Trojan Boat Forum

Does anyone have a vibration that lasts briefly when shifting into reverse? Only lasts a few seconds then goes away. Is this normal? Have not determined if it is just one engine/prop or both.

If you have forward momentum, what your feeling is cavitation. IF you are sitting still, could be a few different things. (Alignment, tranny, shaft, wheel, bearing )

I'm following this closely. My starboard engine vibrates for a few seconds when I first go into reverse. My theory is that when you first hit reverse you are probably carrying forward momentum and it takes time to stop the boat and reverse direction. This is when the prop shaft is under the highest load and the vibration is magnified. It probably means that our cutlass bearing is starting to wear out. Or the strut support is loose. At least that's my theory, but im hoping someone has an exact fix. Low fluid in transmission maybe?

I never thought about the forward momentum. Also if the prop is slowly still turning forward and then you shift to reverse that would accentuate the problem. I will test again with sitting still with no prop turning and see if I notice the vibration. It only lasts a couple seconds and then it is all quiet. Maybe I am being too critical of a 40 year old boat. Can't check my cutlass bearing until October but I sure will.

You want to see vibration, try backing and pivoting with 2 diesels while chasing a fish.

El L Sea wrote: ↑Thu Aug 22, 2019 1:43 pm You want to see vibration, try backing and pivoting with 2 diesels while chasing a fish.

THIS !!

TAD... I have the same thing. Cavitation is probably the cause. When I am idling forward and shift both into reverse, or idling forward and shift one into reverse to make a turn in a tight quarters, I get a bit of vibration / rattling for a few seconds. If I reverse from a stopped position, or when I am drifting forward very slowly, it doesn't happen.

Don't think you need to worry about it.

Come to think of it, It never vibrates when I back out of the slip so I think all is normal. I am going to check the cutlass bearing when it comes out for the season just to see if there is any movement out of spec.