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I am in the process of replacing the center diff unit on my 2011 2.5i OB 6MT due to a bad viscous coupler. I watched a number of videos and read forums that detailed this process. After removing the diff housing I am able to see the center diff unit, but am not able to remove it. I was able to get a good grip on it, but it wont budge. In the videos, it appears to slide out with no issue. I have a newer model than the model being worked on in the video, but thought most of the same principles would still apply...which they did until I was unable to remove the center diff unit. Before anyone asks, the gearbox is in neutral. Anybody have a similar experience with this or thoughts on how to get it out?
 

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2005 OBXT Limited, VF37, STI intake, 5MT
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Do you have a picture of your current step/progress?

The center diff should just slide right out. You might need to rock the front wheels/axles to loosen the splines from the front of the center diff.
 

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2000 Outback Limited, Dual Range 5 Speed
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That looks totally different to the gen 2 setup, don’t have that shaft coming out of the center differential. I hope you get it moving but sorry can’t help with your predicament.
 

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That looks totally different to the gen 2 setup, don’t have that shaft coming out of the center differential. I hope you get it moving but sorry can’t help with your predicament.
Good spotting that.

Looks as if it's the shaft from the transfer driven gear is stuck in the center differential.

I wonder what the symptoms were that led to this work. If no drive to the rear, then that could be explained by the transfer driven gear having separated from its shaft. However, the shaft should slide out of the differential. (See https://parts.subaru.com/a/Subaru_2011_Outback-Base-25L-6MT/_80160_6027583/MT--TRANSFER--EXTENSION-EXTENSION/B14-121-02.html )

If there were symptoms of torque bind (leading to mention of "a bad viscous coupler"), that, and the current difficulty, could also be explained by the shaft being seized in pilot bearing in the front drive side gear. In this case, the seized bearing would have been the cause of torque bind and that might also have caused the transfer drive gear to separate from its shaft. Nevertheless, even with the drive gear shaft stuck in the front side gear it should be possible to slide the differential out (the front side gear comes with the differential). But there might also be related damage at that far end. The transmission counter shaft that is splined to, and drives, the differential case, could also be seized into the case. That would prevent the differential from sliding out. Or, the front bearing, that is pressed onto the differential case might be seized in the transmission case.

Attached are some slides from a center differential tear-down presentation I made a few years ago that should be available through my thread https://www.subaruoutback.org/forums/66-problems-maintenance/216090-manual-tranny-center-differential-dissassembly-incl-viscous-coupler-slideshow.html (See post #16 for updated access info.) It's from a different transmission, but should provide some idea of what might be happening.

(EDIT: Looked at breakout diagrams of the 5 and 6 speed and the instructions for removing the center differential. There are differences in the center differential, e.g., the 6 speed differential case doesn't have the long, narrower extension that goes forward into the transmission. In addition, the shaft on the transfer drive gear in the 5 speed is long whereas it appears short in the 6 speed. [Perhaps the shaft in the differential is some sort of pilot support for the transfer drive gear shaft. Does the transfer drive gear slide easily on the shaft; are there any bearings that run between the drive gear shaft and the shaft in the differential?] However, as far as removal is concerned, there doesn't appear to be any difference in the FSM instructions. Breakout diagrams attached.)
 

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Discussion Starter #6
Wow, thanks for such a detailed response! Unfortunately I conceded defeat and ended up brining it in to a shop - from what they told me, the front bearing seized. They ended up having to remove the whole transmission to get it out. Definitely not the outcome I wanted, especially after getting to what was supposed to be the halfway point in the project... Anyway, thanks again for the great response, much appreciated!
 

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Good observation, yeah most of the photos/videos I have seen have been from older gens - I didn't expect it to be so different. Thanks for the reply!
 
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