S&G Tool Aid Top Dead Center Indicators

S&G Tool Aid top dead center indicators whistle as the piston approaches Top Dead Center (TDC) on the compression stroke, and stops whistling when the piston reaches TDC. This eliminates the guesswork involved when diagnosing jumped timing belts and timing chains, as well as aids in valve adjustments and installation of distributors, timing belts and timing chains. The 2-in-1 fitting threads into all 14mm and 18mm spark plug ports, and the hose has a 27 in. overall length. Not for use on diesel engines.