What ratio is my diff?

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A112H
Posts: 7681
Joined: Tue Mar 24, 2009 5:01 am

What ratio is my diff?

Post by A112H »

I posted this on JNC and thought i should bring it over.
If open wheeler, make sure the car is out of gear, chock the front wheels, jack the drive wheel up (usually the R/H side) and spin it two full turns. Count the rotations of the tail shaft/Drive shaft/Prop shaft and you will have your ratio :thumpsup:

If it is a LSD, make sure the car is out of gear, chock the front wheels, raise both rear wheels and turn the tail shaft until the wheels make one full rotation, the amount of times you need to turn the tail shaft is your ratio :thumpsup:


For both diffs if the tail shaft turns 3.5 times you have a 3.5:1 diff ratio
The reason for turning the open wheeler twice is because you are simulating cornering and the inside wheel would spin at twice the speed.

Hope this helps (H)
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