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Old 06-29-2013, 01:05 AM   #1
sconniescoob
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Member#: 161488
Join Date: Oct 2007
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2002 '14 CRV

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Blew this out about two weeks ago. Car had been making a slight whine for a few months. Progressed to a clacking whenever the car was accelerating. Then, taking off from a stop sign (not launching by any means) the damn thing exploded...Wasn't able to get it in before catastrophic failure.





Questions:
1 - thoughts on cause? **** just happens or do I just need to go back to school when it comes to shifting?
2 - anything to prevent this in the future? Anything maintenance wise I should have/could have done?
3 - given the damage, what's the potential that something else in the driveline was damaged? Shop is tearing it down currently.
4 - suitable replacement? I'd like to get another 5 years out of this car and don't want to be in the same boat again.


Mods and model to the left (for those in-app, 2002 wrx, PnP td04, UP, DP, cat back) running Cobb's stage 2 map on 93 oct - we're not looking at serious power here. I don't launch the car or slam gears, but I certainly get on it here and there. Don't track it either. I've got 16 years of driving manuals under my belt, but this is the only one that has been AWD.

Thanks
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Last edited by sconniescoob; 06-29-2013 at 01:14 AM.
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Old 06-29-2013, 09:49 PM   #2
WoodsWagon
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lots of junkers

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Take a close look at the center diff to make sure the rear snap ring didn't pop out. It's a 5" or so dia snap ring and when they come out the end up going through the rear transfer gears. Spring steel snap ring vs hardened gear teeth = no bueno.

The rear transfer housing is pretty isolated from the rest of the transmission. I would have flushed a bunch of brake clean through and out the front drain plug, cleaned the magnet off, and run it. It's an in-car fix at that point because you don't have to pull the trans.

Make sure they know it takes the WRX only 1.1:1 reduction rear transfer gears, not the 1:1 ratio that every other subaru uses. Otherwise you will get bad binding when you try to drive it.

If the snapring didn't cause it, donuts or powersliding from loose surfaces onto pavement can do it. So can vicious launches.
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Old 06-29-2013, 11:45 PM   #3
sconniescoob
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2002 '14 CRV

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Quote:
Originally Posted by WoodsWagon View Post
Take a close look at the center diff to make sure the rear snap ring didn't pop out. It's a 5" or so dia snap ring and when they come out the end up going through the rear transfer gears. Spring steel snap ring vs hardened gear teeth = no bueno.

The rear transfer housing is pretty isolated from the rest of the transmission. I would have flushed a bunch of brake clean through and out the front drain plug, cleaned the magnet off, and run it. It's an in-car fix at that point because you don't have to pull the trans.

Make sure they know it takes the WRX only 1.1:1 reduction rear transfer gears, not the 1:1 ratio that every other subaru uses. Otherwise you will get bad binding when you try to drive it.

If the snapring didn't cause it, donuts or powersliding from loose surfaces onto pavement can do it. So can vicious launches.
Thanks for the input. P&L Motorsports is handling the teardown & rebuild so I'm sure they're on top if the little details. If the rest of the trans is trashed I'll just be going with a LGT replacement.

The snapring hypothesis is interesting. I'll do some more research as that's a new one on me, so thanks. I'll also be curious to here what they have to say. Like I said, no launches of any real note (2k maybe on a tare and certainty no power sliding, donuts etc. A little mysterious. But I am the 3rd owner, so no telling what sort of life it led before me. Thanks.
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Old 07-15-2013, 02:41 PM   #4
sconniescoob
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Join Date: Oct 2007
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Vehicle:
2002 '14 CRV

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Quote:
Originally Posted by WoodsWagon View Post
Take a close look at the center diff to make sure the rear snap ring didn't pop out. It's a 5" or so dia snap ring and when they come out the end up going through the rear transfer gears. Spring steel snap ring vs hardened gear teeth = no bueno.

The rear transfer housing is pretty isolated from the rest of the transmission. I would have flushed a bunch of brake clean through and out the front drain plug, cleaned the magnet off, and run it. It's an in-car fix at that point because you don't have to pull the trans.

Make sure they know it takes the WRX only 1.1:1 reduction rear transfer gears, not the 1:1 ratio that every other subaru uses. Otherwise you will get bad binding when you try to drive it.

If the snapring didn't cause it, donuts or powersliding from loose surfaces onto pavement can do it. So can vicious launches.
You win the prize - snapring failure. Impressive diagnosis. Major carnage...could have done without the rebuild.
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Old 07-15-2013, 03:12 PM   #5
WoodsWagon
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lots of junkers

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I've seen it before and it's more common than you'd think. Here's a thread on it: http://forums.nasioc.com/forums/show....php?t=2432712

Last edited by WoodsWagon; 07-15-2013 at 03:27 PM.
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Old 07-15-2013, 06:17 PM   #6
Kelsee.mcanally
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Will it cause the car not to go into gear?
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Old 07-15-2013, 07:02 PM   #7
sconniescoob
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2002 '14 CRV

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Quote:
Originally Posted by WoodsWagon View Post
I've seen it before and it's more common than you'd think. Here's a thread on it: forums.nasioc.com/forums/showthread.php?t=2432712
Interesting. The visual helps explain why it was making noise, but not much. It was barely audible on normal conditions....except when it let go.

Edit: I guess this explains the rather loud "pop" I had earlier this year. We had sub-zero temps and just attributed it to the cold weather. Likely transfer gears eating themselves.

Quote:
Originally Posted by Kelsee.mcanally View Post
Will it cause the car not to go into gear?
Probably depends on if it destroys the gear set itself. In my case it "only" took the output shaft. Even after it went I never had issues getting it in gear but I, obviously, couldn't get power down.

Last edited by sconniescoob; 07-15-2013 at 07:18 PM.
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