The story goes like this. I parked my '88 F250 (5.8, 4X4, C6) last Tuesday morning when I got from work at 6am. Thursday morning I left for a 5 day vacation in the wives car. When we left there was nothing under the truck other than its usual quarter size rear main seal drip.

When we pulled up to the house this afternoon I immediately noticed a puddle under the truck. After getting unpacked I went down to investigate. The puddle is tranny fluid and it looks like about 1/4 to 1/2 a quart. It came down on the passenger side of the tranny.

This has happened twice before. Once It thought it was due to a loose pan bolt and the other time I thought it was overfilled. After the last time I made sure it had the right amount of fluid in it and it was fine for about a month until now. Every time this happens it is when the truck is parked for at least a day or two. I have checked the pan bolts as well as the vent and it is clear. The cooler line connections are clean also. The fluid does not seam to be coming from high on the tranny.

The only other thing about the tranny is it sometimes has to be completely stopped in order to down shift to first. In other words if you roll through a stop sign it won't down shift unless you gas it hard.

Is it possible it coming out of the dip stick? Why only when its cold and parked? I plan on yanking the engine and tranny over the winter to rebuild both but was just curious about this mysterious fluid puke.

 

The dipstick "O" ring could be the culprit.
When a vehicle is parked for a few days the convertor can drain back into the pan and raise the fluid level.

Before starting the vehicle pull the dipstick and notice where the fluid level is.

Start it, let the transmission engage etc.
Shut the vehicle off and recheck the level.
It will probably be quite a bit lower once the convertor has been filled.

 

Sounds logical. I'll give it a look. Thanks.