04 wrx sheared input shaft. Options?

Gohawks688 · 01-22-2021, 11:37 PM

Howdy guys. New on here looking for help/advice on a repair for my wife's 04 wrx. It lost the use of 3/4/5 gears a while back and was parked. After pulling the trans and splitting the case the input shaft is sheared. I am looking for advice on options moving forward.
Here's what I think my options are....
1. Get a jdm trans and swap. Pretty simple much to that. Not sure on who reputable importers are and don't really want to drop 1200 on a car that's worth 5k.
2. Find a used local 5mt and swap in. I've found the cross reference charts and I know about push vs pull clutch and final drive differences.
3. Buy a local push clutch trans (forester and legacy trans seem to be much cheaper) and split the case and put those gears into my pull case. Is the difference in push vs pull trans all in the case/bell housing and clutch fork? My assumption is that the internals are the same and can be swapped? Now the million dollar question can a handy diy guy swap shafts from case to case? I know I can physically do it but will not measuring gear lash / proper shimming end up biting me? Anyone successfully done this?

Thanks in advance guys! If I can figure out a way to post pics I will show you my sheared shaft!

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GeoNV · 01-23-2021, 01:27 AM

If the 04 is like the 2011 trans I took apart I’d hazard a guess that you could swap the input shaft and gears without changing the shims and all that. The pinion shaft would be a different story. You’d have to make sure it was the same gear ratios and also that the speedometer sensor type was the same. Obviously measure the various components and then make sure everything meshed properly.

I don’t know if the parts would interchange or not, just looking at the photos of mine when it was apart I’d wager a guess you’d be ok.

Gohawks688 · 01-23-2021, 01:34 AM

Quote:

Originally Posted by GeoNV

If the 04 is like the 2011 trans I took apart I’d hazard a guess that you could swap the input shaft and gears without changing the shims and all that. The pinion shaft would be a different story. You’d have to make sure it was the same gear ratios and also that the speedometer sensor type was the same. Obviously measure the various components and then make sure everything meshed properly.

I don’t know if the parts would interchange or not, just looking at the photos of mine when it was apart I’d wager a guess you’d be ok.

I've considered two options on the gear swap front. Get a push type trans and take all the internals (input&output shafts whole, diff ect) and put in the wrx case.
Or
Source a new input shaft and move all my current gears over to that new shaft. I've seen input shaft for about 150 new online. Do the gears just side off once the nut is taken off or are they pressed? If I keep the exact same shims and use an the same gears I'm thinking it would be ok. Seems like a risk worthy of 150$ and some tinker time.
But my fear is the same as yours. That without proper shimming and measurement things will go bad.

Unabomber · 01-23-2021, 10:09 AM

You are hung up on the push/pull concept when you should really be looking at the axle differences as the push/pull differences didn't start until 06 I think. Your current trans will either have stub or stubless axles depending on your build date as it changed mid year.

If you have to ask if the average man can do a swap, the answer is no. If you are an OG or skilled with transmissions, yes. You'd have the ~$100 SOA alignment tool and/or be an OG and do it with gear paint and read the lash with your eyes.

Where do you live? I know every Subaru transmission shop worth a damn in America and I can point you to the closest. Otherwise, get the gears and see if AAMCO or local trans shop can do it for you. Use 04 or 05 WRX gears, new or used. Might as well swap out all the synchros too.

04 guts: https://www.ebay.com/itm/2004-SUBARU...S/293752672653

Gohawks688 · 01-23-2021, 11:31 AM

Quote:

Originally Posted by Unabomber

You are hung up on the push/pull concept when you should really be looking at the axle differences as the push/pull differences didn't start until 06 I think. Your current trans will either have stub or stubless axles depending on your build date as it changed mid year.

If you have to ask if the average man can do a swap, the answer is no. If you are an OG or skilled with transmissions, yes. You'd have the ~$100 SOA alignment tool and/or be an OG and do it with gear paint and read the lash with your eyes.

Where do you live? I know every Subaru transmission shop worth a damn in America and I can point you to the closest. Otherwise, get the gears and see if AAMCO or local trans shop can do it for you. Use 04 or 05 WRX gears, new or used. Might as well swap out all the synchros too.

04 guts: https://www.ebay.com/itm/2004-SUBARU...S/293752672653

I am not an oh transmission guy but I am an engineer And am pretty darn handy.
I am concerned over many things haha. I don't want to swap a push case into my pull car. Don't want to worry about getting new fly wheel, clutch slave ect. Push pull may not be an issue till 06 in wrx but most forester and legacy are push type and those trans are super cheap in my area compared to wrx parts.
My case has the male stub axles in the trans and the female axles.
To answer your question I am in western washington.
I have seen the guts you listed on eBay. But that still puts me in the same spot of can I also slap those in myself or do I send it to a shop? I'd prefer not to do that as I am a do it yourself kinda guy. (Don't get me wrong I know there are times when a guy like me doesn't have the right skills and this may be one of them. That's why Im on here doing the research.) None of the local shops I've called have wanted to touch the trans since I pulled it from the car.

