I'm pretty sure that the detent valve is not functioning properly in my TH350. I had it rebuilt and there was only half of a detent cable there when I removed it. Past owners rigged alot. So I hooked a new one up to the carb. Unfortunately the cable got pulled too far out I guess and the tip of the shaft that the cable hooks to inside the transmission jammed inside the cable's insulation. I could never get it to shift right. No big surprise! So now I've replaced the cable again, hooked it up right and it still skips 2nd gear under hard acceleration. It also won't downshift unless speeds drop to almost nill. I have ruled out vacuum as a problem. So all that's left is the detent cable and internal stuff. I want to get the car fixed for as little $$$ as possible becasue I'm trying to sell it. I was thinking of removing the pan and valve body to see if the detent valve got damaged or dislodged. Having never actually removed a valve body I figured I would ask around first.

I'm pretty mechanically able and have lots of tools, just no special transmission tools. Is it an easy thing to do or not?