I need help.
 

I am needing to change my transmission in my 1991 extended cab 4x4 3.0. I'm fairly new to maintaining my truck myself, and I think I have figured which is the fill plug and the drain plug but I haven't been able to find any confirming pictures. Here is the pic from my transmission:

The top plug looks like it has a sensor. In all the info I have read I've never read about a sensor. Am I correct in thinking that is the fill plug? And the bottom nut is the drain plug? Any advice would be extremely helpful.

From my shot time owning a A304h i think its filled through the dipstick with a long funnel.
drain plug is on the bottom.

Neither the fill nor drain plug has wires coming from it.

I can't tell you which sensor that is. I can't tell if I'm looking at the bottom or top (or side) of the transmission, but most of all I can't tell which transmission that is (automatic? Manual? Even then, you still need the model number: R150F, A340H, etc.

Someone else might be able to tell you all of that just from your picture, but on the assumption that you want help you might try to make it easier to get help. And, of course, look at the manual! http://personal.utulsa.edu/~nathan-buchanan/93fsm/

Last, you've got one hell of a leak somewhere; no automotive component should look that oily. The problem is that a leak anywhere on the engine ends up on the bottom of the transmission (gravity). I'd suggest you get some cheap engine degreaser (spray it on, hose it off) and get that puppy really clean. Then when you start it up, the first place oil appears is probably your leak.

Interesting. Thanks for info. My Haynes said there was an actual fill hole. Go figure. And the only plug on the bottom of my transmission is the one in the pic. There isn't a drain plug anywhere else on the transmission.

Thanks. Cleaning it up was going to be in the process. The pic is a side pic of the transmission.

Did Mr. Haynes happen to mention which transmission he was talking about? Cheez referred to the A340H.

The actual model number of the transmission is most easily learned from the sticker on the door pillar.

Which number would it be? Sorry bout it being sideways. The Haynes manual didn't give a specific number, but the again, I didn't look that hard.

R150F. Its on the bottom right above "Japan"

All that means is you have the 5 speed, not the Auto tranny.

Thanks Rattlewagon.

Page 44 http://personal.utulsa.edu/~nathan-b...nce/2maint.pdf

I don't know anything about manual transmissions, but I'm guessing the "sensor" is your backup light switch.

Scope103, this helped a lot! Thanks! Now that I've figured out which is which from all the help, I can't get the fill plug to budge. All I have is a 15/16 socket and a really big hammer (hammer is for hitting the ground when I'm frustrated). So it looks like I'm going to have to take it down to the local shop and have them bust it open. I tried myself, but I started to round off the plug. Thanks again everyone for their input.

Also Scope103, I hit the underside with five cans of degreaser and I'm still not done. It was pretty caked all from the oil pan to the rear of the transmission. The pics don't show anything particular except that it is really dirty with oil.