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Discussion Starter #1
Today I noticed 1st and second gears were hard to get into when sitting still with the clutch in. 3rd grinded twice on me despite the clutch being to the floor. Now it may be a non issue, but lets say the trans is going....

Could I put in a 6 speed manual into my 2000 Outback with the EJ25 motor? I'm already running a 5 speed manual and am wondering if there are mileage improvements if I switch to the 6 speed. In theory it would be pull one trans out, put another one in and thats it. Is the STI my only option for a 6 speed trans?

What are my other options as far as changing the transmission with other Subaru models? I do not and I repeat do not want to go with an auto trans. I refuse to ever own an auto car unless I intend to flip it for money or the auto trans is the only option the car has. I can't drive auto trans cars without having problems.
 

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Discussion Starter #2
Really, no one knows? I am wondering about a trans swap on a manual. Or am I in the wrong forum section for this?
 

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give it some more time. you might also search at NASIOC.

I suspect - due to the center diff in the 6spd and maybe the bringing over the rear diff due to different final ratios (anyone?) too, it's gonna be a bigger project than you might think.
 

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you can swap a 5 to a 6 speed from a sti, but the gear ratio would not match the power output to make it worth it( n/a vs the tubro from the sti)... plus to use the 6 speed tranny you would also need the matching rearend, the cv axles and drive shaft...
 

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yes, you can do anything you want with enough time, skills, or money.
6 speed swaps are not rare so you can google it and find out.

also - number of gears does not translate to gas mileage, the 6 speed transmission was hardly designed for that - it was meant for performance and track racing. i'm not into performance but i believe more gears allows you to more precisely drive - being in exactly the right rpm for power availability - something that is hardly a concern for daily driving.

the final drive gear of the highest gear matters for highway mileage. if 6th gear times the final drive ratio of one trans equals the same as 5th gear of the other times it's final drive ratio then there's no gains. you can't retain your final drive ratio or mix and match those due to the integrated front differential on Subaru transaxles. well one *can* swap front diffs but you won't be getting into that.

there are lots of transmission lists out there with gear ratios - you'll want to calculate your 5th gear ratio and final drive and compare them to the 6 speed transmission 6th gear ratio and final drive to see if there's a difference (and some 6 speeds also have a 1.1 transfer gear set you'll have to incorporate into the calculations as well).

i don't really get into particulars like this but from a purely final drive ratio aspect i believe there are some 6 speed transmissions that turn more RPM's for the same given speed in the highest gear as compared to 5 speeds - so there would be no mileage gains.

not sure if they're all like this but the ones i'm familiar with have DCCD so you'll have some wiring work to get that function out of it...which i would think you'd go for given the price of these transmissions - they are very expensive.
 

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^What he said. The 6th gear in STi transmission is not an overdrive, it is actually a shorter gear than your 5th. Those cars get terrible mileage, city and highway.

You're looking at an easy three grand to swap one, for no real benefit. Now if you were swapping an entire STi drivetrain, that's a different story.
 

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Discussion Starter #7
Ah I see. Alright, so there are no benefits to just swapping the trans. I did such a swap with my Trans Am, going from a 5 speed to a 6 speed with a .50 6th gear ratio. That is a pure highway mileage cruising gear. I guess that is not the case here with the Subaru transmissions. More proof that newer cars are more complicated than older ones. I could run a 4.11 rear gear in the Trans Am and still get 25 on the highway with that trans.

When I drove the outback last night it seemed to be just fine. So I don't know what was the cause of the wonky behavior of it earlier in the day. Even if I did find a wrecked STI I would just as soon swap that drivetrain into an impreza. And for the price of doing such a swap I could get a typical WRX in good shape that has 8/10s the performance of the STI. As it stands now, if I sold a car I picked up to flip, I would either get another daily driver or finish the one project. If I got a newer daily driver, the Outback will be for winter and hauling duty. Not sure what I would get for a daily, but it could be anything from a older Miata to a new BRZ.
 

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I suppose, for the right amount of money, anything is possible.

Like the saying goes "you can build a dam anywhere on the river for the right price!"
 

