Leaking trans fluid

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Dec 4, 2019 | 01:36 PM

Sean4413

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Leaking trans fluid

Alright guys I have a 2014 M7 that I did a cam package on. While having it tuned, it started leaking fluid after a few pulls. Finished tuning it as it was very very minor drips and we thought maybe it was the rear main. After I got it back to my shop I took my borescope and checked the back of the motor. Completely dry. But the fluid is leaking from the bottom of the bellhousing. I’ve driven the car a few times now and the undercarriage is coated now. Never lost a drop of oil off the dipstick and by the smell, it seems like it’s trans fluid. Is there a seal in the torque tube behind the TOB I need to replace? Can someone point me in the right direction ?

Dec 4, 2019 | 02:12 PM

X25

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From: Sammamish, WA

Have you ever changed the transmission fluid? Like many others', my transmission also started leaking fluid after I changed it. I finally got it to the service, and they traced the leak back to the breather on the top of the transmission. It appears filling it all the way up until the fill plug adds too much fluid on these transmissions, and causes these issues, likely due to the additional volume by the cooler core and lines, etc.

Dec 4, 2019 | 02:45 PM

Sean4413

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Yeah now that you say that, I changed it before I had it put on the dyno. But how would the vent (at the back of the car) cause it to leak out of the bell housing at the front?

Dec 4, 2019 | 03:02 PM

X25

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From: Sammamish, WA

Especially when the gas tank is not full, the rear of the car is a bit taller than the front. In my case, I see deposits as front as the start of the transmission, but who knows, if it's transmission fluid, there's only one source : )

Dec 4, 2019 | 03:33 PM

Sean4413

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Is there a seal in the torque tube or something that could allow it out of the front of the tube behind the throw out bearing ?

Dec 6, 2019 | 05:45 PM

Avanti

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From: Bonneville Salt Flats

My new M7 came filled to the bottom of the fill-plug hole, that with the car perfectly level... no issues, no leaks in over two years like that. Just saying, I'm convinced that in and of itself is the cause.