Mercruiser Transmission Issue

epupa

Recruit
Joined
Jan 7, 2004
Messages
5
Had an overhead situation with a 2000 model gas Mercruiser Mag 350 inboard with a Borg Warner Tansmission. The engine alarm went off and the transmission appeared hot. Was almost back to the dock when the alarm sounded, cut the engine and docked on the port engine. Boat was running for over 7 hours off shore prior to the alarm. Water flow was good, oil pressure and temp on the engine was fine, but the stbd transmission was 20 degrees hotter than the port trans. Mercruiser told me today the alarm goes off at 230 degrees, but the transmission was at 155 with a heat gun reading on the casing after in had been off only 5 minutes. Transmission fluid (Dexron III) was clear and did not smell. Will have the strainer checked and replaced and will have the fluid changed. Mercruiser said if the clutches were slipping the fluid would be dark and have a burnt odor, but did not see either. Suggestions would be most helpful. Thanks in advance for any help.
 

Mod2

Senior Chief Petty Officer
Joined
Jun 19, 2003
Messages
713
Re: Mercruiser Transmission Issue

I'm going to move your post to the I/O repair forum aftergolf.
 

snapperbait

Vice Admiral
Joined
Aug 20, 2002
Messages
5,754
Re: Mercruiser Transmission Issue

155 with a heat gun on the casting don't mean diddley.. The fluid temp is the critical issue here... Anytime that fluid goes over 190 degrees, the fluid needs to be changed.. (think trans alarm goes off at 180?)<br /><br />Do the obvious.. Check the fluid level with the trans warm (engine not running).. Drain and flush, replace the fluid.. Check the linkage to make sure the shift lever on the transmission hits it's detent..<br /><br />If that does'nt get it done, have the trans's pressure checked and go from there..
 

epupa

Recruit
Joined
Jan 7, 2004
Messages
5
Re: Mercruiser Transmission Issue

Had the trans fluid and screen replaced. No issues with fluid and no particles in the screen. Fished on Monday for 7 hours and in the exact same spot on the way back to the marina, the engine alarm went off. This time the temp guage on the engine was over 200 degrees and the alarm sounded. Shut the engine down and cruised back to my marina on the port engine. It appears that something is floating in the cooling system and moves around after going slow and then back on plane. Will look at all hoses and try and see if one is blocked. Also will look at the intake for the inboard engine to make sure there is no barnicle build up. I am thinking it could be a broken lose zinc or an impeller blade broken off. Do you have any other thoughts?
 
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