PIC need help new gear box leak at fitting how do u tighten it

[chubsgts]

i installed new gear box and installed the new o rings on all the parts that swap over.
ive tryed to tighten this fitting 5 times maybe im doing it wrong any one have any input on this.
there is large fitting wit hex head and a brass fitting with a o ring in the middel of the threads that go thru the center of the hex fitting i keep getting a leak and im loosing my mind i hope some one has a answer

 

[97reddodge]

i used rtv on mine didnt leak did you have trouble with the pirman arm mountin position?