"Clunking" Noise

[JBearsX5]

Good Morning, I have a 1990 GT 230 W/ 260 OMC and the last 2 times out I have heard / felt a "clunking" noise when accelerating. Belts -good -light wear. oil -full-clean. New plugs, cap, rotor, wires. It does not happen all the time but when it does it can be felt and heard through out the boat. It only happens in forward and can happen at part to full throttle- anywhere in the middle. I've heard it maybe a misadjusted lower shift cable. If so, what would be the correct adjustment proceedure?!?
Thanks,
PapaBear

[Donzi Blackhawk]

Could be a simple shift adjustment, could be the clutch dog jumping on fwd gear. Without a doubt check your gear lube for the metalliac look. I would fix this problem before something bad happens to your gearcase.

[JBearsX5]

Thanks, Forgot to mention that fluid was "stinky" , a little cloudy, but not metalic!
The shift / cable does seem to be a little bit difficult to put into forward gear.
Any additional thoughts?
Thanks,

[Murphy]

The clunking noise you describe could be coming from your outdrive upper gear case. If you have shucked a tooth on this gear, the piece is bouncing around inside the upper gear case. When it gets between the teeth, it is forced out and the clunk is pretty distinctive. Remove the upper gear case cover and have a look. If it's a small piece you may not have done too much damage yet. If it goes on you could be risking serious damage to the drive. Of course... it could be something else altogether but this is a sound all Alpha owners dread.

Good Luck,

Murph

[MOP]

More than likely the clutch dog is going, four or five bangs and it gets rounded off. The problem is caused by bad adjustment or bad cable. You can change out the cable but I am sure there is more to this. You have a seal that has let go and the oil is contaminated. Best course of action, pressure check and tear it down change out what it needs. Very important make sure you get the 5 degree cut clutch dog and forward gear, the updated Red drive cable. Also take a look at the shift interupter pack, check the number to find out if you have the last and best pack. If you have all of the above parts the drive is near indestuctable. Whether its a Merc or OMC if you start to get a bindy shift it must be fixed immediatly or you will LUNCH the lower gear case.