Very confused on gear ratio?

[TheManOutside]

Ok, so I am a little confused/concerned with my gear ratio... I have a 1997 Automatic lame sauce 2wd. I wanted to know the gear ratio, so I did the wheel spin test... 4 times too. The first time, I got 18.5, second 19, third 19, fourth 19 (full driveshaft spins). I did it with 1 tire off the ground and I have an open diff. I spun the tire 10 times and multiplied the driveshaft revolutions by 2 because of the 2 tires. so, math.

19x2=38
38/10=3.8
GEAR RATIO=3.8
huh.

The door jam info thing on my truck (where it shows VIN, barcode, etc.) says A01A for my gear info. According to this website, Gearratiosanddiffs, that means my gear ratio is 3.42. huh?

So, either my gears were upgraded or I did the test wrong. I dunno. I was expecting a ratio of at least 4.1. Either way, 3.42 or 3.8 seems pretty low, are these numbers normal/common?

Also, how hard is it to upgrade gear ratio? Thanks!

 

[jmsdad]

If the POs haven't changed out the diff, you have 3.73 ratio.

 

[TheManOutside]

If the POs haven't changed out the diff, you have 3.73 ratio.

I'm not sure if they did or not... oh well I guess. Do you know if it's relatively easy/straightforward to upgrade gears?

 

[BrandonF]

I'm not sure if they did or not... oh well I guess. Do you know if it's relatively easy/straightforward to upgrade gears?

To clarify, a higher numerical ratio creates "lower" gearing.

First of all, why do you want a different gear ratio? Going to lower gearing is not necessarily an upgrade. People generally regear to get more power to compensate for oversized tires and additional vehicle weight. The compromise is that you will be revving higher on the highway.

Your cheapest option would be to swap in a whole third member off of a wrecked 4runner that has your desired gearing (so a 4wd model). This will be either a 4.10 or a 4.30 gear ratio. If you don't know, the third member is the chunk that bolts into the axle housing and then has the drive shaft coming into it at the front. You can probably find one for $100 or less and it is a pretty straight forward job to install. You don't actually have to set any gears up.

The other option is you buy a new gear set. This will run you around $300 for parts and then the gear installation and setup is very specific. If you're asking how hard it is, you should have it done by a professional at a shop. This could be another $200.

 

[T4R2014]

Assuming that it rolled off the dealer lot on 225/75R15's, it should have a 3.73 axle ratio. You might find it pretty quick on stock size tires.

 

[wshyangmur]

You can probably find one for $100 or less and it is a pretty straight forward job to install.

 

[TheManOutside]

To clarify, a higher numerical ratio creates "lower" gearing.

First of all, why do you want a different gear ratio? Going to lower gearing is not necessarily an upgrade. People generally regear to get more power to compensate for oversized tires and additional vehicle weight. The compromise is that you will be revving higher on the highway.

Your cheapest option would be to swap in a whole third member off of a wrecked 4runner that has your desired gearing (so a 4wd model). This will be either a 4.10 or a 4.30 gear ratio. If you don't know, the third member is the chunk that bolts into the axle housing and then has the drive shaft coming into it at the front. You can probably find one for $100 or less and it is a pretty straight forward job to install. You don't actually have to set any gears up.

The other option is you buy a new gear set. This will run you around $300 for parts and then the gear installation and setup is very specific. If you're asking how hard it is, you should have it done by a professional at a shop. This could be another $200.

Alright, good to know. The reason I want to know my gear ratio is because I am going to (hopefully) be doing a 4wd conversion by the end of this year, and I have to have a front diff with a gear ratio matching my rear diff. From what I know/have heard, the 4wd 4runners tend to have a higher gear ratio (4.1 I THINK). Since my gear ratio is probably 3.73, I would more than likely have to re-gear the rear diff to match the front, which is not a huge problem. I also plan on getting bigger tires, but not too big, so I don't think a re-gear would be necessary, but still a good idea (I want to get 33's).

 

[TheManOutside]

Assuming that it rolled off the dealer lot on 225/75R15's, it should have a 3.73 axle ratio. You might find it pretty quick on stock size tires.

I currently have 245/75R16's. I didn't put these on, and I'm not sure if these are the same size as what it came with from the dealer. I'm pretty sure 3rd gens came stock with this size and 225/75R15's, correct?

 

[BrandonF]

I currently have 245/75R16's. I didn't put these on, and I'm not sure if these are the same size as what it came with from the dealer. I'm pretty sure 3rd gens came stock with this size and 225/75R15's, correct?

