starboard Engine/transmission rattling noise in forward idle

Mark007

New Member
Aug 3, 2020
11
Pictou, Nova Scotia, CANADA
Boat Info
2005 Sea Ray 320
Engines
Twin 350 Mercruiser (5.7L) MAG MPI V drive engines
Please listen to my video and note the port side engine is quiet in forward gear/idle speed. Starboard engine is noisy in forward gear at idle. This noise goes away when increase throttle or in reverse. Do you think this is the transmission? Do you think this is a propeller shaft/engine coupler/transmission alignment issue? V drives present and 350 merc MAG MPI, new remanufactured engines just installed. Thanks

You tube link:
 
Usually comes from idle being a little low. Sometimes it as little 20-50 rpm. Common issue, not necessarily any real problem
 
Normal. This topic is all over the forum and web.. bottom line not the trany. It's the dampner plate between the engine and trany. Springs get a little loose over time and if the motor has just a slight miss, it shakes the plate. Bump the rpm up about 100rpm and it will go away.
 
I’ve been down this road before....
What your hearing could be the damper plate but, is more likely gear teeth clash in the trans. It’s a known phenomenon and is harmless according to the tranny manufacture. It’s only on one side because of the extra internal gear to reverse the prop shaft rotation. There’s a option to swap to oil instead of auto trans fluid to lessen the noise.
 

Forum statistics

Threads
112,948
Messages
1,422,804
Members
60,930
Latest member
Ebrown69
Back
Top