1984 Chrysler 45hp thumping/clunking noise

[CApTaInGoOfy]

Noticed a thumping/clunking noise last time I was out. It happens a couple seconds after I put it in gear. Just a single thump/clunk. When I first heard it I thought I might of hit something. But it seems to consistently happen after I put it in gear. Any help would be awesome.

 

[jerryjerry05]

No Title

Sounds like the clutch dog is worn? Possibly the forward gear mating surface that hits the dog is worn.
Possible the linkage isn't allowing it to fully engage? Unhook and shift by hand and see if it still does it??

​Pic 1 the edges are worn and that allows the gear to slid over and thump.
​Pic 2 It's a good dog, the edges are sharp and even.
​You dog doesn't look like these.

​The edges can be squared off with a dremel or a machine shop.

Slow shifting or hesitating when shifting or lots of use can contribute to the edges worn off.

 

[CApTaInGoOfy]

Sounds like the clutch dog is worn? Possibly the forward gear mating surface that hits the dog is worn.
Possible the linkage isn't allowing it to fully engage? Unhook and shift by hand and see if it still does it??

​Pic 1 the edges are worn and that allows the gear to slid over and thump.
​Pic 2 It's a good dog, the edges are sharp and even.
​You dog doesn't look like these.

​The edges can be squared off with a dremel or a machine shop.

Slow shifting or hesitating when shifting or lots of use can contribute to the edges worn off.

Where is this clutch dog? Is it a difficult fix? I am a little wet behind the ears when it comes to boat repair. But I can turn a wrench enough to restore/rebuild cars. Just did the impeller for the motor in August and then noticed this thumping when I was on the water on Wednesday. Thanks for the information and the pictures by the way.

 

[jerryjerry05]

Find a parts manual.
boatdotnet has good diagrams.
Force/ Chrysler is listed under Mercury
Look at the lower unit.
On the prop shaft between the gears is the dog.
​It takes no special skills to change it.
​Maybe a puller with longgggggg bolts to pull the carrier.

​The dog can be changed without any shimming or special tools.

​If it's not too bad and IS the dog that's bad it can be flipped around and the bad part will be used while in reverse.

​If the gears need replacing you'll need shimming tools.