Jeep Wrangler Forum - Reply to Topic
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > TJ Jeep Wrangler Forum > TJ Tech Forum > Speedo Gear swap/change.

Join Wrangler Forum Today


Thread: Speedo Gear swap/change. 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)
03-11-2014 08:28 PM
Tiaan Hi guys, I have done everything the thread shows to the T. I am still off by 10 mph fast on my speedometer. I have d44 with 3.73 and 33s so I should run the 31 tooth speedo gear. The tab on the diff cover says it is a 3.73 but iam starting to question that now. Any advice would be greatly appreciated .
01-03-2014 06:09 PM
Sourmash Ok, so I reread the thread and found the ratio. I've got a '97 TJ, Automatic, Running 33" Toyo's, with 3.07 gear ratio. I see on the chart in this thread that it says 26 tooth, my question is almost every other chart I've seen doesn't show a size for the 3.07 and 33" tires, I dont fully understand gear ratios but can someone explain in layman's terms why they wouldn't have one for that combination? Is the 26 tooth the closest I will get to accuracy?
01-03-2014 03:49 PM
Sourmash At the risk of looking like a total idiot, can someone tell me how to confirm the gear ratio?
10-02-2013 05:14 PM
JT42 Ahhhh yeah I bet it is security since I pulled up the page from my work laptop. Appreciate the answer and the reposted picture. Cant wait to get this done. I will order the new gear tonight!
10-02-2013 04:20 PM
distortedtj Here is an attached photo of the ratio line up.

Find the numbers on your speedo falls under "tooth count".
Line them up at the 5 o'clock position of the hole. "also lines up with where the wishbone clamp sets in the plastic housing.

Since you have a 39tooth gear yours should look like this.....
10-02-2013 04:13 PM
distortedtj
Quote:
Originally Posted by JT42 View Post
Wow this is awesome! When I re-geared my Dakota I had to have the dealership do a flash and since they didnt have a chart it was trial and error until we got it right.

Since I have an 03 TJ Sport with 33's and 4.56's I understand I will need a short shaft 39 tooth. My only question is, did the original post intially have pictures to go along with the write-up or was it always just the step-by-step instructions? I am not sure I fully understand the rotation deal and think pics would help me before I tackle this.
There is still pictures with the original posts. If you can not see them try to adjust your security settings. All photos are linked from Photobucket.
10-02-2013 03:18 PM
JT42 Wow this is awesome! When I re-geared my Dakota I had to have the dealership do a flash and since they didnt have a chart it was trial and error until we got it right.

Since I have an 03 TJ Sport with 33's and 4.56's I understand I will need a short shaft 39 tooth. My only question is, did the original post intially have pictures to go along with the write-up or was it always just the step-by-step instructions? I am not sure I fully understand the rotation deal and think pics would help me before I tackle this.
07-23-2013 03:48 PM
InvertChaos
Quote:
Originally Posted by Rewind View Post
Yes it's a TJ.....According to the Vin I have a 3.07 axle ratio.
I would double check the ratio yourself. According to the chart, they don't make a gear small enough for you...

You've got a 34.4" tire http://www.quadratec.com/jeep_knowle...article-46.htm
07-23-2013 03:35 PM
Rewind Yes it's a TJ.....According to the Vin I have a 3.07 axle ratio.
07-23-2013 03:22 PM
InvertChaos
Quote:
Originally Posted by Rewind View Post
How do I tell which speedo gear I need to compensate for the larger tires (315/70-17)
There is a chart floating around somewhere. You have a TJ correct? Also what gears do you have in the diffs?
07-23-2013 03:18 PM
Rewind How do I tell which speedo gear I need to compensate for the larger tires (315/70-17)
07-23-2013 01:43 PM
AlexS put your transfer case in neutral. jack up the rear end of your jeep. Spin your rear tire around once and count the number of times the drive shaft spins. That will roughly tell you what gears you have
07-23-2013 12:22 PM
Rewind
Quote:
Originally Posted by AlexS View Post
Your PO had to have regeared if your running 35s on 3.07. I have 33s on 3.73 and its a bit sluggish!
Maybe not.........I think mine is a bit sluggish too.
07-23-2013 12:03 PM
AlexS
Quote:
Originally Posted by Rewind View Post
Ok, this is interesting........there is no speedo gear tooth count listed for my set up. I have (according to my vin) a 3.07 axle ratio and I'm running 35's. Any ideas on which one I need?
Your PO had to have regeared if your running 35s on 3.07. I have 33s on 3.73 and its a bit sluggish!
07-23-2013 11:15 AM
Rewind Ok, this is interesting........there is no speedo gear tooth count listed for my set up. I have (according to my vin) a 3.07 axle ratio and I'm running 35's. Any ideas on which one I need?
07-20-2013 10:20 PM
RevCo666
Quote:
Originally Posted by distortedtj View Post
Yes Sir.
Thanks for clarifying that! I know running 31's is messing my milage readings but its always better to be accurate non the less. I'll check at parts store for prices since everywhere else seems to want to charge me 25$ for shipping and up for a 40$ part online.
07-20-2013 09:58 PM
distortedtj
Quote:
Originally Posted by RevCo666 View Post
So in my case I'm looking at a short shaft version? 2001 TJ
Yes Sir.
07-20-2013 03:56 PM
RevCo666
Quote:
Originally Posted by distortedtj View Post
Year and model of the T-case.