Do you have any experience with the jdm import trans?

Maybe a little more information on the. Ar and what I want to do with it will help
It's got 180k on it. Original everything. It's a DD not a track car. No intention of crazy power numbers. Just want to get it back on the road and enjoy it.
Thanks for your input!

Unabomber · 01-24-2021, 09:40 AM

A JDM transmission is more dramatical. Will the front and center differential ratios be right for your rear differential? If you want a whole swap option, an 04/05 WRX trans that fits your axles is the best plug and play option. You could also do an 02/03 but those are a tiny bit weaker.

If you contact https://www.facebook.com/getadomtune he can probably either do the work himself or refer you to a shop. He may also have or know of good trans sources. Tell him Big Ron sent ya and that he loves him.

01-22-2021, 11:37 PM	#1
Gohawks688 Scooby Newbie Member#: 521322 Join Date: Dec 2020	04 wrx sheared input shaft. Options? Howdy guys. New on here looking for help/advice on a repair for my wife's 04 wrx. It lost the use of 3/4/5 gears a while back and was parked. After pulling the trans and splitting the case the input shaft is sheared. I am looking for advice on options moving forward. Here's what I think my options are.... 1. Get a jdm trans and swap. Pretty simple much to that. Not sure on who reputable importers are and don't really want to drop 1200 on a car that's worth 5k. 2. Find a used local 5mt and swap in. I've found the cross reference charts and I know about push vs pull clutch and final drive differences. 3. Buy a local push clutch trans (forester and legacy trans seem to be much cheaper) and split the case and put those gears into my pull case. Is the difference in push vs pull trans all in the case/bell housing and clutch fork? My assumption is that the internals are the same and can be swapped? Now the million dollar question can a handy diy guy swap shafts from case to case? I know I can physically do it but will not measuring gear lash / proper shimming end up biting me? Anyone successfully done this? Thanks in advance guys! If I can figure out a way to post pics I will show you my sheared shaft! * Registered users of the site do not see these ads.

01-23-2021, 10:09 AM	#4
Unabomber 👏 Big Ron 👏 Moderator Member#: 18062 Join Date: Apr 2002 Chapter/Region: MAIC Location: I can save you a ton of cash Vehicle: on car parts so PM me b4 j00 buy	You are hung up on the push/pull concept when you should really be looking at the axle differences as the push/pull differences didn't start until 06 I think. Your current trans will either have stub or stubless axles depending on your build date as it changed mid year. If you have to ask if the average man can do a swap, the answer is no. If you are an OG or skilled with transmissions, yes. You'd have the ~$100 SOA alignment tool and/or be an OG and do it with gear paint and read the lash with your eyes. Where do you live? I know every Subaru transmission shop worth a damn in America and I can point you to the closest. Otherwise, get the gears and see if AAMCO or local trans shop can do it for you. Use 04 or 05 WRX gears, new or used. Might as well swap out all the synchros too. 04 guts: https://www.ebay.com/itm/2004-SUBARU...S/293752672653 Last edited by Unabomber; 01-23-2021 at 10:14 AM.

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01-23-2021, 01:27 AM	#2
GeoNV Scooby Newbie Member#: 518830 Join Date: Sep 2020 Chapter/Region: RMIC Location: Colorado Vehicle: 2009 WRX dark grey metallic	If the 04 is like the 2011 trans I took apart I’d hazard a guess that you could swap the input shaft and gears without changing the shims and all that. The pinion shaft would be a different story. You’d have to make sure it was the same gear ratios and also that the speedometer sensor type was the same. Obviously measure the various components and then make sure everything meshed properly. I don’t know if the parts would interchange or not, just looking at the photos of mine when it was apart I’d wager a guess you’d be ok.

01-24-2021, 09:40 AM	#6
Unabomber 👏 Big Ron 👏 Moderator Member#: 18062 Join Date: Apr 2002 Chapter/Region: MAIC Location: I can save you a ton of cash Vehicle: on car parts so PM me b4 j00 buy	A JDM transmission is more dramatical. Will the front and center differential ratios be right for your rear differential? If you want a whole swap option, an 04/05 WRX trans that fits your axles is the best plug and play option. You could also do an 02/03 but those are a tiny bit weaker. If you contact https://www.facebook.com/getadomtune he can probably either do the work himself or refer you to a shop. He may also have or know of good trans sources. Tell him Big Ron sent ya and that he loves him.