i know that everyone has there thoughts on what to use, my 1974 calls for type f and my 1977 calls for 20wt, i used type f in the 1977 is this ok???? or does this hurt any thing. having some problems pu it away works fine. sat for 2 weeks went to test drive it would not go when i move the hydro lever made a ticking noise like a manual shift does when you put it in gear before you slow down, could not get the lift to work eithernused the draw bar raised it up at the same time i pulled the lever back, all of a sudden i know have foward and revers but no lift. iam thinking maybe i messed up not putting the 20wt in. any opinions or options.