ALL TJ np231j cases use a short shaft.
All TJ rubicon np241 do NOT use a gear driven speedo. But a tone ring. You must have a dealer reprogram the comp to the correction or use a aftermarket programmer to adjust it yourself. "i'd use the programmer'.
So in my case I'm looking at a short shaft version? 2001 TJ
07-20-2013 01:23 PM
distortedtj
Quote:
Originally Posted by RevCo666 View Post
How does one know if you need a short or long shaft version of a speedo gear??
Year and model of the T-case.

ALL TJ np231j cases use a short shaft.
All TJ rubicon np241 do NOT use a gear driven speedo. But a tone ring. You must have a dealer reprogram the comp to the correction or use a aftermarket programmer to adjust it yourself. "i'd use the programmer'.
07-16-2013 02:05 PM
RevCo666 How does one know if you need a short or long shaft version of a speedo gear??
04-17-2013 12:16 AM
MissingMyYj
Quote:
Originally Posted by MissingMyYj View Post
let's bring back a dead thread....

I just bought a 1993 jeep wrangler with a 4.0l with 35" tires and 4.11 gears. I wondered if my speedo gear was swapped out so I crawled under it and yanked the gear out. Turns out it was changed to a number 35; this doesn't line up with the chart though.



How will this affect my current millage and mpg? Should I swap it for a 34? When I used my gps and compared it to my speedometer I am going 1.11 miles for ever 1 mile shown on the speedo.

Thanks!
Actually i have 4.10 gears in the rear
04-16-2013 10:01 PM
MissingMyYj let's bring back a dead thread....

I just bought a 1993 jeep wrangler with a 4.0l with 35" tires and 4.11 gears. I wondered if my speedo gear was swapped out so I crawled under it and yanked the gear out. Turns out it was changed to a number 35; this doesn't line up with the chart though.



How will this affect my current millage and mpg? Should I swap it for a 34? When I used my gps and compared it to my speedometer I am going 1.11 miles for ever 1 mile shown on the speedo.

Thanks!
03-08-2013 08:56 PM
871kevin Does anyone know if there are numbers on speedos that are cable not electronic? I don't know what to turn it to
02-28-2013 04:47 PM
distortedtj
Quote:
Originally Posted by Sinister6 View Post
So this will NOT work if you have a JK or the RUBICON version of the TJ? Just want to clarify this....I saw it won't work for a JK but seemed to miss the RUBICON...
I have an 06 Rubicon manual transmission...
-EXCELLENT WRITE-UP BTW!
Correct. The Rubicon does NOT use a speedo gear in the t-case tail housing. To correct the speedo with a rubi t-case you will have to purchase a programer to recal it or have a dealer reflash the computer to correct it.

"Tru-speed" I believe it is called made by superlift is a decent speedo recalculator.
02-28-2013 03:32 PM
Sinister6 [QUOTE=distortedtj;2615886]As noted before. The Rubicon 241 t-case uses a tone ring. You can only fix the speedo with a computer flash or programmer that has the option to adjust the speedo gear for tire size.



So this will NOT work if you have a JK or the RUBICON version of the TJ? Just want to clarify this....I saw it won't work for a JK but seemed to miss the RUBICON...
I have an 06 Rubicon manual transmission...


-EXCELLENT WRITE-UP BTW!
02-19-2013 07:31 PM
distortedtj
Quote:
Originally Posted by Godric View Post
This post is super helpful, the only way to make it easier is for you to do it for me!
Sorry, gas to IA would kill my jeep money.
02-19-2013 07:07 PM
Godric This post is super helpful, the only way to make it easier is for you to do it for me!
01-29-2013 10:35 PM
distortedtj
Quote:
Originally Posted by hickdubious View Post
Will replacing the speedo gear help increase MPG?
The speedo gear only is there to tell you your true speed. Swapping it out will absolutely not increase your MPG's, but it will tell you your real MPG's.

Without swapping the gear you are not getting a correct MPG reading on your Odometer.
01-29-2013 03:51 PM
Quest4life Awesome post. I know for a fact I would have missed the gear number on the housing! Thanks i am sure you saved me time and anguish!
01-29-2013 03:46 PM
hickdubious Will replacing the speedo gear help increase MPG?
This thread has more than 30 replies. Click here to review the whole thread.

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 01:07 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