Should A Bravo 3 Clunk?

300sflyer

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I have a twin engine 98 Monterey, [new to me this past spring] with a pair of Bravo 3 outdrives. When shifting the starboard engine into forward or reverse, it shifts very smoothly with almost no noise at all. The port side however, has a loud clunk sound when it shifts into forward or reverse. It sounds much like an alpha drive going into gear. Other than the clunk, both drives operate as they should. Both drives are the original 98 drives.

Why is it one drive clunks, and the other does not? Does the port one have an issue that needs to be looked at? I should add the oil levels in both drives are normal.

Thanks for your replies!
 

Don S

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Re: Should A Bravo 3 Clunk?

Are the idle rpms the same on both engines?
 

300sflyer

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Re: Should A Bravo 3 Clunk?

Yes, they are the same at about 600. [TBI EFI]
 

TilliamWe

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Re: Should A Bravo 3 Clunk?

my 1997 clunked from day one, and continued clunking for 11 years and 800+ hours. But the fact that your other sounds different does make it seem that the port side could be mal-adjusted.
 

Don S

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Re: Should A Bravo 3 Clunk?

Could be nothing more than all the backlash and tolerances are on the high side.
 

300sflyer

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Re: Should A Bravo 3 Clunk?

Both drives have about 550 hours on them. I have no idea if the clunk in the port one developed over time, or whether it has been there since day one.

Once I pull the drives off for the winter, [to change the oil, check the alignment ect] is there a way to tell where the noise is coming from without pulling the drive apart? I have a hard copy of service manual 11.
 

300sflyer

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Re: Should A Bravo 3 Clunk?

Hey folks,

My drives are now off the boat and in a heated shop. What should my next move be? If the port side linkage is slightly out of adjustment, could this cause the clunk sound as TilliamWe suggests?

Thanks again for all your help!
 

beermak

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Sep 21, 2012
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Re: Should A Bravo 3 Clunk?

adjusting and rutine maintence will do, almost sure
 

skydiveD30571

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Re: Should A Bravo 3 Clunk?

Hey folks,

My drives are now off the boat and in a heated shop. What should my next move be? If the port side linkage is slightly out of adjustment, could this cause the clunk sound as TilliamWe suggests?

Thanks again for all your help!

Yes a misadjusted shift linkage can cause a cone clutch shift to clunk. It may or may not be your problem, but it is a possibility.
 

300sflyer

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Re: Should A Bravo 3 Clunk?

Despite the bitter cold here this morning, [-13C] I found my way into the boat through the shrink wrap door, and checked both the port and starboard linkages with the plastic linkage adjusting tool. Both were indeed out of adjustment by about the same amount, that being about 1/8-1/4 of an inch. It was too darn cold to play with it today, but I will fix them on a warmer day. Given that I have no issues with the starboard drive, I suspect the linkage is not the reason for the clunk in the port drive.

Not too sure where I should go from here, as I have no special Merc tools to take the drive apart, other than your standard wrenches and sockets.
 
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