Jeep Wrangler Forum - Reply to Topic
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > TJ Jeep Wrangler Forum > TJ General Discussion Forum > gear ratio calculator??

Join Wrangler Forum Today


Thread: gear ratio calculator?? Reply to Thread
Title:
  
Message:
Post Icons
You may choose an icon for your message from the following list:
 

Register Now

In order to be able to post messages on the Jeep Wrangler Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Additional Options
Miscellaneous Options

Topic Review (Newest First)
04-06-2012 11:56 AM
Border Dave
Quote:
Originally Posted by Wesboy View Post
I just put 4.10's in my 3 speed auto (on 33's)

Heaps more power - take-off and pick-up much better.
No more constant downshifting in headwinds or steep hills.
Much better offroad - can now tackle steep descents without riding the brakes - it's great to be able to crawl again.

BUT
It's revving its tatas off on the highway.
47mph = 2000RPM
50mph = 2200RPM
60mph = 2700RPM
70mph = 3000RPM
75mph = 3250RPM

With the old stock ratios (3.07's) and 33's, the revs were much lower, but really had to work the accelerator to make progress on the highway. Often had it floored in headwinds or on hills (on the highway) and still struggling to keep up.

Now, with the 4.10's I'm using a LOT less accelerator but revving higher.
It's definitely a compromise with only three speeds.

I have 33s and 3.73 right now, and while first gear is OK, it's definitely lacking any power from a stop, including reverse. You were right in going with 4.10s, unless all you do is drive on the highway.
04-06-2012 11:51 AM
Border Dave
Quote:
Originally Posted by scgeek12 View Post
didnt see the OP said he had an auto lol, I am at 2000 rpms at 60mph with an AX15
Overdrive makes a huge difference.
04-06-2012 04:56 AM
Wesboy I just put 4.10's in my 3 speed auto (on 33's)

Heaps more power - take-off and pick-up much better.
No more constant downshifting in headwinds or steep hills.
Much better offroad - can now tackle steep descents without riding the brakes - it's great to be able to crawl again.

BUT
It's revving its tatas off on the highway.
47mph = 2000RPM
50mph = 2200RPM
60mph = 2700RPM
70mph = 3000RPM
75mph = 3250RPM

With the old stock ratios (3.07's) and 33's, the revs were much lower, but really had to work the accelerator to make progress on the highway. Often had it floored in headwinds or on hills (on the highway) and still struggling to keep up.

Now, with the 4.10's I'm using a LOT less accelerator but revving higher.
04-05-2012 10:26 PM
scgeek12
Quote:
Originally Posted by Border Dave View Post
I used this calculator , and used a tire size of 32.5, since most 33 inch tires are actually smaller, and came up with 47 mph with 4.10s at 2000 rpms. Using 3.73 gear ratio yielded 52 mph at 2000 rpms and 3.07 yielded 63 mph at 2000 rpms.

The question is, "What is your speed now at 2000 rpms?" If you speedometer says around 55 mph, I'd say you probably have 3.73s installed.
didnt see the OP said he had an auto lol, I am at 2000 rpms at 60mph with an AX15
04-05-2012 05:06 PM
Lbailey21 Make sure your speedo gears are right before u throw out RPMs
04-05-2012 04:24 PM
stritt45 that is the same calculator I used. at 55 MPH I was at about 2,000 RPMs, Im gonna have to recheck tomorrow. I have been drinking and right now I can't go driving, haha.
04-05-2012 04:22 PM
Border Dave I used this calculator , and used a tire size of 32.5, since most 33 inch tires are actually smaller, and came up with 47 mph with 4.10s at 2000 rpms. Using 3.73 gear ratio yielded 52 mph at 2000 rpms and 3.07 yielded 63 mph at 2000 rpms.

The question is, "What is your speed now at 2000 rpms?" If you speedometer says around 55 mph, I'd say you probably have 3.73s installed.
04-05-2012 03:29 PM
scgeek12
Quote:
Originally Posted by lbailey21 View Post
if u ready have 4.11s that's awesome but if u don't. Then go 4.56
x2!

and that sounds right, ive got 4.11's and at 60mph im right at 2000rpms
04-05-2012 03:25 PM
Lbailey21 If u ready have 4.11s that's awesome but if u don't. Then go 4.56
04-05-2012 03:23 PM
stritt45
gear ratio calculator??

Hey guys so I have 2000 Jeep 4.0 Automatic. I got it a few months ago and was planning a gear swap, I have a 3 inch lift with 33's. I did a gear calculator and it says I should be at about 2,000 RPM at 55MPH with 4.10 gears does that sound right to you? The reason I ask is I checked the build sheet and it came with 3.07 gears. I would be happy as S*** if the previous owner put in some 4.10 gears. If he put in 4.10's now i gotta check for superior axles. Thanks for the help guys.

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


All times are GMT -5. The time now is 08:14 PM.



Jeep®, Wrangler, Liberty, Wagoneer, Cherokee, and Grand Cherokee are copyrighted and trademarked to Chrysler Motors LLC.
Wranglerforum.com is not in any way associated with the Chrysler Motors LLC