Crusader 454 rattling noise in gear

[SeaMcDog]

Trying to figure out where the rattling noise comes from when I put to Crusader 454 in gear forward or reverse, rattles like a nut is flopping around. Nothing in neutral I've searched a couple of links for suggestions. I disconnected the coupler and she still makes the noise when put in gear. I've checked the spark plugs they all look good and normal. I've tried pulling spark plug wires seems like they're all firing. The oil is clean. One thing I found was what appears to be exhaust floating on the coolant in the heat exchange. Could this mean a leak somewhere and causing the knocking. Trying to avoid pulling the gear and checking the damper plate. Any input or suggestions would be appreciated.

 

[alldodge]

Don't know for sure but have you looked in the exhaust to see if the are water shutters? If so they were made of metal and had rubber coating around the edge.

what appears to be exhaust floating

In most cases this is just sediment, but would have to see what your seeing. Has the coolant ever been changed?

 

[kenny nunez]

If it is not the water shutters then it is probably the springs in the drive coupler, Over a period of time they compress from the drive load and loosen up.

 

[SeaMcDog]

Thanks for the imput... I have fresh coolant cause I replaced exaust elbows. hanen't really put any time on engine since then. probally is old sediment. I'm still thinking a spring in damper plate. other links say make sure all plugs are firing. anyone know of a better way of checking if plugs are firing

 

[alldodge]

The good thing about some transmissions, is they let you know if the motor is not firing on all cylinders the same. The velvet drive trans will rattle in neutral if this is happening, but yours is doing it only in gear so this may be something else. To check your plugs, just pull the plugs one at a time to see if there is a change.

Your prop shaft may not be aligned to within .003 and the bolts may be loose. Which transmission do you have and is it direct or V drive?

 

[kenny nunez]

If you do check the shaft alinment be sure to do it with the boat in the water if it is on a trailer.