I think my tranny started leakin over turkey day. It sat for a week and now I think I need to add fluid and I know where to add it under the truck but I dont know how to measure if it needs fluid or not. It has been sitting for a month because someone stole my catalytic converter, and i only noticed because every couple days i go and let the truck run for e few minutes. Why would it start leaking all of a sudden?

 

Free FSM (Factory Service Manual) Will tell you how to check your fluid level.

You'll get a better answer regarding the leak issue if we knew where it was leaking from.

 

We have links to the FSMs available here stickied in the tech section.

 

I cant tell. it looks like the gaset and there is a small brass tube at the front of the tranny i found with some tranny fluid on it. I have no clue.

 

There's an oil fill plug on the side of tranny, trans case, and f/r differentials. They also have drain plugs underneath all these parts as well. IIRC all of them are 22mm hex or something like that. If you plan to drain one, always make sure the fill plug is not siezed on first! As for capacities and type of gear oil or change intervals of each I don't know off the top of my head (google them or fsm), but to check the level if ever curious:
Open fill plug and put finger in to check where top of oil is. Oil should be at the top for max fill. Good luck.