unpleasant noise

[yankeedoodoo]

Transmission noise: noticeable under acceleration a clicking/rattling sound from the gearshift area or slightly forward (?). Not a sound I like. It does not seem to be directly RPM related; but then I haven't tried a max performance run "to see what will break". I have the Caterham 6 speed trans. Any thoughts/ideas/experience on what this might be would be very much appreciated. Possible fixes are also sought. Thanks to all who offer responses. Saw a local exhibition of "classic Jaguars" this morning---nice cars (120's, 140's, 150's, E-types, etc.) but these guys seem more into polishing than driving.