New noise near transmission

[andre]

Hello I have mk11 1997 with m35bc and a noise from the transmission at idle. The transmission works good and the question is how to know if the damper plate has a problem and can we hear that. Thank you from Montreal sailor.

[John Langford]

Hi Andre
A noisy damper plate at idle seems to be a common complaint for M35BC owners. I was idling around 850rpm and when I would engage the forward gear the damper plate would make a lot of noise. As an interim solution I have increased the idle speed (using a laser rpm meter) slightly above the manufacturers parameters (850-1000rpm) so that the damper plate is much quieter when I go into forward. In my experience, the problem is less of an issue in reverse. I am now at 1050rpm. The issue here seems to be finding a balance between a rattling damper plate and an idle rate that could do damage to the clutch when shifting. I am experimenting at the moment. BTW, I have around 2200 hours on my engine.

Of course, there is a possibility that my damper plate is damaged and needs replacement. On my boat to get at it I probably would have to release the aft motor mounts and loosen the forward ones to lift the engine enough to pull the transmission and Bell housing over the top of the half coupling. Because I have a PSS shaft seal there doesn't seem to be enough room to push the shaft far enough aft to do the job without lifting the engine up. I also am not sure if the job can be done without detaching the heat exchanger and other wiring and hosing that lie across the aft end of the engine.

Other readers may have had experience with this problem and have views on idle speed adjustment and the process for getting at the damper plate if required.

[Ron Hill]

John : It is going to be tight, but you should be able to get at the transmission and remove it without screwing around with the engine mounts.

A thought

[andre]

Thank you I will check for rent a rpm check instrument and adjust a little bit my rpm before to do something.w

[John Langford]

Andre
If you don't have any success renting a digital tach meter, you can buy one from Amazon.ca for around $25.

[Roc]

Correct me if I'm wrong, but i think the new replacement damper plate that Westerbeke now offers is a different design which is much more quiet.