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2003 GLX Sedan, 2003 GLX 4motion Wagon
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Discussion Starter · #1 · (Edited)
I just recently purchased a 2003 4motion wagon with a bunch of issues. I was told it had a bad transmission, "it started slipping a few days ago". Come to find out there was just a hole in the trans pan and he had drained all of his fluid. No wonder it wouldn't drive. Anyways, I digress. I welded the pan, filled it up, diagnosed and fixed most of the other issues and drove it down the street. It drives just fine, shifts smooth. I park it that night and in the morning there is a pool of trans fluid underneath. It looks like it's coming from where the transmission meets the center diff. Has anyone else had this problem and could give me some advice on how to remove the center diff without dropping the whole transmission?
I have already dropped the back end of the exhaust, taken off the heat shield, and disconnected the drive shaft.

P.s. To clarify, it is definitely transmission fluid that is leaking, and not gear oil. It's red Valvoline MaxLife.
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I have never seen that happen on a Passat before. I expect you can remove the tail of the trans with the trans in the car, but it's not going to be easy. There are about a dozen bolts holding the tail in place. You would need to lower the back of the subframe to have enough room to reach all of the bolts. I've never taken one off on a Tip trans, just the 6sp, so I don't know what to expect when you pull it apart.
Here are the pictures of the trans out of the car. You can see the long bolts holding the back 2 sections on the main body.
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You will need to access Etka (in the Info Forum) for parts.
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Discussion Starter · #3 · (Edited)
It seems to me that it's coming from in between what is labeled as #22, the intermediate flange, and the main transmission housing, but I can't quite tell for sure. I guess my next question would be does that #22 piece share fluid with the transmission or the differential? And what other potential places could transmission fluid be leaking on to my cats in that area?I would assume the #18 piece is filled with gear oil, so I'm also assuming I'll have to drain the center diff because it will open up anyways when I pull those long bolts off? Or do you think there's a way to keep it together at seal #15? I feel like that might be a stupid question, but I'm asking anyways. I'm assuming #22 and #18 are basically going to come apart when I pull all those long bolts, #17, off. Also, do you know if there is another seal in there, maybe similar to seal #1 on the front but on the back, that could be leaking, potentially not on that diagram you posted? I'm guessing and I guess hoping that it is that seal #24 because that seems to me the only place transmission fluid could be coming from in that area, unless somehow it is making it's way into the diff, maybe through that seal I mentioned, and the tailshaft flange is leaking trans fluid, making it look like it's the transmission. I'm just trying to brainstorm with all these educated minds before I pull it all apart and get myself in too deep and end up costing myself more money because I pulled too much apart or something. I don't have a ton of money budgeted to do this, so I'm trying to keep is as cheap as possible. I guess on that note, is that #24 seal a gasket that could potentially be replaced with RTV? I know you might not have all these answers PZ, but I'm hoping someone will.
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Here's some more pictures just to have a look at what's going on. After looking further, it really looks like it's coming from that tail shaft flange, but it's red. That's why I'm asking if the diff fluid and atf could have possibly been mixed somehow? Has anyone heard of that happening?
I was thinking about just replacing the rear pinion seal and the rear case cover gasket and the output shaft seal. I'm really not sure though, and I know this is a long post, sorry about that.
I'm guessing regardless of what it actually is, my next step is going to have to be to remove that tail shaft center bolt? So definitely draining the diff?
Maybe I should just pull it apart and see what I'm dealing with, see if there's red in the diff.
 

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#22 would probably have trans fluid in it. It may stay in place when the long bolts are removed as there are smaller bolts holding just that part on the passenger side to the main case. I expect the trans fluid and gear oil will leak out.

There are many seals not listed on that diagram, that's why you have to reference ETKA:

The rear seal on the center diff should only be leaking gear oil. It is possible the gear oil was replaced and they used a red colored gear oil or even that the center diff was mistakenly filled with trans fluid. I doubt it, but stranger things have happened. I expect the low fluid caused an internal seal to run dry and burn. On the 4Mo trans that I have seen run dry, they usually damage the front pump bushing, which requires a replacement pump.
 

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Discussion Starter · #5 ·
Okay, update. I drained the diff and pulled the tailshaft stub. The diff had no red in it, just what seemed to be very dark gear oil, and only about a pint of it. So now it seems that I have both a diff leak and a trans leak somewhere. I'm going to replace that tail shaft seal in the end cap of the diff housing today, clean everything, and put it back together and fill it up and see where it leaks from. That seems like by best option right now I think.
 
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