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View Full Version : How Can I figure out what gear I have?



PaulFiveOh
04-03-2007, 02:45 AM
I'm fairly certain now that my suspect 4.10's are infact 4.30's or worse.

If I make a mark on the driveshaft, then rotate the wheels 360 and count the revolutions of the driveshaft, will I be able to distinguish between 4.56's and 4.30's? I dont think I will.

Is there any other for sure way using Math or what not to figure my ratio?

Paul408Notch
04-03-2007, 03:36 AM
Yes, you can tell the difference between them by the revolutions. 4.56 gears you'll spin the driveshaft almost exactly 4.5 turns. 4.30s will turn barely over 4+1/4 turns.

Mark the wheels and turn the driveshaft though, you can be more exact that way. Just make sure both wheels are spinning at the same time or it can throw your count off.

PaulFiveOh
04-03-2007, 03:41 AM
Got ya.

Is it possible to rotate by hand with the wheels on or is it too much weight?

89notch
04-03-2007, 07:48 AM
Got ya.

Is it possible to rotate by hand with the wheels on or is it too much weight?

yea just jack the rearend up to get the wheels off the ground. Take some chaulk and mark the whel and count how many revolutions the driveshaft makes.

PaulFiveOh
04-03-2007, 10:01 AM
Cool, thanks guys.

Kevin Doe
04-03-2007, 10:09 AM
I agree, portions of a turn will be hard to tell the difference. So, what I would do is rotate the pinion enough times to rotate the wheels two full revolutions. This will exasterbate the difference between the two ratios.

You'll need to compare to 4.30*2 though. But the difference between the two becomes larger with more output rotations.