Subaru Forester Owners Forum banner
1 - 20 of 28 Posts

·
Registered
2012 Forester Manual
Joined
·
61 Posts
Discussion Starter · #1 · (Edited)
I have a 2012 Forester X with 156k miles with 5 speed manual

At around 145K miles the input shaft bearing failed, it toasted the input shaft itself so a rebuild was unrealistic.
So I replaced it with a used trans with 78K miles

Five months later ... I can hear the input shaft bearing has begin to fail on this one also.

My question is ... Is this just bad luck on the second trans. Or is there something I could be doing to contribute to the failure. Or something mechanically wrong outside the transmission that could be causing excess wear?
I dont mind trying again but 5mt transmissions for this year range arent cheap and its not worth it to get only 5 months out of a trans.
 

·
Registered
2012 Forester Manual
Joined
·
61 Posts
Discussion Starter · #3 ·
Yep, I always keep the level just a hair above full, checked at every oil change
 

·
Registered
2012 Forester Manual
Joined
·
61 Posts
Discussion Starter · #5 ·

·
Registered
2010 X Limited, 2.5L NA, 4AT. Purchased as the second owner in 2020 with ~126K miles.
Joined
·
313 Posts
I don't know. Is everything aligned? Are all mounts in place and intact? Bolts torqued? Make sure nothing can shift out of place under there.
 

·
Registered
2017 Forester Premium 2.5i, 6-speed manual, moon-roof, fog lights, skid-plates, winch, 2nd bedroom
Joined
·
152 Posts
If you replace the bearing now, would you be able to save the the input shaft?
Seems like low miles for your transmission, but miles often evaporate off used parts.
Being the owner of a manual transmission with 40k miles, I hope it can get 350k miles.
 

·
Registered
2012 Forester Manual
Joined
·
61 Posts
Discussion Starter · #10 ·
If you replace the bearing now, would you be able to save the the input shaft?
Seems like low miles for your transmission, but miles often evaporate off used parts.
Being the owner of a manual transmission with 40k miles, I hope it can get 350k miles.
I have a new (used) trans being shipped as we speak. Hopefully it can get here in time to remove the current trans before any serious damage is done. Then maybe I will get the bearing replaced and have a back up trans to keep on hand
 

·
Registered
2010 X Limited, 2.5L NA, 4AT. Purchased as the second owner in 2020 with ~126K miles.
Joined
·
313 Posts
Let's not forget this is the third transmission to be installed in the automobile. There might be an underlying condition that needs to be addressed. Check everything twice, even if it's something you never thought needed to check.
 

·
Registered
2012 Forester Manual
Joined
·
61 Posts
Discussion Starter · #12 ·
Let's not forget this is the third transmission to be installed in the automobile. There might be an underlying condition that needs to be addressed. Check everything twice, even if it's something you never thought needed to check.
Cant seem to find any good source on what factors outside of a bad trans itself could be the culprit.
 

·
Registered
2010 X Limited, 2.5L NA, 4AT. Purchased as the second owner in 2020 with ~126K miles.
Joined
·
313 Posts
I can understand that the initial transmission failed but the fact that the second transmission failed in the same way indicates something is wrong. It's looking like the third transmission will probably fail in the same way. Unless you are driving in some otherworldly manner, something is not right with the assembly. That's my observation and opinion. I'm recommending that extra care be taken at every step of the installation. I would verify all mating surfaces are clean, flat, square, and unmarred. Check around every bolt hole, looking for deformation. If there are alignment pins, be sure they are set square. I note in my 2010 manual, there is a special tool that is used to tilt the engine when the transmission is being removed and installed. You should probably do that. I would also install new rubber mounts in case there is degradation of those parts.

I think you really have to go at it thinking, "What is wrong, here"? Rather than just pull the old tranny and pop in the new one. Unless, of course, you just like changing transmissions. :LOL: Nothing wrong with that. :)
 

·
Registered
2012 Forester Manual
Joined
·
61 Posts
Discussion Starter · #14 ·
I can understand that the initial transmission failed but the fact that the second transmission failed in the same way indicates something is wrong. It's looking like the third transmission will probably fail in the same way. Unless you are driving in some otherworldly manner, something is not right with the assembly. That's my observation and opinion. I'm recommending that extra care be taken at every step of the installation. I would verify all mating surfaces are clean, flat, square, and unmarred. Check around every bolt hole, looking for deformation. If there are alignment pins, be sure they are set square. I note in my 2010 manual, there is a special tool that is used to tilt the engine when the transmission is being removed and installed. You should probably do that. I would also install new rubber mounts in case there is degradation of those parts.

