I have a 1980 Honda no-ped express with about 2300 miles on it. I am uncertain when the transmission oil was last changed. I would love to give it one, but I am very nervous. I am worried that things will not work right after I change it or that something might break. Give me the reassurance that this is a good thing to do. Part of me wants to do it, the other half thinks "if it ain't broke, don't fix it". Please set me straight.