Transmission leaks when hot

[Miah]

I just searched the forums and wasn't able to find anyone else with this issue...
2001 xj, 3"lift, 1" transfer drop, transmission cooler.

When my transmission gets hot, off road, towing, ect it starts leaking and only while the engine is running... when it cools down it stops, I add fluid and doesn't leak a drop. this has been going on for a few years now, I carry enough fluid to replace all of it. It stranded me with my four-wheeler in tow in the Ted Williams Tunnel in Boston (very bad).

Any Ideas? is there a vent that if the fluid expands it can leak out of? Its not coming out of the fill tube and I can't really pin down where its coming from.

Thanks for the help,

Jeremiah

 

[xcm]

in between the motor and trans (like where a rear main seal would leak?)? my old aw4 leaked there on long trips... i hope my new trans does not.

 

[Shorty]

there's a vent tube on the AW4 on the passenger side just behind the bellhousing

 

[old_man]

Slipping under load can overheat a tranny and boil out fluid through the vent and/or fill tube. Make sure you are not overfilling.

Verify the TC is locking up once you get up to speed. That drops the temps a ton.

 

[91to99]

Same issue with mine... what is best way to check if locking up? Both times this has happened to me I was in 3 and going up a long and steep canyon climb.

 

[Miah]

Thanks for the input, it must be over heating and boil out the vent.

My Tc does lock in 3rd and 4th, you can see the tach drop when it does.

Its never done it at higher speeds, just when I'm going pretty slow and it gets hot (traffic or wheeling and only in the summer). for example yesterday I just had ten yards of fill delivered so of course I had to drive up onto and then over it... while screwing around I notice that it was leaking, steady drip. Turned it off, let it sit, and then when I restarted it wasn't leaking any more, added a little fluid and was back in business.

 

[old_man]

Did you check the level before you added fluid?

 

[Miah]

Yeah it was down some, it took a pint or so... I'm pretty anal about checking regularly even though the level doesn't change unless it over heats. You can smell when it over heats because it drips on the exhaust.

 

[Bwillie]

I doubt that this is your problem but I've seen the welds on a couple of Chevy torque converters develop cracks and leak in a similar manner as you are describing. Both trucks were used for towing and saw lots of it. In both instances we found the issue after pulling the tranny and carefully inspecting the torque converters.