Front diff gear ratio verification - diff removed and no vehicle info

[SDmtnbkr]

Is there a way to verify the gear ratio for a front differential that has been removed from the vehicle and has no other information?

....basically I want to verify that a craigslist front diff is actually a 4.30. The seller says he got it from a junk yard and never ended up using it, so it's not from his truck to verify.

 

[69project]

Count the number of teeth on the ring gear and divide by the number of teeth on the pinion. That should give you the ratio.

 

[SDmtnbkr]

Count the number of teeth on the ring gear and divide by the number of teeth on the pinion. That should give you the ratio.

This is for a FRONT diff, to do that I would have to break the case open, which I would rather not have to do.

 

[99Runnr]

Spin the pinion flange and count the rotations of the CV.

 

[Chim]

There may be a color coding on there.. Check the pinion nut and see if there was a little spot of paint. Mine had pink and that's what was used for 4.10 gearing and I confirmed that by rotations.

 

[nevada]

Spin the pinion flange and count the rotations of the CV.

yep, spin it, and count them. do it several times to make sure.

 

[69project]

This is for a FRONT diff, to do that I would have to break the case open, which I would rather not have to do.

I see others have mentioned other methods which should work. Are there any casting numbers on the case you can look up? That will definitely lock it in for sure, if you know no one has changed the ring/pinion out.

If you have any kind of access to the VIN sticker on the door of the donor vehicle you can look it up using this chart from Sonoran Steel. Basically if it had the 265/70/16 tires it's either a 4.10 or 4.30 (if an E-locker) otherwise it's 3.91. That's what my research pulls up.

http://www.sonoransteel.com/include...eel/TechArticles/1996-2004ToyotaGearRatio.pdf