Notices
Modified JK Tech Tech related bulletin board forum regarding subjects such as suspension, tires & wheels, steering, bumpers, skid plates, drive train, cages, on-board air and other useful modifications that will help improve the performance and protection of your Jeep JK Wrangler (Rubicon, Sahara, Unlimited and X) on the trail.

PLEASE DO NOT START SHOW & TELL TYPE THREADS IN THIS FORUM

34 inch tires

Thread Tools
 
Old Dec 23, 2010 | 11:52 AM
  #11  
Venom19's Avatar
JK Enthusiast
 
Joined: Jul 2010
Posts: 176
Likes: 0
From: Andover, NJ
Default

If i don't have a build sheet or window sticker what other way can i tell what gear is in my 2009 X? I bought it used and have no idea...
Reply
Old Dec 23, 2010 | 11:58 AM
  #12  
nthinuf's Avatar
JK Jedi Master
FJOTM Winner
 
Joined: Jan 2008
Posts: 11,463
Likes: 165
From: Austin <--> Colorado Springs
Default

If you are considering 35's, get 35's. (my 315/75/16 bighorns measure 33.5", so don't mess with 33's or 34's)

The only consideration is IF you are going to regear?
Yes. Regardless of when - get the 35's.
No. Get the 35's anyway and live without 6th...
Reply
Old Dec 23, 2010 | 12:39 PM
  #13  
biggreen71's Avatar
JK Newbie
 
Joined: Nov 2009
Posts: 23
Likes: 0
From: Gates,Or
Default

Here ur answer. Click the photo to see the pic correctly.

.4lo.com/calc/geartire.htm[/url]
Attached Thumbnails Click image for larger version

Name:	geartire-formula.gif
Views:	212
Size:	1.9 KB
ID:	111988  

Last edited by mkjeep; Dec 23, 2010 at 02:32 PM. Reason: no clicky
Reply
Old Dec 23, 2010 | 12:47 PM
  #14  
nthinuf's Avatar
JK Jedi Master
FJOTM Winner
 
Joined: Jan 2008
Posts: 11,463
Likes: 165
From: Austin <--> Colorado Springs
Default

Originally Posted by biggreen71
Here ur answer. Click the photo to see the pic correctly.

.4lo.com/calc/geartire.htm[/url]
That is most definitely NOT the answer...


Use the charts in the faq's and read the thousands of posts from people who actually have JKs and run these gears and tires in their JK's. I would be thoroughly pissed off if I spent $1500 and re-geared to the ratio that generic calculator suggested...

Last edited by mkjeep; Dec 23, 2010 at 02:32 PM.
Reply
Old Dec 23, 2010 | 01:09 PM
  #15  
biggreen71's Avatar
JK Newbie
 
Joined: Nov 2009
Posts: 23
Likes: 0
From: Gates,Or
Default

It's a basic calculation, those numbers will get ur gears back to a stock set up, if u read it gives a high side and a low side they say use the low side.. its a tire verses gears which gives u a close recommendation.. so adjust according to tranny difference and planed use.. obviously its not set in stone.. so relaxe turbo

It said 456 for me on 35's I'm goin 488's little lower but still street-able so it was correct.. and that was my original plan anyway. Was just testing it

Last edited by biggreen71; Dec 23, 2010 at 01:15 PM.
Reply
Old Dec 23, 2010 | 01:29 PM
  #16  
biggreen71's Avatar
JK Newbie
 
Joined: Nov 2009
Posts: 23
Likes: 0
From: Gates,Or
Default

So take that number do a little research, adjust to ur needs and go buy.. anyone that would take that number and just go buy shouldn't b messing with modifications
Reply
Old Dec 23, 2010 | 01:50 PM
  #17  
User 122117's Avatar
JK Enthusiast
 
Joined: Sep 2010
Posts: 254
Likes: 0
Default

Originally Posted by Venom19
If i don't have a build sheet or window sticker what other way can i tell what gear is in my 2009 X? I bought it used and have no idea...
http://www.jeep.com/webselfservice/j...m('R')

Go to this page on Jeep's website, click on the Send Us and Email link, and fill out the info. Just tell them you bought it used and you'd like a build sheet. They should get back to you in a few days. It saved me a lot of trouble!
Reply
Old Dec 23, 2010 | 02:26 PM
  #18  
_J__C_'s Avatar
JK Enthusiast
 
Joined: Dec 2009
Posts: 242
Likes: 0
From: Indiana
Default

Originally Posted by bart14
J C, I've asked you about these tires before, but what do these things actually measure, I believe the manufacturer states 34x12.2 Are they anything close to that? Also how far do they stick out past fenders?

Well I would go measure them if I could but I'm out in Virginia for a while. I'll see if there's a tape measure around the hotel, and if so, I'll measure them. As far as sticking out, maybe an inch, and the wheels are 4.5 backspacing.
Reply
Old Dec 23, 2010 | 02:39 PM
  #19  
nthinuf's Avatar
JK Jedi Master
FJOTM Winner
 
Joined: Jan 2008
Posts: 11,463
Likes: 165
From: Austin <--> Colorado Springs
Default

Originally Posted by biggreen71
It's a basic calculation, those numbers will get ur gears back to a stock set up, if u read it gives a high side and a low side they say use the low side.. its a tire verses gears which gives u a close recommendation.. so adjust according to tranny difference and planed use.. obviously its not set in stone.. so relaxe turbo

It said 456 for me on 35's I'm goin 488's little lower but still street-able so it was correct.. and that was my original plan anyway. Was just testing it
Play with it some more. How about stock 3.73's and 32" tires, going to 35's. Pretty common setup, right? It says to go to 4.08. (we'll call it 4.10, which is the stock rubi ratio). Accurate? Not even close. The 'low' gear choice is 4.45. (we'll call it 4.56, since that is available for the JK). Again, is that accurate? Not even close for my unlimited auto.

How about 3.21's and 29" tires, going to 35's? It recommends 3.87, and a low of 4.22. Accurate? Nope. The only JK it is remotely close to is a 'manual' rubicon. So should auto rubi's and any other gear/tire combination spend their money based on that info?

That is a generic calculator that has absolutely nothing to do with the engine or transmissions on the JK...
Reply
Old Dec 23, 2010 | 02:44 PM
  #20  
Crasher's Avatar
JK Enthusiast
 
Joined: Feb 2010
Posts: 422
Likes: 0
From: Plover, WI & Benson, AZ
Default

Originally Posted by jerseyjkredneck
I know abunch of people who run 35's without regearing and just throw a programmer on it with a cold air intake and it runs fine. Its obviuosly a little more sluggish than factory but barely noticeable
Most of them say it works fine because they haven't run a regeared JK. As others have said once you add 35" tires, 513 gears is the best improvement to performance you can do. The CAIs, etc are a waste of money. A programer helps get the most out of the gear change.

You have to ask yourself why those who haven't regeared say it isn't needed, and why none of those who have regeared regret doing it. My JKU with auto is more responsive and better performing with 35s, 513 gears, and Superchip than it was when stock. I wouldn't have kept it in stock form. Now I look forward to driving it.
Reply



All times are GMT -8. The time now is 10:47 PM.