Axle Ratios

[Singtoe]

I just bought a 99 limited 4x4 and i am trying to figure out the axle ratio. The door jam sticker says A03A but my friend's 2002 2x4 says A03A too. How can i determine the exact ratio.

 

[Pikeman]

Please use the search feature. There are a few dozen threads on this already. I will go ahead and edit this post in a minute with a link or two for you.

 

[cordrayj1]

info u need:

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

 

[Singtoe]

Please use the search feature. There are a few dozen threads on this already. I will go ahead and edit this post in a minute with a link or two for you.

I have used the search function and there are code interpretations that say my axle ratio is 4:10 but when I do the spin the one tire test - I count 45 and 2/3 rotations of the drive shaft per 20 times the wheel is spun.

I have exhausted the search function and now I would like to know what my Toy has.

 

[Pikeman]

Well tell us more about what year and package your 4 Runner is and the will let us help you better. If you are 4wd V6 and not e-locked then 4.10 is the most common. 4.30 if you are e-locked.

http://www.toyota-4runner.org/3rd-gen-t4rs/60096-gear-ratios.html

If you are 4cyl or the PO changed ratios then the 4.56 ratio that you get by your tire rotations might be accurate.

 

[AddictedOffroad]

The axle codes on the VIN tag are worthless in these years. Mine said I had 4.56s, yet they were 4.30s when they were pulled. My 2wd said it was 4.30, but it was 4.10s when pulled.

 

[cordrayj1]

I have used the search function and there are code interpretations that say my axle ratio is 4:10 but when I do the spin the one tire test - I count 45 and 2/3 rotations of the drive shaft per 20 times the wheel is spun.

I have exhausted the search function and now I would like to know what my Toy has.

did u follow the link i posted previously? its pretty cut and dry.

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

 

[Nelsonmd]

Yeah, tons upon tons of threads about this and info on the web. Just use google.

And now to save you the time, there really is a correct answer.

And it is....

Lift a wheel, spin it, and count the drive shaft rotations. There have been tons of discussion of what is the best chart based on axle code, VIN, features, etc, and none of them are 100%. It is easy to count them yourself, so save your time and effort and just do it.

 

[Singtoe]

did u follow the link i posted previously? its pretty cut and dry.

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

I followed the link and it says that i have 4.30 ratio with 265/70-16 tires.

This still doesn't explain the tire , drive shaft rotation test. What is the proper way to calculate that?

I have every receipt the original owner had and no ring and pinion change out.

There was an engine replacement done at 80k miles. timing belt at every 60k miles. religious oil changes at every 5K miles. Water pump at 120k but no axle issues.

 

[cordrayj1]

The axle codes on the VIN tag are worthless in these years. Mine said I had 4.56s, yet they were 4.30s when they were pulled. My 2wd said it was 4.30, but it was 4.10s when pulled.

oops, my bad. this happen to anyone else?

 

[Nelsonmd]

oops, my bad. this happen to anyone else?

Oh yeah, happened to me.

I followed the link and it says that i have 4.30 ratio with 265/70-16 tires.

This still doesn't explain the tire , drive shaft rotation test. What is the proper way to calculate that?

I have every receipt the original owner had and no ring and pinion change out.

There was an engine replacement done at 80k miles. timing belt at every 60k miles. religious oil changes at every 5K miles. Water pump at 120k but no axle issues.

I don't know, the search function pulled up about 5 different posts with the info in my first search... Here's one... http://www.toyota-4runner.org/3rd-gen-t4rs/69449-rear-diff-i-d.html

Don't worry about work history, etc. This is very simple and it is pretty fool proof. You can read a million different posts with charts and guides on what ratio you have, but this is way easier and actually correct.

 

[brian2sun]

I have used the search function and there are code interpretations that say my axle ratio is 4:10 but when I do the spin the one tire test - I count 45 and 2/3 rotations of the drive shaft per 20 times the wheel is spun.

I have exhausted the search function and now I would like to know what my Toy has.

You have 4.56s then.

 

[Pikeman]

Well tell us more about what year and package your 4 Runner is and the will let us help you better.

then the 4.56 ratio that you get by your tire rotations might be accurate.

Thought I said that earlier....oh wait I did.

 

[Singtoe]

Is it common for 4.56 to be in a 99 Limited 4x4 4runner?

What rpm should it be reading at 70 MPH?

I just want to be sure before i start ordering parts.

 

[Limited2K]

Mine's 2wd, and I have 4:10s and it idles at about 2200 rpm at 70 mph.

 

[rjaudi]

If your 4runner is stock than A03a is 4.10 axle ratio. I stumbled across what the codes mean looking at parts online at Toyota Parts Zone.

 

[brian2sun]

[/B]

Thought I said that earlier....oh wait I did.

I just thought you weren't sure when you said it "might be accurate". I don't see any way it couldn't be 4.56s as long as he counted 45 and 2/3s driveshaft revos. That's as accurate as it gets AFAIK.

Is it common for 4.56 to be in a 99 Limited 4x4 4runner?

What rpm should it be reading at 70 MPH?

I just want to be sure before i start ordering parts.

Tire size, tread wear, and how level the road is are big variables so you can't go off rpms compared to a similar vehicle. You really can't possibly have 4.30s or 4.10s if you counted 45.6 revolutions after spinning the tire exactly 20 times. This method is much more accurate than looking up your doorjam code on the internet because like Pikeman siad, the PO may have changed it and the internet charts can be totally wrong (which I know because they were wrong on mine).

If you still aren't convinced the only other way is to count the teeth of the ring gear and divide it by the number of teeth on the pinion gear, but you have to take it apart to do that. I admit it is rare for a 4x4 Limited to have 4.56s but it's not that unlikely that it wasn't switched by the PO. And some did come from the factory like that so it's not unheard of.

 

[Singtoe]

Is it good to have 4.56 ratio or would the 4.10 be better - For gas mileage? Mind you, i am running the stock 265 tires and no lift.

 

[Nelsonmd]

Is it good to have 4.56 ratio or would the 4.10 be better - For gas mileage? Mind you, i am running the stock 265 tires and no lift.

Well, you get more wheel revs per prop shaft rev, and you aren't really taxing the engine too much, so you could argue the 4.10 is better....

But except for the 2WD Auto's, they all pretty much have the same MPG rating, so I wouldn't count on getting a difference. It certainly wouldn't be enough to warrant an axle swap (especially for 4WD).

Out of curiosity, what work are you doing on it that you are ordering parts that depend on the diff ratio?

 

[Singtoe]

Well, you get more wheel revs per prop shaft rev, and you aren't really taxing the engine too much, so you could argue the 4.10 is better....

But except for the 2WD Auto's, they all pretty much have the same MPG rating, so I wouldn't count on getting a difference. It certainly wouldn't be enough to warrant an axle swap (especially for 4WD).

Out of curiosity, what work are you doing on it that you are ordering parts that depend on the diff ratio?

No work. I bought a wrecked 4-runner and it has the 4.10 diffs in it. So only my labor and new oil and gaskets.

If it doesn't improve gas mileage, then the switch out is really not really beneficial.