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When I drove the outback last night it seemed to be just fine. So I don't know what was the cause of the wonky behavior of it earlier in the day.
Maybe the floor mat slipped up causing the clutch to not fully release? Maybe the clutch is worn and soon to need replacement? Whole lot of things that don't foretell of an impending transmission failure.
 

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Yes 6 speed can be done to an Outback and half the people in this thread are ignorant of the RPM outcome and how you do it.

I have a 2008 STI 6 speed in my 2005 Outback XT.

On the highway with stock 225x55x17 tires it turns 2600 RPM

I am now running 245x45x18 STI wheels which are the exact same diameter as the stock wheels and tires.

It pretty much bolts right in with the correct parts.

STI 6 speed
4EAT (4 speed auto) legacy driveshaft
R180 STI rear end
6 speed rubber mount
spec b rear diff mount
spec b rear axels
spec b shifter or 2008 up STI shifter

I love it one of the best mods I have done.

legacygt.com NSFW 6 speed swap thread is the best of about 3 swap threads
http://legacygt.com/forums/showthread.php/nsfws-6mt-swap-thread-143520.html

Here is the thread on my car with updated pics at the end of the thread:
http://legacygt.com/forums/showthread.php/2005-stage-3-outback-xt-sti-seats-150039.html
 

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Your descriptions of symptoms indicate a clutch problem, not a transmission problem. The clutch is not fully releasing. You could have a leak in the clutch hydraulic system, air in the system, or a failing master or slave cylinder. None of these is particularly difficult to fix. Swapping transmissions is several orders of magnitude more difficult. Good luck.
 

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Yes 6 speed can be done to an Outback and half the people in this thread are ignorant of the RPM outcome and how you do it.

I have a 2008 STI 6 speed in my 2005 Outback XT.

On the highway with stock 225x55x17 tires it turns 2600 RPM
Please enlighten us on your final gear ratio compared to the stock on your 5spd. The numbers I've seen still have the same final gear ratio, just closer gears in between.

My LGT would cruise on the highway around 2600 rpm.
It pretty much bolts right in with the correct parts.
Which is what the "ignorant" people here said. But for the extra money in parts to swap it, the mpg improvement will be nill, or so miniscule that you will neve recoup the cost.

Now if you're going full blown STi swap, that's a whole other story.

The OP was asking if it was a simple swap and if it would yield good enough mpg to be worthwile. Both of those are a big fat NO
 

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Please enlighten us on your final gear ratio compared to the stock on your 5spd. The numbers I've seen still have the same final gear ratio, just closer gears in between.

07 + STI 6 speed 6th gear 0.756
05 Outback XT 0.738

The kicker is the Outback is a 4.44 rear end and the STI is a 3.90 so at 70 MPH in the Outback you will be near 3k and at 70 MPH with the 6 speed in the Outback with same size tires you are at 2600

Also I might add that you lose nothing down low because the first few gears in the STI transmission are lower than the outback so when you multiply the gear ratio of the transmission by the rear end ratio the STI tranny is the same or lower in the first few gears. You have to do the math and look at FINAL drive ratio, gear ratio and tire diameter not just the 5th or 6th gear ratio. I am running the stock diameter tire at 245x45x18 (same as 225x55x17), 08+ STI 6 speed with .756 times the 3.90 final drive so YES my RPM is lower and my milage has went up. I might also add that at the RPM I am running it is the same in 6th as a spec B 6 speed which has more of an overdrive in 5th and 6th than the STI 6 speed. The difference is I am running stock diameter tires/wheels so I end up with the same RPM in 6th as a spec b with lower profile tires/wheels

My LGT would cruise on the highway around 2600 rpm.
At what speed?


Which is what the "ignorant" people here said. But for the extra money in parts to swap it, the mpg improvement will be nill, or so miniscule that you will neve recoup the cost.

Ok sorry for the ignorant statement, I meant no harshness. Ignorant is a word people take wrong. I meant they just are not looking at all the data so they are lacking knowlege

Now if you're going full blown STi swap, that's a whole other story.
When you say full blown STI swap what are you referring to?

