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Will WRX 6sp fit to '99 2.5 legacy


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The swap would be just the transmission. It has 170k miles on it and getting a little long in the tooth. The engine has a little over 38k miles. No problem with the engine. Current clutch is same miles as engine, and hydraulic.

 

Good question on the final rear gear ratio? Dont know what the WRX is and I could find out what mine is.

 

Thanks to all for the answers. I just figure if I need to swap the 5spd, I would rather have the 6spd if it is possible. I love the car and dont plan to trade. I like to make little improvements as time and money allows. Does the transmission include the viscous coupling?

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What about the driveshaft?

 

Do 6 speeds come with the R160 rear end?

 

No, R180, but you can use an R160, you'll need to have driveshaft made (extended) and get a 6-speed transmission mount.

 

Search nasioc for 6-speed swap. A few people there have done it.

 

like this guy who even sort of has dccd.

 

It's a lot cheaper and easier to get a 5-speed though, and it's not like you'll be breaking gears on the 5-speed, which is why most people do the swap.

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No, the 5spd WRX's have the 3.545, the STi has 3.90.

 

It will swap, but expect to do a lot of custom fabwork like others have said, and don't expect to have a working DCCD unless you wanna do a TON of wiring.

 

OK if I read and interpret this correctly, it sounds like I would need to keep the rear gear the same as what comes with the 6spd. Said another way, if the rear gear in my 99 is different than the gear behind the 6spd, than I need to change both transmission and rear gear. Keep the transmission and rear end together. Right?

 

You lost me on the DCCD?? what is that? Sounds to me like more chasing down the right parts rather than fabrication work.

 

I still like the idea of the 6spd!

 

Thanks for you help.

Mike

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don't expect to have a working DCCD unless you wanna do a TON of wiring.
Well at least a lot of wiring, not sure "TON" would be the correct amount. The main problem would be getting the connector to the DCCD computer. Do you have ABS? The 6 speed DCCD tries into the ABS system also. I used an earlier version in my 96 Impreza and the place for the thumb switch was already there, just had to pop out the cover.
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OK if I read and interpret this correctly, it sounds like I would need to keep the rear gear the same as what comes with the 6spd. Said another way, if the rear gear in my 99 is different than the gear behind the 6spd, than I need to change both transmission and rear gear. Keep the transmission and rear end together. Right?

 

You lost me on the DCCD?? what is that? Sounds to me like more chasing down the right parts rather than fabrication work.

 

I still like the idea of the 6spd!

 

Thanks for you help.

Mike

 

You should go with a 5-speed.

 

Okay anyway the front and rear differentials obviously need to be the same ratio. Your rear diff I believe is the same. Otherwise, swapping in the rear differential from an STi is a whole other project. Firstly, it's bigger and the splines for the axles are different than those for an R160. So, you'd need custom axles made. If you wanted to use the R180 axles, you would have to swap the whole rear end, which means lateral links, axles, and brakes. That would widen the track and mess up the brake bias because the STi has those fancy Brembos. You would also have messed up alignment settings. Not cheap either. You also may or may not be able to re-use your front axles. Otherwise you need some custom made.

 

The 6-speed doesn't have a viscous coupling. It has a fancy center diff that can vary the amount of slip it allows either automatically or manually (DCCD stands for driver controlled center differential). The STi uses various G/yaw/steering/etc sensors to determine the optimum amount of lockup for the center diff. ABS and the handbrake are also incorperated into things too. Without swapping in basically a whole STi drivetrain and ECU/TCU you will not be able to get it to work right in auto mode. You can however rig up a circuit with a potentiometer to control it manually but that's not a great idea.

 

The 6-speed swap will cost at a minimum $3000, and probably more like 5-6 grand. A used 5-speed can be had for less $1000 and bolts right in.

 

Did you read the link I posted earlier?

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You should go with a 5-speed.

 

Okay anyway the front and rear differentials obviously need to be the same ratio. Your rear diff I believe is the same. Otherwise, swapping in the rear differential from an STi is a whole other project. Firstly, it's bigger and the splines for the axles are different than those for an R160. So, you'd need custom axles made. If you wanted to use the R180 axles, you would have to swap the whole rear end, which means lateral links, axles, and brakes. That would widen the track and mess up the brake bias because the STi has those fancy Brembos. You would also have messed up alignment settings. Not cheap either. You also may or may not be able to re-use your front axles. Otherwise you need some custom made.

 

The 6-speed doesn't have a viscous coupling. It has a fancy center diff that can vary the amount of slip it allows either automatically or manually (DCCD stands for driver controlled center differential). The STi uses various G/yaw/steering/etc sensors to determine the optimum amount of lockup for the center diff. ABS and the handbrake are also incorperated into things too. Without swapping in basically a whole STi drivetrain and ECU/TCU you will not be able to get it to work right in auto mode. You can however rig up a circuit with a potentiometer to control it manually but that's not a great idea.

 

The 6-speed swap will cost at a minimum $3000, and probably more like 5-6 grand. A used 5-speed can be had for less $1000 and bolts right in.

 

Did you read the link I posted earlier?

 

I did read the link. But your explaination here helps to define the fabrication stuff and diffeculty with the mechanicals. But if the rear gear is the same ratio between my car and the donor car then the gearing is not the problem. It sounds like the different axles are the main problem. I dont like the custom axles stuff. I also didnt understand the R160 & the R180. Is this the axle difference in diameter? This sounds like the major show stopper.

 

The link you posted was a swap 5mt to 6mt in a WRX. So I can see that he probably had an eaiser time of the mechanicals. I did not realize that there was a difference with the viscous coupling and the DCCD.

 

OK now to swapping the 5mt with 5mt. Is the viscous coupling a part of the transmission? What other watchouts are there?

