Quick question on transmission shifting for a friend


A friend of mine put in a rebuilt tranny it shifts into 2nd at about 20mph which seem ok and in3rd at about 50 and 4th at 65 70 it seem to shift to late i had him check the fluid it about a qt low would this have any thing to do with late shift or do you 5hink its in the tv cable it was lates so he couldnt get any tranny fluid just look for a little advise
You will probably do better (get answers) if you post this in the trans section.