Thanks for the info ICANFIXALL.The truck was taken to that mechanic when my brother owned it.So i dont know if he took the gear cover off or not.But dont get me wrong the truck starts and runs smooth.When i drove it home from my brothers house i had it on a stretch of road and floored it,it kicked down and rpm's went up and didnt go any faster and the biggest black cloud of diesel smoke i ever seen came out the exhaust.So i stayed in it and it started to pick up speed and the smoke cleared up.Whats strange is it wont blow smoke like that anymore.Now the only thing i have done to it is turning the fuel up 2 flats and took the muffler off.Any idea why it blew that smoke out,now it wont?And being its turned up 2 flats and it didnt do anything,thats not right.