More Bravo drive problems

[Russell]

Whilst berthing the boat on saturday the port engine started making a loud whining noise, and wouldn't select any gears. Upon closer investigation it seems that the input shaft from the leg is turning freely(ish) in the back of the engine.
Now it seems 2 me that there could b 4 causes of this :-

a) The splines have sheared, but I had the legs off in the winter and they looked good. Also I thought they would have gone when I was flat out.
b) The coupling has come loose from the flywheel
c) The coupling has failed. I have never seen one from a 7.4 but maybe thay have a rubber insert or something similar.
d) The input shaft has come out of the coupling. Can this really happen ?

Has anybody had any similar experiences ? I would like 2 know a bit more b4 I get it lifted out 2 pull the leg off. If is anything other then (d) then the engine will have 2 come out 2, which is really bad news on this boat. :-(

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[Guest]

If it was whining, I reckon the spline's gone! some of the drive plates have an aluminium inner, so the splines are relatively soft, missalignment would soon result in failure. Although you had the drive(s) off, and presumably the donkeys dick looked ok, the drive plate is very hard to evaluate without removal.

Was there any signs of metal particles on the otherwise OK shaft spline when you looked?

What motors have you got?

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[Russell]

They are 1992 Mercruiser 7.4's. They splines looked clean when they came out, but they were a bit dry. The alignment wasnt 2 bad, but then it wasnt perfect either. I'm now wondering if I've got 2 take them out I might as well put some diesels back in. It would be a shame 2 lose all that horsepower though.
I think i'd best go round 2 the Merc agents this afternoon and ask them what sort of couplings the engines have got.

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