How much gear oil do I need?

I wanna change the gear oil in my 88 b2200 5 speed transmission. I wanna avoid the 2nd trip to the auto parts store. Anybody know how much it takes?

when i changed out my oil, i bought three quarts, which was enough for the manual tranny and the diff (my as well put new oil in both), and i still had a some left over. When you're filling them, check the owners manual for a capacity for each thing (should be at the back of the book). if you don't have an owners manual, post here about that and i'll check mine tomorrow.
Bye the way, if you've got the money to burn, opt for full synthetic oil, even a cheaper brand.
I live in canada, and when the truck gets cold from sitting overnight, the tranny is really reluctant to shift into 2nd. But using full synthetic solves this. Full synthetic will also last longer, and won't get as thin in really warm operation.

if i remember right, you only need to fill to the level of the fill plug. both tranny and rear end, but dont knowhow much they take. sorry

That is correct fill the tranny till it spews out a bit put the plug in.