Grinding when put into D or R 1998 Infiniti i30

Today my car started making a grinding sound when I put the vehicle into drive or reverse and when I take off the sound disappears completely but if I'm going around 10 mph the sound will start back up again usually while turning I read something that said a transmission can make sounds like that if it's low on fluid I added about a quarter of a quart of transmission fluid the transmission fluid is a clear red but I have noticed that it is low but I don't know if it's because it's not hot enough to be high on the dipstick about (quarter inch) onto the dipstick