I think you really have to go at it thinking, "What is wrong, here"? Rather than just pull the old tranny and pop in the new one. Unless, of course, you just like changing transmissions. :LOL: Nothing wrong with that. :)
I hear you. But people slap Subaru transmissions in and out all the time without special removal tools ... this is the first im hearing of it ... ill look into it.
The transmission mount is new since I sheared a stud off the old one first time I pulled the tranny, I guess I could try to replace the cross-member bushings but that doesn't seem like they could create an issue. The pitch stop mount is new. I guess I could try the engine mounts .. but im skeptical about that being a factor.

My logic would say that once the engine and trans are mated together, external mounts and bushings shouldnt be to put damaging force on the input shaft. Only thing I could think is that if the crank were somehow moving or out of alignment it could put wear on the shaft but I would assume I would have other more obvious issues going on f there were crank issues.
 

·
Registered
2010 X Limited, 2.5L NA, 4AT. Purchased as the second owner in 2020 with ~126K miles.
Joined
·
313 Posts
@Sleezer1533, whatever works for you. Two identical failures. Something isn't right, in my opinion. What does the bearing and shaft look like? is there an indication of unusual wear at one position or another? Right, yes. People slap transmissions all the time but they don't have multiple identical failures. I can't explain it. I was going to say in the last post that the parts should slip together easily. If you have to muscle the parts together, something isn't right. Engine tilt at assembly could explain that.
 

·
Registered
2012 Forester Manual
Joined
·
61 Posts
Discussion Starter · #16 ·
@Sleezer1533, whatever works for you. Two identical failures. Something isn't right, in my opinion. What does the bearing and shaft look like? is there an indication of unusual wear at one position or another? Right, yes. People slap transmissions all the time but they don't have multiple identical failures. I can't explain it. I was going to say in the last post that the parts should slip together easily. If you have to muscle the parts together, something isn't right. Engine tilt at assembly could explain that.
Yes, as you've said many times ... multiple failures ... that's been established
But the car needs to be drivable, I cant just take the car off the road and scratch my balls staring at it hoping an answer will just appear out of thin air.
 

·
Registered
2010 X Limited, 2.5L NA, 4AT. Purchased as the second owner in 2020 with ~126K miles.
Joined
·
313 Posts
@Sleezer1533, Yes. I see. Have you still got the old transmission laying around where you could look at the bearing? I mean was it disintegrated?

You identified the fault as a bearing failure. Something caused the bearing to fail. If it was being properly lubricated, there has to be a mechanical stress causing the failure.

Okay. So up your game when you install the next transmission. Clean, tight, properly torqued, all aligned. All that kind of thing to give you the best chance of success. If you can see a cause under close scrutiny, you can fix it.

Apparently, a specific cause of this kind of failure is not known among the participants here.
 

·
Registered
2012 Forester Manual
Joined
·
61 Posts
Discussion Starter · #18 ·
@Sleezer1533, Yes. I see. Have you still got the old transmission laying around where you could look at the bearing? I mean was it disintegrated?

You identified the fault as a bearing failure. Something caused the bearing to fail. If it was being properly lubricated, there has to be a mechanical stress causing the failure.

Okay. So up your game when you install the next transmission. Clean, tight, properly torqued, all aligned. All that kind of thing to give you the best chance of success. If you can see a cause under close scrutiny, you can fix it.

Apparently, a specific cause of this kind of failure is not known among the participants here.
According to the shop who tore down the original trans, the bearing failed enough to cause it lock and to spin on the shaft causing the inner race to "weld" itself to the shaft, thats why the old trans was not rebuilt as the input shaft could not be saved.
Ive looked at the shaft myself, and its the rear most bearing, the big chunky one. you can spin it by hand but it pretty rough, can also see the "welding" that the shop talked about
I will say that the noise is different this time, still all signs pointing at input shaft bearing but not the same ... similar ... but not the same as last time
Wont know until the tran is opened up, but maybe uts just one of the needle bearings on the shaft this time.
 

·
Registered
2010 X Limited, 2.5L NA, 4AT. Purchased as the second owner in 2020 with ~126K miles.
Joined
·
313 Posts
Okay, thanks. Spun bearing. I've looked at this about a dozen ways. I doubt the second transmission will have a spun bearing on the main input shaft. So the bearing locked up one day and spun on the shaft. Not necessarily a repeated event. That's what you are looking at. This bearing is way in there and on the middle of that shaft. Just put the new transmission in with due care and you should be good. Tranny #2 might just have a noisy throw out bearing or something like that.
 
1 - 20 of 28 Posts
Top