Speedo gear

[Muncher]

Can some tell me what tooth count I need for a speedo gear in my transfer case? I have a 87 5 speed if that helps at all

[87MJTIM]

You need the diff. gear ratio and tire size to determine the tooth count.

 

Search the internet for the proper size gear.

[MiNi Beast]

[MiNi Beast]

tire size helps the equations as well

[derf]

3.07 with 205/75R15 = 31

3.07 with 225/75R15 = 30

3.55 with 205/75R15 = 36

3.55 with 225/75R15 = 34

 

This could possibly vary depending on the exact tire you get as tires aren't exactly the same.  But an average sampling of the tire sizes pops out those results.

[Muncher]

1 hour ago, MiNi Beast said:

This does help.  I think I'll just get one for 4.10 gears and 33 inch tires because that is the plan in the long term. 

[Muncher]

Would this work? Its a 33 tooth long shaft. Says it works for 53 to 90 jeeps but just wanna make sure 

[MiNi Beast]

19 minutes ago, Muncher said:

This does help.  I think I'll just get one for 4.10 gears and 33 inch tires because that is the plan in the long term. 

thats the idea. or for those that care you can just run a standalone gps for mph. just what i do. 

[Sir Sam]

Another option is to check with gps how far off you are, pull your current gear tooth and then do the math to see what your ideal tooth count is, and then decide what to order, I prefer to have my speedo read a little high to help avoid speeding a little too much. 

[JMO413]

Most smart phones will be able to get an app for GPS speedometer. I have one on my phone that I used before I changed my speedometer gear. My speedo is now spot on. I used a chart very similar to the one above.

[ghetdjc320]

And don’t forget to get a tape measure to get your actual tire size. Most 33’s are 32’s or even 31’s when new. 

[75sv1]

I think Iron Rock list what their speedo gears work with.