latest updates,
I put the shifting lever to the last position it could go to, it's supposed to be in (1), took off and the transmission shifted 1st & 2nd. I took the lever one step up and the transmission shifted to 3rd, took the lever one more step up and no change, the transmission remained in 3rd. I realized that there is something wrong in the shifting linkage, and the transmission itself.
I checked the TV cable and found out it's set to the maximum TV, so no drama regarding it, and furthermore, I reduced the load there and took a ride to check, still no overdrive. so I return the TV adjustment to the maximum again.
I disconnected the shifting lever and count how many clicks is there, and there was 6 clicks, meaning the transmission has 7 positions for the shifting lever which means P R N (D) D 2 1. when it's in "P", it takes 6 clicks to go to "1". so I tried to adjust the linkage, when I can reach "1" I can't reach "P" and vice versa. so I couldn't adjust it to have all the shifts reached.
then, I decided (desperately) to take a look on the governor since I don't have overdrive. and here were things went bad
I managed to remove the cover after many trials, but I couldn't remove the governor itself because I have a supporting rod going from the transmission to the transfer case and it's too close to the governor that when I try to pull the governor out, it'll hit the supporting rod and won't go anywhere. so I decided to return everything back and take it to a workshop since I don't have tools to remove that rod. I put the cover and put the steel luck over it, but it didn't luck perfectly

when I took off, the steel luck jumped aside and the cover reopened and I had the oil leaking outside the trany. I pulled over and put the cover again and tried to push it with a long steel rod because I can't hit it with a hammer in that so narrow space. I put the luck again, it seemed setting better. I add some oil and took off to a workshop that I used to deal with when I had my previous Chevrolet Caprice. I asked the mechanic (who I know) to take a test drive to diagnose the case. we took off, the cover set in place, the trany went 1st, 2nd and 3rd, then he pushed the pedal a little trying to reach a sufficient speed to hit 4th, that's when I heard a "click" sound and took a look from the side mirror to see a smoke behind us, and the cover on the street, and I went like,, Oops

we lost the cover... and he went like,, WHAT

.. did you open it??? and I said yes!!!
the good thing, we were one traffic light away from the workshop and we manged to arrive safe. my friend's (the mechanic) told me that since I have 1st, 2nd, and 3rd, that means I don't have to overhaul the trany. he'll check the solenoids and electric equipments inside the trany, and will reconnect the 3 wires cable on the driver's side, adjust the shifting lever, and I'll keep away from touching any automatic trany in the future

and hopefully I'll have overdrive if everything goes ok..
I'll let you know how it goes..
regards,
Mohsin.