How to find axle gear ratio

Four ways to determine the ring and pinion gear ratio your axle has! Works for assembled axles in the junkyard or bare gears.

You can figure out the gear ratio of your ring and pinion in a few ways. I show multiple in the video but bottom line is your ring and pinion ratio is:

Number of ring gear teeth ÷ Number of pinion teeth = gear ratio

[WebWheeler]

In case you didn't notice, the ratios are different because they are different axles haha. Also, when counting rotations of the pinion and tires, both tires should be spinning to get an accurate reading. If only one side is spinning (ie if you have one tire jacked up and the other planted on the ground, ) the free tire spins twice as fast. That means you need to count how many rotation the pinion does in two rotations of the tire to get the estimation of the gear ratio

[edgarparedes]

Holy this guy explained it so easy for anyone to understand with multiple methods . Fantastic video thank you 👍🏻

[jamesroberts]

The best description on how to determine gear ratio.

[davidscouller]

Thank you so much I've got more info from you short video than I have gotten in the last hour watchin other videos and even Google

[tylerpool]

All the other videos talking about Multiply then divide moving decimals im like i know I don’t have to do all that great video man i gave it a thumbs up

[Magical_Flame]

helped me figure out whats in my jeeps DANA 30 & 8.25

[michaelcesario]

Saved me a lot of work with the dividing the number part thanks so much

[Keriachamasii]

Thanks for the info… that’s what was looking for 👏👏👍🏼👍🏼

[jamesmacdonnell]

I Bought a brand new in 2010 Ford f250 super duty FX4 4 x 4 with a 6.4 L diesel engine. Will the dealer be able to know which Dana axles I have and what gears are in the differential? No one ever changed/ touched the truck. Thanks for any help_Jim

[TomJones]

Can you switch the Inner Gears from a 1/2 ton into a 3/4 ton axles, as long as its a 44 and the same ratio? GM...

[charlesmarshall]

Could not have made it simple thanks man

[timcarter]

why did you say it was most definitely a 4.10 gear ratio then count and say it was 3.7 ? so is the spin test not right lol

[DIGGER]

hey, i now take my m12 die grinder to the junkyard with me

[bbdeb]

hello i broke my rear diff 3.92 dodge ram 1500 5.7 hemi 2012 4X4 I can not find same model the country where I live I found something else 3.21 My question is whether you will it work?sorry for my english!!

[tonycavitt]

Does Chevy 10 bolt have gear ratio of 3.70 ??
10 and 37 .

[SonomaComa]

Why is it written as 3.73 gear ratio but turning the pinion gear shows 4.10 gear ratio?

[guidosarducci]

Thank you for post. I was curious if you could run another size pinion gear with that 41 tooth ring gear? for example could use a 10 tooth or 12 tooth instead of the 11 tooth pinion gear that's already in there? It seems logical to me that only an 11 tooth pinion gear will work with that 41 tooth ring gear. So can u use a different pinion gear with that ring gear? I subbed & liked

[aceminefee]

Mine won’t turn is it because I don’t have a yoke on the reared

[RalphSampson...]

Okay but, by turning the pinion to turn the wheel you came up with a 4.10:1 ratio.

Counting teeth is the exact method.

Is the difference in the two methods because you have an open differential and you should have stopped one wheel from turning? Would that then have given you the correct ratio?