.56.
 

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35's and 3.21's here, sure it will do awesome with 4.56's, but i haven't being able to afford the damn regearing yet, Cool thing i'm not running king of the hammers though, i'm a few skids, dual lockers, front 44 and gears away from it :), but she'll go almost anwyhere else with 35's and 3.21's, sure 3.21 not the right gearing, and i hope to have the gears corrected in a couple of months down the road.

In the meantime, i'll still take her out and have fun with it, this hill doesn't do justice in this video, and i'm barely stepping on the gas here with the 3.21's, asides from being super easy on my equipment anyways as i don't have gussets or ball joints yet, (i'm having this fixed next week), i think gussets and the BJ's are needed first with 35's, again, at least for the type of wheeling i do.

http://www.youtube.com/watch?v=PAT-aaiwxF8

I'm planning to run the John Bull trail in Big Bear Cali with 3.21's in about 4 weeks, http://www.wranglerforum.com/f55/2016-national-go-topless-day-saturday-may-14th-with-socal-canyon-krawlers-1679393.html


http://www.youtube.com/watch?v=nCt507fxAK8
 

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Aim for the green area on this chart. If you plan to stay stock size tires, I would regear now if it were me. If you plan to eventually run larger tires, wait until you get them to regear.
That chart is not gospel, trust me. I just regeared my Jeep to 4.56 based on that chart. For my Jeep it is about 200 RPM higher than listed at 70MPH, (by GPS). Even with the Flashpaq, my speedo is about 2MPH off at 70.

I know now that 4.10 would have been perfect for my setup, and offered me better gas mileage on the highway.

I'm not unhappy with the 4.56 by any means, I just could have done it a little different and had the perfect set up for my needs.
 

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That chart is not gospel, trust me. I just regeared my Jeep to 4.56 based on that chart. For my Jeep it is about 200 RPM higher than listed at 70MPH, (by GPS). Even with the Flashpaq, my speedo is about 2MPH off at 70.

I know now that 4.10 would have been perfect for my setup, and offered me better gas mileage on the highway.

I'm not unhappy with the 4.56 by any means, I just could have done it a little different and had the perfect set up for my needs.

Are you going by ACTUAL height or advertised height? For instance most 35" tires are actually 34.? and measure on the vehicle, under load, as low as 33 something.

Just curious.
 
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