Nissan Patrol 4x4 (Africa)

Is there any reason why those pumps mechanics use to remove oil can't be used on the 4.8 Auto's box?

It's a suction pump works on vacuum and some have compressors. Is there a space limitation as to why is can't be used?

Roy there is a filler cap on the gearbox as far as I know also you can buy a dipstick if you want to .
just note that you must only use the ones from the stealers graham did mine at 120000