What does this bolt do ? Advertisements What does the bolt below the filler plug do please? Share this: RelatedNot American But More Herald – Gearbox and Clutch RemovalApril 25, 2013In "Clutch"Triumph Herald Clutch Release Arm IssueApril 26, 2013In "Clutch"Triumph Herald Alternator Conversion (originally published in 2008)December 18, 2008In "alternator" gearboxTriumph Herald