Black transmission pan-possible causes?

[jrisingmoon]

I pulled the transmission pan off my truck to replace the filter and the gasket and the inside of the pan was black and a bolt was rolling around in the bottom of it. I'm HOPING that the bolt was for the filter but I haven't checked yet. The fluid has smelt burnt since I bought the truck a few weeks ago and the previous owner has reported fluid leaks. It's an 89 F150 automatic 5.0. I don't know anything about transmissions except that burnt smelling fluid and leaks are a bad sign. I don't see any shavings so that's encouraging.

 

[bikepilot]

If the fluid wasn't changed in a while its normal for the botom of the pan to be black. No idea about the bolt.

 

[jrisingmoon]

I changed the fluid, filter, gaskets. The fluid, pan, filter were all black and sooty. I think the filter was clogged keeping the old fluid from being cleaned and maybe even keeping the fluid from getting from the pan to the transmission. I'll see what happens in the next few days.

The bolt was nothing major. There were about 20+ bolts around where the filter connects with the transmission. I found the only hole there and tightened about as much as the others. I guess it just got loose and fell.

The truck does run smoother now, I might add. That's encouraging.