You should be able to get a local shop to do the whole job for around $1200. You do nothing but take it down there and then pick it up.

 

Your C6 works well when cold and slips when warm.
It's worn out. Weak worn pump and worn clutches. Come
to mind. This is where the Lucas shines. So either we are
not getting the whole story or your C6 is just FUBARed.
Really I have never seen Lucas not at least help some
with this. So there must be some thing wrong or broke in
there that I can't put a finger on. A C6 is a simple thing.
Your down to replacing it Bud. Maybe a 5 speed? I will when
the one in my Bronk takes a crap. Finding an F150 on this
rock to part out for a 5 speed is very difficult. I have everyone
and there bro's looking. The damn things are still all running.
Anyway when ya get your new C6 please come back here and
let me know what was wrong with your old one. It would be great
to have that info in this thread and in my head. Really. I want
to know as this just don't add up to me.

 

I'm honestly not sure what's going on. When it came to me it was slipping from take off when in drive and was always slightly better when starting from 1 rather than drive. I have done a complete drain including converter changed the filter and refilled with type f because previous owner had atf +4 in it for some reason I put in 11.5 quarts or so of type f and a bottle of lucas stop slip that didn't work so I took some more fluid out and added another bottle of lucas. The entire time though the dipstick always shows over full even before flush and refill as well as there are no bubbles on the dipstick. And it's not always a straight slip sometimes it slips for a second and then chatters badly until I give it more gas and it finally gets going the longer I drive the worse it gets. Then when it's been a while even when I go to turn the transmission slips while turning too its very weird. Which is why I assumed replace. I have a little money coming next month and am trying to plan ahead because at most i can only have 1 day of down time with my truck. When I changed the filter there was some black grit on the bottom of the pan.

 

I wish I could figure out what's going on if I replace it then it's getting another c6 for simplicity purposes. If you have any other questions let me know I'll tell you as best as i can what's going on.

 

If I remember right in a truck it should take more like 13 quarts.
Do ya have the right dip stick? A quart low could cause this.
I have seen them slip with less than a pint low. How much stuff was
in the pan? How much metal and brass shavings? Lots I bet.
Heck take it to AAMCO. They will really fix it for ya. Not.

 

There was no metal at all in the pan or filter though it looks like the previous owner had recently done a filter change and the bottom of the pan was pretty thoroughly coated in the grit with a thin layer.

I think the dipstick is wrong because it's always been way above the normal rating. I believe when I did the flush between lucas and fluid I always had a total of 12.75 to 13 quarts because I had asked about capacity prior. I don't have problems in any other gear and the trans does great once it gets moving.