Go the trans fluid changed last night. It was low, but there was no noticeable leakage from anywhere. New fluid went in fine and it seems easier to shift, seems to engage more directly or something. Glad I did it. The old fluid was thin and pretty well black in color. The magnet on the plug had some paste covering it along with a bit of metal shavings, but not bad. The hardest part of the job was waiting while the honey-thick new fluid filled the transmission. I used a length of tubing and a funnel and filled it from the engine bay. Poor enough to fill the funnel, wait, repeat.
Hope to get the differential fluid changed tonight.
Next step is to chase down the oil leak that I have from somewhere about the oil pan (and maybe the oil pan as well). I will need a bunch of cleaner as the entire passenger side of the engine is covered in oil. leave a small stain overnight, but does not leak enough that I have needed to add oil.
After that I need to track down the problems I am having with the turn signals - they only work if I hold the lever down to the spot before it clicks to engage. If it goes all the way to the click, they don't work. And if the left signal is used, the brake light shorts out until the truck is turned off and restarted.