Transmission Oil Pan Leak

[disallow]

Hey everyone,

Haven't been posting as much in the last while, life caught up with me and I've been ridiculously busy...

Went camping for a week, and when I got back from towing the trailer (28ft travel trailer per my avatar) about 80 miles, noticed I could smell a little transmission fluid.

Got underneath and there is a leak from the transmission oil pan. See the attached pic. So I am not entirely sure if its the gasket that failed (most likely) or if I am getting some porosity due to heavy corrosion, and I need to replace the transmission oil pan.




Thoughts? I've found the Oil Pan for about $115 locally from Nissan. There are a few aftermarket ones out there for a similar price, that claim to reduce transmission temp and increase transmission fluid capacity.

The gasket is a no brainer, and available on rockauto for $15.

[docwatson]

The extra capacity might be nice since it seems like you tow (often?) with it. You're already going to have it off so it makes sense to me.

I hate rust after living the US Rust Belt for some years. Any time I see it, I have nightmares for weeks.

[smj999smj]

You could spray it down with brake cleaner to clean it up, drive it for a day or two and then re-check to see if you can pinpoint the leak. That said, it does look a little corroded. It would probably be a good time to replace it.

[disallow]

welp I got the pan off today. I found 2 spots where the paint on the inside is wearing off due to corrosion through the pan. So a replacement is on order.

Almost no debris on the magnets, so I guess that is good news for my old transmission.

See the pics below!

This is a pic that shows a rust spot starting in the middle of the pan. Looking underneath, it has a tonne of corrosion on it, so makes sense.



This one shows the rust spot through the inside of the oil pan from the side I found the original leak on.

[disallow]

Just a followup on this, I put my old pan back on and filled up with fluid. Well, the next morning, the pan was drip drip drip drip… I wasn't sure if maybe I overtorqued the bolts and it was leaking from the new gasket I put on or what.

So I pulled the pan off again, and did a little wire brushing around where I found the corrosion per the pics above. Well sure enough, pin holes through the pan. New pan is due today, got it from Endra's Infiniti in Ajax ON, for $85 +shipping/tax. Locally in Winnipeg it was $115+tax, and it would have taken a week to get it. I ordered from Endra's on Sunday and even with the holiday Monday, it should be here today.

I'm excited!

[smj999smj]

FYI, Nissan recommends replacing the pan bolts; the new bolts have sealant on the threads. IIRC, the torque spec is around 72 in/lb for the bolts? Never go more than 100 in/lb. The Nissan pan gasket is much better than what's available on the aftermarket.

[disallow]

Thanks SMJ.

As these aren't 'stretch' bolts (I assume, due to the low torque and being grade 7 fasteners) I won't be replacing them. However, I will apply some thread sealant, as it does look like the end of the bolt comes out of the transmission casing, and there could be an opportunity for the ends of the bolts to rust.

Also, with transmission fluid being as pervasive as it is, I would imagine the thread sealant is an extra protection against any seapage.

Will report back!
t

[disallow]

Well I've put about 4000km and 2 long trips with the trailer in tow, no leaks. Good to go!

[FLiPMaRC]