Dana 300 - Speedo Gears?

[cu4whln]

So I installed a Dana 300 - and now my speedo reads 10 mph high.

Where can I find speedo gears?

AND - How do i figure out which one I need. 3.54 gears with 33 inch tires.

Experts ??

[SJTD]

At what speed is it 10 mph high?

Say it's at 60.

(60+10)x=60y

(70/60)x= y

Where x = # of teeth you've got now, y = what you want

I think.

To figger it out using the rear ratio and the tire size I would need to know the tooth count of the speedo drive gear in the transfer case.

Idunno where to get it, maybe a rear end shop or 4wheelparts.com. Be carefull they don't just want to match the speedo gear tooth count to rear end ratio since you prolly don't have the stock tire size that went with that ratio from the factory.

[tgreese]

You can purchase a small gearbox that adjusts the cable speed inline with the cable - for example https://transmissioncenter.net/shop/...1-888-2012066/ If I went this route, I would skip the most of the math and measure some sample speeds with a GPS. Compare the GPS speed to the indicated speed and calculate how far off you are in percent.

Stewart-Warner used to make a variable device that you may be able to find on the used hot rod parts market. Most speedometers today are electronic, similarly most of the modern offerings for this type of device are also electronic.

The Jeep factory parts catalog has a big table of different speedometer gears, both the driving and driven gears. Unlikely you will find these parts today by their part number though.

[babywag]

google is your friend search for dana 300 speedo chart
any little jeep outfit should have them.