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1998 Legacy GT Transmission Help Needed

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I am replacing my transmission in 1998 Legacy GT with a Transmission from a 1999 Legacy GT. the problem is on the 1998 Trans on the top right side, toward the front of the transmission there is some sort of sensor. the 1999 trans does not have this or any thing like it. This sensor sits on the case right behind the torque converter. What do I need to do to ensure this swap over works correctly? Do I need to separate the front from the back and use the 1998 front?

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I didn't notice the difference until I took the 98 one out. I have a crashed 99 that I stole the motor from 2 years ago and everything on that worked fine so I just figured the tranny would work also.

 

I read on this forum that I need to change the final drive (I assume this is where the axles go) then somewhere else I read about changing the rear differential.

 

If the final drive is where the axles go into, it is the part that is different. Can I swap this out and use the 1999 tranny?

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i do not know about the manual trans.

 

for the auto trans:

 

the 99 GT trans will not work in your 98 GT. the 99 is a phase 2 trans, the wire harness and connectors are different because there are more sensors on the 99.

 

compare the the trans ID numbers on the bell housing at the starter. if the first 6 letter / numbers are not the same it will not fit. the 98 GT is a TZ102Zxxxx, the 99 is different.

 

your 98 GT can use any of the following auto trans (in preferred order):

96 - 98 GT, perfect match, any year.

96 - 98 outback, same trans, but the speedo gears are a little different. your speedo may be a little off.

96 - 97 LSi, same trans but i ASSUME the speedo will be off. there are not a lot of these around.

 

in the late 90s the ej25 cars had a different final drive ratio than the ej22 cars.

 

you CAN NOT use any auto trans from a 2.2L car UNLESS you swap in the matching rear diff. i would not even consider this unless the trans was almost free, or better. there are lots of 96 - 98 auto trans available that came from the ej25 cars. use one of them.

 

good luck.

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Glad to see one thread.

 

How about a USEFUL location associated with your ID.

 

Some of us may be able to help you out.

 

For instance I have a trans in a 97 Outback parts car.

 

Your current location is rather useless - wouldn't you say?

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i do not know about the manual trans.

 

for the auto trans:

 

the 99 GT trans will not work in your 98 GT. the 99 is a phase 2 trans, the wire harness and connectors are different because there are more sensors on the 99.

 

compare the the trans ID numbers on the bell housing at the starter. if the first 6 letter / numbers are not the same it will not fit. the 98 GT is a TZ102Zxxxx, the 99 is different.

 

your 98 GT can use any of the following auto trans (in preferred order):

96 - 98 GT, perfect match, any year.

96 - 98 outback, same trans, but the speedo gears are a little different. your speedo may be a little off.

96 - 97 LSi, same trans but i ASSUME the speedo will be off. there are not a lot of these around.

 

in the late 90s the ej25 cars had a different final drive ratio than the ej22 cars.

 

you CAN NOT use any auto trans from a 2.2L car UNLESS you swap in the matching rear diff. i would not even consider this unless the trans was almost free, or better. there are lots of 96 - 98 auto trans available that came from the ej25 cars. use one of them.

 

good luck.

 

That is Kinda what I was concerned about. Thank you for the help.

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No if the '99 is a phase II you won't be able to make it work in a phase I application without a lot of effort. Probably need the wiring harness and TCU at the minimum, then figure out how to make it communicate with your old ECU for torque cut etc. Plus the VSS's are probably different and so on.

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Glad to see one thread.

 

How about a USEFUL location associated with your ID.

 

Some of us may be able to help you out.

 

For instance I have a trans in a 97 Outback parts car.

 

Your current location is rather useless - wouldn't you say?

 

Located in Southern NH.

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No if the '99 is a phase II you won't be able to make it work in a phase I application without a lot of effort. Probably need the wiring harness and TCU at the minimum, then figure out how to make it communicate with your old ECU for torque cut etc. Plus the VSS's are probably different and so on.

 

 

 

Right on. the 99 is for sale on craigslist. Looking for a 98. Where is the TCU Located?

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Sounds good, if you can get the transmission model codes from your existing and from the new then you can make sure the ratios match up. Someone had a nice spreadsheet with the model codes here somewhere. Sometimes on the rear diffs there will be a sticker on them with the ratio but not always.

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Where is the TCU Located?

 

it is located under the dash on the driver side. it is easier to find if you remove the kick panel and then look up.

 

but more important, why do you want to know. the TCU is not relevant to the trans swap. you do not need to mess with it and you absolutely do not want to mess with it unless there is a really good reason. it is not part of your problem.

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i do not know about the manual trans.

 

for the auto trans:

 

the 99 GT trans will not work in your 98 GT. the 99 is a phase 2 trans, the wire harness and connectors are different because there are more sensors on the 99.

 

compare the the trans ID numbers on the bell housing at the starter. if the first 6 letter / numbers are not the same it will not fit. the 98 GT is a TZ102Zxxxx, the 99 is different.

 

your 98 GT can use any of the following auto trans (in preferred order):

96 - 98 GT, perfect match, any year.

96 - 98 outback, same trans, but the speedo gears are a little different. your speedo may be a little off.

96 - 97 LSi, same trans but i ASSUME the speedo will be off. there are not a lot of these around.

 

in the late 90s the ej25 cars had a different final drive ratio than the ej22 cars.

 

you CAN NOT use any auto trans from a 2.2L car UNLESS you swap in the matching rear diff. i would not even consider this unless the trans was almost free, or better. there are lots of 96 - 98 auto trans available that came from the ej25 cars. use one of them.

 

good luck.

 

I am assuming that any 96-98 Legacy would also work. If I use an outback can I change the speed sensor to have the speedo read correctly? Do you know how much off it would read.

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I am assuming that any 96-98 Legacy would also work. If I use an outback can I change the speed sensor to have the speedo read correctly? Do you know how much off it would read.

 

you CAN NOT use any auto trans from a 2.2L car UNLESS you swap in the matching rear diff.

this includes ALL legacy L or brighton.

 

the GT is a 2.5L car and does not fall into this group.

 

the difference in the speedo is exactly the same as the difference in the tire size. with stock tires about 5.7% or about 4 mph at 70. speedo will read 70, actual speed will be ~66.

 

there is no easy way to correct the error. you would have to open the trans case. do not try it. it isn't worth it.

Edited by johnceggleston

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Ok, I have located a tranny for a 1998. New problem. I didn't mark the torque converter with the flex plate and even worse is I don't know which is the 98 torque converter which is the 99 torque converter. Does it matter and what can I do to fix this? I think I read somewhere that the torque converter is matched to the fllexplate.

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I don't know about the torque converter compatibility, but I do know from other posts that is critical to get the torque converter seated properly before mating it back up to the engine. Trying to use the engine mating bolts to 'snug it up' results in a cracked ATF pump and having to do the job over again.

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I am assuming that there should a small space between the converter and the flex plate when the bell housing is touching the motor. I know this is the case with other makes.

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