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TZ102Z2ABA vs TZ102Z2AAA Auto Trans Differences: GOT ANSWERS!

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See further down for answer!

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Bought a 96 Legacy GT from a board member that has trans issues. I have another trans but the ID# is different. Both Transmissions list for a 96 Legacy with a 2.5, but not the same postfix.

So, can anyone tell me the difference betwen these two Transmissions:

 

TZ102Z2ABA Lists as being for a Touring Wagon (they said so it's an Outback)

and

TZ102Z2AAA List as the correct unit for a GT

 

I'm guessing the only difference is first and second gear ratios but I have no idea. Any help is greatly appreciated.

 

Thanks,

Keith

  • Author

Anyone have any ideas? From what I can tell there is no difference in final drive ratios between ANY Legacy automatics for 96, so it still leads me to believe it could just be a gear ratio thing.

 

Keith

I really don't know the difference, but since the final ratio is the same, I'd check the TCU (transmission control unit) to see if they were the same part number. If so, then it is a simple swap, if not, then you'll need to swap out the TCU also.

 

This confusion with electronically controled auto trannys is one of the reasons that I stick with manual trannys, but because my wife won't learn how to drive a manual, I have at least one auto in the stable.

  • Author
I really don't know the difference, but since the final ratio is the same, I'd check the TCU (transmission control unit) to see if they were the same part number. If so, then it is a simple swap, if not, then you'll need to swap out the TCU also.

 

This confusion with electronically controled auto trannys is one of the reasons that I stick with manual trannys, but because my wife won't learn how to drive a manual, I have at least one auto in the stable.

 

 

Hmm, Hadn't thought about that part. As it turns out when I look on http://www.car-parts.com is does seperate 2.5 SW outback from 2.5 SW non outback and even different appears to be 2.5 sedan. So now I think I'm even more confused.... :confused:

 

So, does anybody else know anything? How those of you that work at dealerships and can look through the computers there.

 

Keith

Not sure about the ABA vs. AAA in the code, maybe Jamie (Subie Gal) at Chaplins could look up the code breakdown for you?

 

I doubt the TCU will be an issue, I'm running a '97 4EAT converted to 3.9:1 with the stock '92 TCU in my SS without issue.

 

Gary

  • Author
Not sure about the ABA vs. AAA in the code, maybe Jamie (Subie Gal) at Chaplins could look up the code breakdown for you?

 

I doubt the TCU will be an issue, I'm running a '97 4EAT converted to 3.9:1 with the stock '92 TCU in my SS without issue.

 

Gary

 

Well, here is what I've been thinking:

#1 the connectors appear to be identical between the trans in the car and the trans I've got.

#2 the http://www.car-parts.com database seems to be really really good about knowing interchangability.

and

#3 I'm still betting that the 1st and second gear ratios are different between the two since One is from a GT (sporty model with better suspension so It ought to have lower gearing to accelerate better) and the TCU would only be different to control different shift points, with the GT revving higher before normal shifting (once again because it's a sporty model)

 

So, I think I'm going to call my local parts guy and see what he has to say, but I think I'll also send a PM to Jamie.

 

Thanks,

Keith

  • Author

Well, for any of you that have read this and cared I got some answers from my local Subaru Dealer Parts guy today. :banana: According to everything he has, the last two letters in the code mean NOTHING :headbang:

 

He said there is a meaning for every other letter or number, including the first of the AAA/ABA combo, but the last two list as having no meaning. So we kinda figured it was just Subaru's way of tracking what trim level (GT/OB/LSI...) the unit came from. So the fact that OB vs GT vs Sedan had different TCUs must mean that they all used the same trans with the same gearing, just used different TCUs to set the shift points. So, It looks like I've got a complete unit I can swap into this car.

 

Keith

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