The 4wd models came with 265/70/16 tires which is considered a 31". If you are doing a 4wd conversion and plan to run 33's, definitely try and find diffs with 4.3 gearing.

 

[TheManOutside]

The 4wd models came with 265/70/16 tires which is considered a 31". If you are doing a 4wd conversion and plan to run 33's, definitely try and find diffs with 4.3 gearing.

Alright. so if I find a donor with 4.3 gears, I can easily (for the most part) change my rear diff gears using the donors, correct?

 

[csp]

Just swap the third member from the donor rear axle to your.

As was said, higher number = lower gears

 

[baja1]

Im totally ignorant about these things but if a 96-04 tacoma rear end interchanges, there's a guy that just listed a 4:10 E-locker in fullerton,95K miles. look on "Offroad Desert Deals Classifieds" on FB

 

[pluton]

The door jam info thing on my truck (where it shows VIN, barcode, etc.) says A01A for my gear info. According to this website, Gearratiosanddiffs, that means my gear ratio is 3.42. huh?

FYI: It has been established, to the satisfaction of most here at T4R.org, that the door labels in this and previous generations of Toyota trucks do not necessarily have anything to do with the axle ratio that actually exists in the particular truck in question.

 

[TheManOutside]

Im totally ignorant about these things but if a 96-04 tacoma rear end interchanges, there's a guy that just listed a 4:10 E-locker in fullerton,95K miles. look on "Offroad Desert Deals Classifieds" on FB

I'm also totally ignorant on gears as well. :/ That E-Locker does sound tempting, and 96-04 Tacoma's are interchangeable with 3rd gen 4runners, however I'm not sure about the diff/gears... Can someone confirm this?

Thanks for the post, but unless the lockers really cheap I'm gonna pass. I'm saving up my $$$ for the big conversion :eyebrows: Do you have a link to the E-Locker?

FYI: It has been established, to the satisfaction of most here at T4R.org, that the door labels in this and previous generations of Toyota trucks do not necessarily have anything to do with the axle ratio that actually exists in the particular truck in question.

Yeah, I thought it be worth a look anyway. Turns out it was pretty far off ha

 

[BrandonF]

I'm also totally ignorant on gears as well. :/ That E-Locker does sound tempting, and 96-04 Tacoma's are interchangeable with 3rd gen 4runners, however I'm not sure about the diff/gears... Can someone confirm this?

Thanks for the post, but unless the lockers really cheap I'm gonna pass. I'm saving up my $$$ for the big conversion :eyebrows: Do you have a link to the E-Locker?



Yeah, I thought it be worth a look anyway. Turns out it was pretty far off ha

Be aware that the elocker third member cannot be simply swapped into a non-elocker axle housing. The elocker third bolts up differently to the axle housing and will require welding and tapping new holes.

This is why when I swapped in an elocker, I did the whole axle housing.

 

[SupaSupra]

Assuming that it rolled off the dealer lot on 225/75R15's, it should have a 3.73 axle ratio. You might find it pretty quick on stock size tires.

They are, I've out run a few Civics and Integras in my 2WD woth stock size tires. But these tires are no good for offroad which is what I want to do.

 

[TheManOutside]

Be aware that the elocker third member cannot be simply swapped into a non-elocker axle housing. The elocker third bolts up differently to the axle housing and will require welding and tapping new holes.

This is why when I swapped in an elocker, I did the whole axle housing.

Really? I didn't know this. That's actually very helpful thank you

 

[Scramble]

Toyota also made 4:56 gears which are harder to find but would be better for 33" tires. Some members here are not happy with 33" & 4:30 gears.

 

[TheManOutside]

Alright, so, based on the info I've gathered so far...

I currently have a 3.73 gear ratio. When I go search for a donor truck, I should try to find one with 4.3 or 4.56 gears, because I can easily swap out the 3rd member to accommodate the front diff's gears. 4.3's are fine for 33's, but 4.56's are much better. 3rd gen 4runner door labels are basically useless when it comes to differential information.

:thumb:

 

[ShooterMcGavin]

Alright, so, based on the info I've gathered so far...

I currently have a 3.73 gear ratio. When I go search for a donor truck, I should try to find one with 4.3 or 4.56 gears, because I can easily swap out the 3rd member to accommodate the front diff's gears. 4.3's are fine for 33's, but 4.56's are much better. 3rd gen 4runner door labels are basically useless when it comes to differential information.

:thumb:

The 4.56 gears are rare. They only came on 4 cylinder 4Runners with the e-locker. Don't hold your breath to find them.