I left the transmission in when I removed the engine. Maybe this wasn't an ideal decision... Removing it separately was a bit of a pain. I supported the transmission with some pipe strapping when the engine was removed. The bolts for the driveshaft were very difficult to work with due to limited space. A lift would be nice for this work.
Once removed, the transmission was filthy. 4 hours of scrubbing later and it looks presentable. The EPA would not be happy with this effort. I used a combination of Zap degreaser, brake clean, foaming engine cleaner, boxes of scotchbrite pads, and brass brushes.
The clutch plates look good and I did get an alignment tool. I will evaluate the clutch plate condition and replace if needed (age unknown). The flywheel ring gear has a few nicks and may be replaced. The rear main seal leaked a lot of oil into the bell housing, all clean now.
I will change the fluid and look at the condition. I do not plan on opening up the transmission other than replacing any gaskets on any covers.
A very dirty transmission.
An hour into the cleaning effort, with hours to go...
All cleaned, well worth the effort.
Pretty well cleaned, a few areas that could be touched up but overall good.