Oil Stain on floor :(

[mexicanS13]

So today i decided to chill at home and just work on some stuff on the car that i've had put a side for a while like paint my rims and ect... back to the story, i got borded and wanted to go for a small drive so i hooped on and turned the key.. then it happed!!!! the motor and transmission together were shaking. after a few seconds the car went back to normal. i drove around the block and parked. Then i noticed some slight oil stains on the floor. i got down like inspector gadget and smelled that s*** lol, to me it smelled like transmission fluid. I got the jack and lifted that son of..... and the transmission was covered with oil but from where was it leaking??? I also noticed that sometimes when i down shift it wouldnt go in to the gear i wanted so i kinda had a feeling it needed oil but didnt pay much attenction due to i drop like 3 bottles of Royal Purple in it 2 months ago when i first got the car plus what it already had. So what should i inspect first? The bell housing is clean from oil it was mainly from where the drain plug is back thats covered.
Will appretiate any help i get
Thanks!!!

[westxbay_S14]

replace the drain bolt make sure you replace the washer on it to(i think it has one)

[srpowered240sx]

replace the drain bolt make sure you replace the washer on it to(i think it has one)

word, if its from the drain plug back, id put my money on that. also check where your shifter bolts onto the trans, the seal there could be leaking.

[mexicanS13]

replace the drain bolt make sure you replace the washer on it to(i think it has one)

replace the drain bolt make sure you replace the washer on it to(i think it has one)

word, if its from the drain plug back, id put my money on that. also check where your shifter bolts onto the trans, the seal there could be leaking.

Thanks!!! today before i i left to work i moved the car and i had marked on the floor where the pliug was and rear seal but there was no leaks this time, also the car didnt shake like it did yesterday. Im just going to replace both and i was wondering how do you know when the transmission is full??? im planning next month to drop in new fluids completely from radiator to the weldel diff, thanks again!!!

[srpowered240sx]

Im just going to replace both and i was wondering how do you know when the transmission is full??

fill it on a level surface, and use the fill hole as an indicator. when the fluid spills out as youre filling it, its full. should be about 3 qts.

[mexicanS13]

[/quote]fill it on a level surface, and use the fill hole as an indicator. when the fluid spills out as youre filling it, its full. should be about 3 qts.[/quote]

Thanks!!! I last thing, sorry.. i went to a couple of auto stores and they said that they dont sale the seal that goes in the shifter. Any idea where i can get one? I havent tried NAPA yet tho..

[srpowered240sx]

try nissan.

[mexicanS13]

try nissan.

Sorry for the late thanks. i got the flu and couldnt do anything, but thanks for your help man