might be missing a tooth off one of them gears.. if it only does it in that gear.. etc..
if it was 4th. and had a chipepd tooth, adn the price was right.. I'd buy it.
I almost never use high gear.
3rd on the other hand is a nice mowing gear.. i wouldn't buy it if 3rd was out.. unless it was a steal.. since you have to do a full split to rebuild the trans.. or ( preferred maybee ) just repalce it with a salvage one... again.. if the price was right.. I could do it..