Good Evening, I'm hoping to get some direction. I have an 03 Expedition XLT, 5.4. Transmission fluid is leaking out of the vent (info from tech) after a 40 minute drive to work which consists of the 20 min express way 20 min city driving. When I go home the reverse, I do not have spots under the truck - center front under engine. Transmission was just serviced including filter, due to finding the fluid spots under the truck and dip stick not registering. Tech said I was over a qt low. 91K miles - no towing. Tech dropped pan and no shavings/fragments to indicate internal issues. Fluid was a little dark - needed changing - but not burnt. No noticeable driving issues. Any suggestions / guidance would be most appreciated.


Thanks,


Rhonda

 

Sounds like he overfilled your trans, where is the fluid on the stick now after the change? Did he check fluid level when hot or cold.

 

The fluid coming out of the venting was the reason for it going into the shop the other week. Fluid is not overfilled. Currently checked, warm - after drive home - running on flat surface - fluid at the top of "cold" indicator on dip stick.

I read on one of the forums about a seal that may leak when hot but reseal as it cools down - wondering how applicable that was? Also, since there seems to be a greater issue after the city driving vs. highway driving I don't know if there is any cooling capabilities involved. I am not overly versed in transmissions. Just looking for other ideas of quirks that could be causing this.. Thanks again.

Rhonda

 

The seal in question is only present on 4WD equipped vehicles. The seal is between the tranny and the transfer case. When the seal leaks fluid passes from the tranny and into the transfer case. Then someone comes along sees the tranny fluid is low and tops it off. Now you end up with extra fluid between the 2 units which expands when hot and this expansion raises the fluid level above full, so out the vent it comes. Because of the lower air speeds and the stop and go type of driving, the tranny will get hotter when doing city driving verses highway driving. I don't know if this is what's happening with yours, but based on your description it's a possibility.

 

Tech thinks it may be plugged cooling lines to / from radiator. However, lines and radiator are corroded and would probably need replacing if removed to investigate. Would having that work done be worth it? Ball park est $800?

Thanks again.

 

Disconnect the return line (it's the rear line) at the transmission, hook up 5 feet of clear tubing and put the other end in a bucket, start the truck and check for good flow. The fluid should pump out like water coming out of a garden hose. Not sure how much flow you'll have with a restricted/clogged line, I've only seen good flow as described when flushing the trans.

 

If those line were clogged the tranny wouldn't shift and would over heat.