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

What gears are the best

Thread Tools
 
Old Oct 24, 2011 | 06:13 PM
  #1  
Zenabi's Avatar
Thread Starter
JK Enthusiast
 
Joined: Sep 2011
Posts: 185
Likes: 0
From: Houma, Louisiana
Default What gears are the best

I am about to put 35's on my jk an was wondering what would be the best gears for an everyday driver an able to handle the 35's ( my jk is a manual )
Reply
Old Oct 24, 2011 | 06:24 PM
  #2  
Zenabi's Avatar
Thread Starter
JK Enthusiast
 
Joined: Sep 2011
Posts: 185
Likes: 0
From: Houma, Louisiana
Default

Will the 4.88's be good for highway too?
Reply
Old Oct 24, 2011 | 06:32 PM
  #3  
mmcc's Avatar
JK Enthusiast
 
Joined: Dec 2010
Posts: 185
Likes: 0
From: Hanover, NJ
Default

I like them on highway runs... I just did Yukon 4.88s with my 35 nittos automatic and am very happy with overall performance... If I were using it more off road related may have went 5:13s.... But everyone will have there own option.
Reply
Old Oct 24, 2011 | 07:01 PM
  #4  
dglenn's Avatar
JK Newbie
 
Joined: Aug 2010
Posts: 73
Likes: 0
From: Oxnard, CA
Default

I have 4.56 and 33s. I am turning about 2800rpm at 70. You will probable be about the same with 4.88 and 35s.
Reply
Old Oct 24, 2011 | 07:22 PM
  #5  
Kevin123's Avatar
JK Enthusiast
 
Joined: Oct 2011
Posts: 191
Likes: 0
From: Childress, Texas
Default

Originally Posted by dglenn
I have 4.56 and 33s. I am turning about 2800rpm at 70. You will probable be about the same with 4.88 and 35s.
I think I'm going to go with 4:56 with 35s and the 6 speed. More suitable for me!
Reply
Old Oct 24, 2011 | 07:39 PM
  #6  
Brandon1024's Avatar
JK Freak
 
Joined: Jan 2011
Posts: 566
Likes: 0
From: Barrington, IL
Default

4.88 would be best plus if you ever want lockers they arent recommended with the 5.13 due to the small pinion
Reply
Old Oct 24, 2011 | 07:51 PM
  #7  
nthinuf's Avatar
JK Jedi Master
FJOTM Winner
 
Joined: Jan 2008
Posts: 11,463
Likes: 165
From: Austin <--> Colorado Springs
Default

There are some faq's at the top of this modified area, check the drivetrain section for a great rpm chart. (use actual measured tire heights, not mfg's spec).

This is a few years old, but there is some good info here, including dyno charts.
https://www.jk-forum.com/forums/show...ire-Size-Chart
Reply
Old Oct 24, 2011 | 07:57 PM
  #8  
mrjayd's Avatar
JK Newbie
 
Joined: Oct 2011
Posts: 57
Likes: 0
From: San Diego, CA
Default I am confused by all these numbers

What's the difference in the low numbers versus high numbers? I just got a new 2011 Sahara Unlimited that came with 3.73 gears. I was planning on getting a Teraflex 3" lift with 35's but I think I will wait on the lift and just get some wider 18 or 20" rims and BFG A/T 33's for now. I don't plan on offroading this thing and will strictly be on the street and freeways. So what's the difference in me having the stock 3.73 gears as opposed to putting on something with a higher number?

Thanks.....JD
Reply
Old Oct 24, 2011 | 08:10 PM
  #9  
nthinuf's Avatar
JK Jedi Master
FJOTM Winner
 
Joined: Jan 2008
Posts: 11,463
Likes: 165
From: Austin <--> Colorado Springs
Default

Originally Posted by mrjayd
What's the difference in the low numbers versus high numbers? I just got a new 2011 Sahara Unlimited that came with 3.73 gears. I was planning on getting a Teraflex 3" lift with 35's but I think I will wait on the lift and just get some wider 18 or 20" rims and BFG A/T 33's for now. I don't plan on offroading this thing and will strictly be on the street and freeways. So what's the difference in me having the stock 3.73 gears as opposed to putting on something with a higher number?

Thanks.....JD
Look at the chart mentioned above.

As an example:

A 6spd with 3.21's and 29" tires will run appx 2188 rpm @ 70mpg
Go up to a 33" tire, and you are at 1923 rpm @ 70. (pretty big performance loss).
Swap your gears to 3.73 with those same 33" tires and your rpm's come up to 2234 @ 70, or a bit better than your stock performance.


An auto with 3.73's and 32" tires = 1892 rpm @ 70.
(many auto owners will complain that this 'stock' setup is underpowered straight from the factory).
3.73 with 35's = 1730 rpm @ 70
5.13 with 35's = 2380rpm @ 70
(many auto owners will tell you that this rpm range is what their JK's should have come with from the factory).


Again, use actual measured tire heights with those charts, not mfg's numbers.

Last edited by nthinuf; Oct 24, 2011 at 08:13 PM.
Reply
Old Oct 24, 2011 | 09:38 PM
  #10  
orfanidisnikolaos's Avatar
JK Enthusiast
 
Joined: Jan 2011
Posts: 309
Likes: 0
From: Athens,Greece
Default

I have my jk in the 4wd shop and getting 4.56 installed. I ram 35s and have a manual. i will let you know which my impression is tomorrow!!!
Reply



All times are GMT -8. The time now is 07:50 PM.