I have a 1993 370 Searay Express Cruiser with Hurph transmissions and dual 454 Mercruier engines Ther is a loud rattling noise when forward or reverse gear is engaged. Everything is fine until put in gear at idle speed (700 rpm) wih engine in gear and i raise idle to 1000 rpm noise totally disappears. I have been told that it is transmission while other say damper plate. One experienced mechanc even suggested a "bad flywheel". i certainly do not want ot replace eveythign from the flywheer back. Any suggestuoins on how to proceed.
New tranny is about $3,000 while a new damper plate is arouinf $225. was told that "Flywheel" is about $175 but did not verify price. Of course to replace anaything is labor intensive.
Thank you for your anticipated advice.
Jim