 

I appreciate your help and explination. Sounds like you have been there done that?? Thanks Jamal.

 

Mike

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starting in '06 (at least in the states I guess) the 5 spd has better first gear synchros. I dunno if there could be other differences making it hard to install.

 

Perhaps someone could find a rebuilt/crashed '06 tranny for you?

 

Carl

 

Thanks Carl,

 

That is the problem I have. The 1st gear synchro is in its last throws.

The '06 sounds like an option to look at. Does the '06 have the DCCD business?

 

The 6mt would be sweet, but too much pain in the rump roast to me.

 

Mike

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For a long while there were MT's out there that were dual clutch action types(hyd or cable compatible)

 

...meaning you could take the fork off the type of car that yours is (cable for example) and unbolt the pivot bolt in the bellhousing and move it to the spot on the bellhousing that you need to change to. Not all of em have this but alot do.

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Thanks Carl,

 

That is the problem I have. The 1st gear synchro is in its last throws.

The '06 sounds like an option to look at. Does the '06 have the DCCD business?

 

The 6mt would be sweet, but too much pain in the rump roast to me.

 

Mike

No, I have just a regul;ar WRX wagon. To my knowledge the DCCD is only on the STI version of WRX sedan. I suppose the '06 MT legacies also got upgraded (conical?) synchros but I'm not sure. maybe one of these other guys knows. I just mentioned cause it seems to me, if it will bolt up and has no other negatives, may as well get an '06 or '07 5spd . Or maybe there is a rebuild kit with upgraded synchros you could throw in a low mileage junkyard tranny from a pre-'06.

 

sorry - maybe someone else will know more specifically.

 

EDIT; look about halfway down on this page;

http://64.71.53.59/trannywr.htm#Transmission%20and%20Gears

 

not cheap - maybe someone elses has a similar kit though for less. Or, wrecking yard '06 tranny if you can find one.

 

I dunno

 

 

Carl

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I did read the link. But your explaination here helps to define the fabrication stuff and diffeculty with the mechanicals. But if the rear gear is the same ratio between my car and the donor car then the gearing is not the problem. It sounds like the different axles are the main problem. I dont like the custom axles stuff. I also didnt understand the R160 & the R180. Is this the axle difference in diameter? This sounds like the major show stopper.

 

The link you posted was a swap 5mt to 6mt in a WRX. So I can see that he probably had an eaiser time of the mechanicals. I did not realize that there was a difference with the viscous coupling and the DCCD.

 

OK now to swapping the 5mt with 5mt. Is the viscous coupling a part of the transmission? What other watchouts are there?

 

I appreciate your help and explination. Sounds like you have been there done that?? Thanks Jamal.

 

Mike

 

Mechanically all Subarus are pretty much identical, so many things will swap between cars. The 2nd gen Impreza (02+) and 2nd gen Legacy (95-99) have basically the same chassis (the Legacy is a bit longer). Any transmission/motor combination will physically bolt into pretty much any other car. If you were to take a WRX 5-speed gearbox, I think it would swap in directly and work with your clutch, axles, and rear diff. Or you could use the WRX axles and diff without a problem. There's the issue with pull-type vs push type clutches and I don't know what has which and what it takes to get one to work with a car that had the other type.

 

R180 is the bigger rear diff found on the STi. All the other cars have an R160 (except for 1.8 Imprezas). Axle stubs are different so you can't use R160 axles in an R180. Also I think there are different R160 variations and LSD axles don't work in a non-lsd or something. Anyway I'm pretty sure an MT WRX has a 3.9 rear diff so it's not a problem anyway.

 

The viscous coupling/center diff are integrating into the transmission. So either way, you just attach the prop shaft to the back and it's all there.

 

And actually, since an auto Impreza driveshaft is the right length for a swap into an impreza, it leads me to think an auto Legacy driveshaft would be the right length to put a 6-speed into the Legacy.

 

No, I haven't done this or anything like it really. I just, um, tend to know about things.

 

More than you could ever want to know about dccd and the sti driveline:

http://wrx.dicknogs.net/techdocs/dccd/

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  • 1 month later...
Mechanically all Subarus are pretty much identical, so many things will swap between cars. The 2nd gen Impreza (02+) and 2nd gen Legacy (95-99) have basically the same chassis (the Legacy is a bit longer). Any transmission/motor combination will physically bolt into pretty much any other car. If you were to take a WRX 5-speed gearbox, I think it would swap in directly and work with your clutch, axles, and rear diff. Or you could use the WRX axles and diff without a problem. There's the issue with pull-type vs push type clutches and I don't know what has which and what it takes to get one to work with a car that had the other type.

 

R180 is the bigger rear diff found on the STi. All the other cars have an R160 (except for 1.8 Imprezas). Axle stubs are different so you can't use R160 axles in an R180. Also I think there are different R160 variations and LSD axles don't work in a non-lsd or something. Anyway I'm pretty sure an MT WRX has a 3.9 rear diff so it's not a problem anyway.

 

The viscous coupling/center diff are integrating into the transmission. So either way, you just attach the prop shaft to the back and it's all there.

 

And actually, since an auto Impreza driveshaft is the right length for a swap into an impreza, it leads me to think an auto Legacy driveshaft would be the right length to put a 6-speed into the Legacy.

 

No, I haven't done this or anything like it really. I just, um, tend to know about things.

 

More than you could ever want to know about dccd and the sti driveline:

http://wrx.dicknogs.net/techdocs/dccd/

 

 

the wrx has a front ratio of 3.9 yes, a rear end ratio floats somwhere around a 3.5~3.6 because of somebody's idea of a joke that is a 1.1:1 gear reduction center differential, be safe, whatever transmission you get, get the matching rear end so you don't go binding stuff up and possibly break something and have to respend all the money and time over again...

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