I've never had a drop of fluid leak from my transmission until yesterday. I towed a very heavy trailer (10k or so with tons of tongue weight) about 300 miles and I got back and noticed a decent amount of fluid leaking. The transmission temperature never went over 160 on the drive. I know these transmissions tend to puke oil sometimes, but doesn't that only happen when they overheat, or would a very heavy trailer have the same symptom?

It appears the leak is coming from somewhere near the back of the pan around the gasket. More specifically, it seems the one bolt pictured below is leaking. All bolts are tight and the pan gasket was replaced about 6k ago with the last fluid flush.

Any ideas?



Cleaned up, then driven again, the source seems more clear:

 

Did you have to back the trailer up?

 

Yes, a few times, but not for long. Just maneuvering in a tight, relatively flat driveway.

 

May be unrelated because of leak location but I just had a similar problem. When my trans got above 155 it would leak from the front pump seal. Any lower temps it didnt even leak a single drop! All I did was flush the fluid and then changed the trans filter! The filter looked good and clean that I removed. It has been well over a month and I have gotten the trans up to 170 and not even a drop! Makes no sense to me butt it seems to be fine.

 

Mine has gotten up to 180 with no leaking but worth a try. The gasket was a new reusable napa brand one so maybe that's the issue who knows.

Would it puke oil in reverse with a heavy load?

 

I did not pull at all when I had that problem. I normally have temps below 150. I was only having the higher temps when I would do a lot of hard accelerations in 100* weather after an hour plus trip. The times I did tow it was always cool out and temps never came above 155, towing a 2000 lb trailer with a 3000lb car on it.

 

Very easily...I always put my transfer case in 4L (with hubs unlocked) when I have to back up a heavy load.

 

I replaced the pan gasket and it's still leaking! No towing at all since this new gasket. I'm stumped, any ideas?? Here are some more pictures if it triggers a thought for anyone:

 

Did u change your filter while the pan was down?

 

You might look at the dipstick tube as it enters the transmission. My car had a o ring that was leaking there and made it look like a pan leak.

 

No because I changed it about 9,000 miles ago so it's still got quite a bit of life left in it.

 

I'll check that out later today or tomorrow. Good suggestion.

 

Second pic down in the first post at the end of the boss for that bolt that comes in from the rear, right above the pan bolt, there is half circle line. Is it a crack?

 

Wow, I have been chasing this exact problem for a few weeks now. Changed the pan gasket and still leaks. Any updates on a cause?

Thanks

 

If a 4x4 could it be the seal between the transfer case? Think you said rear of the trans.