The OP was asking if it was a simple swap and if it would yield good enough mpg to be worthwile. Both of those are a big fat NO
Really have you done the swap and experienced the mileage differences? With the proper parts I listed the swap is a piece of cake. I am running over 350 WHP with 1000 CC injectors and the best Mileage I got was 28-29 with NON ethanol 93 from Chicago to Detroit, cruising at 70-75 MPH
 

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Remember though that you have a 2005 XT the OP just has a 2000 N/A ej25 so it already is different for you and the OP will have different results
 

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Really have you done the swap and experienced the mileage differences? With the proper parts I listed the swap is a piece of cake. I am running over 350 WHP with 1000 CC injectors and the best Mileage I got was 28-29 with NON ethanol 93 from Chicago to Detroit, cruising at 70-75 MPH
The fact that you have to state "with the proper parts" means it's not simple or cheap. I'm not arguing that it can't be done, just that it's not a single day, buy a new tranny and be done type of deal. Like swapping in a new/used MT from another '00 OB would be.

No, I haven't done the swap. Neither have you on a '00 OB. And I could get 29-30 mpg in my LGT with a 5spd cruising 70-75 MPH on I-40 across NC. But that doesn't really mean anything to the OP and his situation.
 

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The fact that you have to state "with the proper parts" means it's not simple or cheap. I'm not arguing that it can't be done, just that it's not a single day, buy a new tranny and be done type of deal. Like swapping in a new/used MT from another '00 OB would be.

No, I haven't done the swap. Neither have you on a '00 OB. And I could get 29-30 mpg in my LGT with a 5spd cruising 70-75 MPH on I-40 across NC. But that doesn't really mean anything to the OP and his situation.
:rolleyes:
 

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Yes 6 speed can be done to an Outback and half the people in this thread are ignorant of the RPM outcome and how you do it.

I have a 2008 STI 6 speed in my 2005 Outback XT.

On the highway with stock 225x55x17 tires it turns 2600 RPM

I am now running 245x45x18 STI wheels which are the exact same diameter as the stock wheels and tires.

It pretty much bolts right in with the correct parts.

STI 6 speed
4EAT (4 speed auto) legacy driveshaft
R180 STI rear end
6 speed rubber mount
spec b rear diff mount
spec b rear axels
spec b shifter or 2008 up STI shifter

I love it one of the best mods I have done.

legacygt.com NSFW 6 speed swap thread is the best of about 3 swap threads
Subaru Legacy Forums

Here is the thread on my car with updated pics at the end of the thread:
http://legacygt.com/forums/showthread.php/2005-stage-3-outback-xt-sti-seats-150039.html
Sorry for digging up an old thread but I cannot find what I'm looking for anywhere. How did you get the 4EAT Legacy driveshaft to mate up with the STi R180 differential input/companion flange? The Legacy 4EAT has an R160 diff, which has a smaller bolt pattern on the diff companion flange than the STi R180. Did you put an R160 companion flange on the R180 diff? This supposedly can be done. Or did you drill a smaller bolt pattern in the R180 companion flange? The way your post reads it implies that you just bolted the Legacy 4EAT driveshaft right up the STi R180 diff.

Thank you
 

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Sorry for digging up an old thread but I cannot find what I'm looking for anywhere. How did you get the 4EAT Legacy driveshaft to mate up with the STi R180 differential input/companion flange? The Legacy 4EAT has an R160 diff, which has a smaller bolt pattern on the diff companion flange than the STi R180. Did you put an R160 companion flange on the R180 diff? This supposedly can be done. Or did you drill a smaller bolt pattern in the R180 companion flange? The way your post reads it implies that you just bolted the Legacy 4EAT driveshaft right up the STi R180 diff.

Thank you
It is discussed in the 6 speed thread that I placed the link to, with that said you put the R160 Yoke on the R180 and bolt up the driveshaft. :)
 

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Thanks! That's the route I'm taking. My neighbor is saying that when I change the flange I'll also have to replace a crush sleeve on the pinion shaft to make sure the gears in the diff mesh properly. Is he correct? Did you have to anything like that when you did yours?

Thank you!
 
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