Speedo Gear....? - Off-Road Forums & Discussion Groups
Jeep-Short Wheelbase All discussion of short wheelbase Jeeps: CJ, TJ, YJ and JK

LinkBack Thread Tools Display Modes
post #1 of (permalink) Old 02-14-2002, 03:14 PM
Posts: n/a
Speedo Gear....?

Hey guys,
Anyone of you guys know where to buy speedo gears from? Also, does anyone know how to figure out what gear you need, I know there is a formula for it but I can't find! I have 35's, 4.56, and auto tranny. Thanks Jake

Sponsored Links
post #2 of (permalink) Old 02-14-2002, 03:36 PM
Keyboard Implanted
Join Date: Aug 2001
Location: Vermont
Posts: 2,348
Thanks: 0
Thanked 0 Times in 0 Posts
Re: Speedo Gear....?

I think that if you call a dealership they will be able to get you the size of the gear you need, and I think that they can get the actual gear also. However, you need to find a dealership that has people who know what they are doing. Some don't. (I hate when someone who has no idea what they are talking about tries to tell me somthing that I know is not correct, but they think that because they work for a dealership, that makes them right all the time)

91 YJ 4in lift waiting in the garage till March !
"It takes a special type of person to drink a cup of coffee in a jeep"
Olin18 is offline  
post #3 of (permalink) Old 02-14-2002, 06:00 PM
Join Date: Nov 2000
Posts: 2,687
Thanks: 0
Thanked 0 Times in 0 Posts
Re: Speedo Gear....?

Don't use a formula. Your 35" tires are not actually 35" tall and other inaccuracies. You want it closer than that. Simply measure your speed or distance accurately and compare to your odometer or speedometer. If your speedometer is reading high, because you installed numerically higher gears, you need a larger speedometer gear to slow it down. Count the number of teeth on your present gear, and proportion it up (slow the speedo reading down) or down (increase speedo reading) based on the ratio of your current readings to the actual readings. For instance, Your speedo reads 60 but you are actually going 70 because you installed 35" tires. You need to speed it up by installing a smaller speed drive gear. multiply the number of teeth on your present gear by 60/70. You can get the gears from chrysler dealorships. If it was the other way around, the speedo reads too high (you just installed 4.88 gears) then you need a larger speedo gear by 70/60 times the number of teeth on the present gear.

On the other hand, the chart may be right, but at say $20.00 a pop.... your choice.

84 CJ7, 258, HEI, M/C 2100 carb, 5 inch lift, RS9000's, 33x12.5 BFG M/T's, 4.56's and Detroit softlocker, full cage & belts, Xenon flares, Dana 44 rear, GM dual diaphragm brake booster
TiminMb is offline  
Sponsored Links

Quick Reply

Register Now

In order to be able to post messages on the Off-Road Forums & Discussion Groups forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Posting Rules  
You may not post new threads
You may not 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
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome