I figure that somebody here must have a rear differential sitting around on a workbench, in particular, one that will be similar to a Forester diff. If so, could you measure the thread size for the little breather that is mounted on top of the diff housing?

 

The breather looks like a small thimble on top, with a hex base for using a wrench on it. I'm guessing it is a tapered pipe thread, but I need to know the thread size.

 

Yes, I'm rigging a diff breather extension, and I have a line on a 90* angle fitting that I think might work. I'd like to just drop the diff once to install it, rather than twice (once to measure, and a 2nd time to install it).

I just got under the car today looking for that damn breather. I couldn't find it since I was not about to drop the diff. just so I could look at it. If anybody could post pics it would be greatly appreciated. I don't understand why I couldn't at least see or feel a tube on top??

I just got under the car today looking for that damn breather. I couldn't find it since I was not about to drop the diff. just so I could look at it. If anybody could post pics it would be greatly appreciated. I don't understand why I couldn't at least see or feel a tube on top??

I can barely see the top of it, and once you spot it, you can reach up there to feel it. But it seemed impossible to get a wrench in there to take it off. On the Forester, it is visible from behind, and it is slightly to the left of center. It is the only thing sticking up on the top of the diff, directly in front of the rear cover.

The breather isn't threaded at all, it is just a push in style. Here are the details:

http://www.subaruforester.org/vbulletin/forums/showpost.php?p=75169&postcount=7

Sweet thanks, but how would you add a line to that. Just take off the top cap and hose clamp a line to it?

I'm a little concerned about having a line attached to it, since it could easily pull out the fitting. I've gotta give it some thought, and see what else is available for a fitting.

Ideally...you would want to remove the diff cover and then tap some pipe threads into the port so you can add a barbed fitting to it.

 

Trying to waterproof it for offroading?

 

 

Jay Storm

Ideally...you would want to remove the diff cover and then tap some pipe threads into the port so you can add a barbed fitting to it.

 

Trying to waterproof it for offroading?

Yep, that is what I'd like to do in order to get a secure attachment. It'll take more than removing the cover, because to get access to the top with the tap, the diff needs to be dropped 6" or so. A few weeks ago I looked at the differntial mounts and it shouldn't be too hard to do. An alternative would be to drill a hole through the sheet metal from the rear luggage area, to allow direct access to the top of the diff. Should be able to get a hole plug that would fit to seal it back up.

 

Toyota has a diff breather extension with a hose fitting that is at 90 degree angle that should work. It is toyota part number 90404-51026 for about $4.