When replacing the front main seal on your Prelude, be very careful to make sure the old seal has not worn a groove in the nose of the crankshaft. The later Acura Integra B-series engines are famous for this with the rear main seal, and if the groove is not covered with a metal sleeve before the new seal is installed, it will tear up the new seal and start a nasty leak. Ask me how I know—it happened to me on my ’98 Integra! I am not sure how prone the A-series Preludes are to this vis-à-vis the front main seal, but it’s definitely worth checking carefully and maybe even buying a front main seal that already comes with a sleeve. As for rear main seals, trust me, it is NO FUN taking a transmission off a second time to get at a new seal that has been ruined!
