2005-2016 Tacoma Axle Codes

@Jeff Lange

Well the tach could read incorrectly, but it didn't and it doesn't, in addition to the iPhone speedo app I used an Ultra Gauge that plugs into the ODB port and show dozens of ECU generated parameters in real time, RPM among those. It gets the same original tire sized speed info from the ECU as what the speedo displays. They match though both are wrong because of the significant tire diameter increase. Easy to double check.
Also it's very, very easy to tell when the torque converter is locked up. I checked many times at 2 specific reference RPMs in 2 gears,(on a flat level road) in third which is 1.000, and fourth which is 0.705 locked up, it's still 0.705 not locked up but I get your drift. The diff has never been changed, as far as I know. I know what gear it should have. Though somewhat unlikely I thinks it's more likely that the truck was just built with a different ratio rather than the verifiable method I described in my first post being completely wrong.

 

Yup, I agree. If you used the RPM reading from the OBD/CAN data, the speed reading from a GPS unit (or phone app), know that the torque converter was locked up, and can verify the tire radius or close to it when loaded with the vehicle weight it's a good way to verify the differential ratio in the truck.

Toyota never officially built a 2WD 4-cylinder Tacoma with a 3.73:1 ratio, so if that's indeed what your truck has, it would seem that it was either built incorrectly at the factory, or the gearing was changed at some point (different parts ordered for a repair or modification). If you're the original owner and you've never had repairs done to the differential, it seems likely that the truck was erroneously built with 3.73:1 gears.

It would seem to me that they would verify things like that as a quality assurance check before the truck leaves the factory, especially from someone like Toyota, but it's possible, especially on a 2WD truck.

EDIT: For others wondering why we were discussing where the data was coming from, the acceptable error in the tach is -4% to +2% and for the speedometer it is 0% to +5%, while the difference between 3.58 and 3.73 gears is ~4%.

Jeff

 

Manual with 3.9?

 

2017 2.7L 5-speed Manual with 8.8" 3.91:1, yup.

Jeff

 

So before regearing or adding locker, upgrading to 8.75 should be considered

 

No, you already have 8.75, I just rounded it to 8.8.

Jeff

 

All OR and Pro have the 8.75 along with all 3rd Gen MT models.

 

It’s not my vin, I found this on salvage yard to verify not all MT have 4.3

 

Oh okay, yeah, not all MT's are 4.3. Is that a thing people think?

For 2016+, all M/T's are 8.8", all 6MT's are 4.30, and all 5MT's are 3.91.

Jeff

 

I'd there a table with the codes for the Mexico made trucks?

 

I don’t think it matters where it’s manufactured but rather if the truck is made for the US market

 

The Mexico manufactured axle codes don't conform to the table at the beginning of this thread.

 

Yes, it is a peculiarity. Still been meaning to go through and assess the Mexico codes.

For your truck, A04D = 3.91:1 8.8" with Locker.

Jeff

 

I just tried this method on my 2020 SR I4 Auto, axle code A07A, Mexico

https://youtu.be/RNgjS5mHI0E

21.5 / 10

So I have 4.3 final drive

 

Yes, that's correct, though gear ratios in general are actually pretty straightforward on the Tacoma just by knowing the year, engine, transmission, and drive type.

Here are the gear ratios by model/application for 2005-2020:

2005-2015

2.7L L4
5-lug 4AT: 3.583 (8.0" Open)
5-lug 5MT: 3.308 (8.0" Open)
6-lug: 4.100 (8.0" Open)

4.0L V6
X-Runner: 3.153 (8.0" LSD for 2005-2006, 8.0" Open for 2007-2015 with Available 8.0" LSD for 2007-2008)
6-lug 6MT: 3.727 (8.0" Open, Available 8.0" with Rear Diff Lock, or Available 8.0" LSD for 2005-2008)
5AT: 3.727 (8.0" Open, Available 8.0" with Rear Diff Lock, or Available 8.0" LSD for 2005-2008)

2016-2020

2.7L L4:
6AT: 4.300 (8.0" Open)
5MT: 3.909 (2016-2017 Only, 8.8" Open)

3.5L V6
6AT: 3.909 (8.0" Open or Available 8.8" with Rear Diff Lock)
6MT: 4.300 (8.8" Open or Available 8.8" with Rear Diff Lock)

All front differentials are open, rear differential lock is standard on TRD Off-Road and TRD Pro models, rear mechanical LSD is standard on 2005-2006 X-Runner and available as an option on other 2005-2008 4.0L V6 models, all others use open diffs for the rear differential.

Everyone should be able to easily tell what ratio and size of differential they have, and whether or not you have diff lock. The only real question some people may have would be if their 2005-2008 has LSD or Open.

Jeff

 

2019 San Antonio TRD Off-Rood with manual transmission.

 

MT V6 gets 4.30

 

Correct. I have a 8.75” rear differential (model BD22AN, made by Hino) with eLocker and a 4.30:1 ratio.

I found some additional specifications on one of the differential repair/modification sites (I can not vouch for the accuracy of the information):

High strength steel axle tubes
43 ring teeth and 10 pinion teeth
32 spline axles @ 1.37” dia.
34 spline pinion @ 1.77” dia.
Internally mounted electro-mech eLocker (see attached photo)

 

My code is A04A. Is it possible to purchase a locker axle from Toyota that's the same ratio and would it work on my truck? Or does the larger diff size matter even if the gear ratio is the same?