I was out testing props when all of the sudden i felt like one prop was no longer there. I checked, it was still there. I wasn't pulling hard so I doubt i spun the hub on a prop and this had me looking back to the coupler between the flywheel and the outdrive. It doesn't look all that hot and it is covered in tiny metal shavings. Looking at this pic it looks like I spun the splines out of the coupler...probably trashed the yoke on the u-joint...hopefully the yoke is made of stronger steel than the coupler and the coupler is designed to sacrafice itself sort of in the way a shear pin does. Having said this, I hope replacing the coupler does not involve replacing the complete housing.

SO here is what i believe is allowing the engine to rev w/o spinning the drive shaft.

[ATTACH=CONFIG]559121[/ATTACH]

I believe that when it comes to replacement parts from the drive side, I may need a new yoke, depending on how chewed up it is.

[ATTACH=CONFIG]559122[/ATTACH]

What i'm not getting a good understanding of is wat on the flysheel side of things I will need to replace?

[ATTACH=CONFIG]559123[/ATTACH]

Would I have to replace the whole back of the housing (part #1) or can what looks to be an insert in the housing be replaced (the rubber looking thing). Here you can possibly see this better, the picture is taken from a different angle on the port side engine (current issue is starboard).

[ATTACH=CONFIG]559124[/ATTACH][ATTACH=CONFIG]559125[/ATTACH].

I had to chuckle when I was what looks to be a grease fitting, if the engine needs to be pulled to fix this, I wonder how often the coupler sees grease go into that fitting!?

Any insights on the flywheel side parts I may need, if i have the right drawing (HP450) it doesn't show details or they want the whole housing face replaced?

Thanks!

- scott -

I grease the coupler on mine every 20 hours. There are two fittings on the coupler.

If you are lucky it's just the coupler....around $400. However, the motor will need to come out to replace it. How's your motor alignment? Bad alignment is usually what takes out the coupler.

doesn't look like you have enough shaft engagement w/ the coupler.is this engine mounted to a stack bravo inner transom plate?

And sometimes soft transom.

Hows your transom????

[QUOTE=dcb;4479061]I grease the coupler on mine every 20 hours. There are two fittings on the coupler.

There is special grease just for the coupler. I had a long extension hose made and a dedicated grease gun just for this purpose. If you do this make sure you get a good quality (not Harbor Freight) grease coupler. Don't ask me how I know that

3 pointstar

response to questions above.

the boat is new to me, the engine alignment will be investigated during the repair of this, The possible cost in parts being $400, is this for a complete new housing? if so, it sounds like it is implied that a coupler cannot be installed in the existing housing. On the surface this seems a a bit odd, but that appears to be what the diagram shows (althougy it is not terribly clear, I wish the diagram had a perspective facing the coupler from the drives perspective).

Transome is the first thing that came to my mind as a possible cause, I expect to learn more about this when the engine is pulled.

I honestly do not know what kind of bravo inner transom plate is in play? but I would suspect it is the ones Active Thunder shipped with the boat back in 96'.

How the heck do you get the grease fitting on the coupler? I had a heck of a time just getting pictues of the coupler..and I didn't even see the second grease fitting (but I also was not looking for it). Would lack of grease potentially cause this failure, seems not since the yoke to the drive app is probably worn down and that would imply the coupler is not frozen, correct?

If the yoke/shaft does not appear to be far enough inthe coupler, does that look to be true for both couplers?

LOL, I just learned of harbor freight a few weeks ago, already everything I have picked up has failed or been a disapointment.

Is the proper grease a aluminum-complex grease or a lithium based grease?

Thank-you!

Mercury has a spline grease.

Coupler is as big around as your flywheel.

The yoke never seems to get hurt, the coupler is rubber/aluminum and goes first.

.