1993 240sx - transmission leak

[mmm240]

it's a manual now, but used to be auto.

i have searched and came up with rear main seal, rubber seal boot under the shifter, or it's leaking from the sensors.

my mechanic tells me it may be leaking from the top (of the trans) where the two pieces are sealed together, i am hoping not cause then i may as well get it rebuilt while it is un installed, i have yet to hear about this sort of problem from this forum, so i don't beleive thats the problem. is this an unheard of problem?

i didn't do the auto to manual swap and the guy that did (who i bought the car from) couldn't tell me anything about the trans, "found it in some guys garage", he says.

[NISTECH]

Its not all that common to leak from the case halfs. I would be more suspicious of the shift boot if its comming from the top. There is also a vent up top that can pass fluid if the fluid is overfilled.

[mmm240]

good call on the vent, i didn't know it had one and the car was tilted a little forward when i last filled it about 600 miles ago

thanks