Engine coupler saga....

[lrdchaos]

So the end of July I hit something running across the lake, broke the tip of the scag and scratched the lower unit. 2 weeks later the Engine coupler went out. Took the boat into the shop around the 12-13th of August. I called today and he said that he had to order more parts. I guess when he took the engine out and replaced the coupler everything looked good. When he put the motor back in the boat, the outdrive and engine would not line up. He ordered rear motor mounts, but he's not sure that will fix the problem. This is a mercruiser\tahoe certified shop. Any ideas what could have happened?

 

[alldodge]

He ordered rear motor mounts

REAR motor mounts :facepalm: the rear motor mount is the rear transom plate and the rear of the engine sits on it.
http://www.mercruiserparts.com/Show...0&bnbr=50&bdesc=Transom+Plate+and+Shift+Cable

If the guy has difficulty aligning the engine I would do my best to take it some where else if he doesn't come up with a better response then rear motor mounts.

 

[Bt Doctur]

engine couplers go bad from mis-alignment caused by a collapsed rear mount. Any time you lose a coupler you ALWAYS REPLACE the rear mounts.

 

[alldodge]

engine couplers go bad from mis-alignment caused by a collapsed rear mount. Any time you lose a coupler you ALWAYS REPLACE the rear mounts.

Again learn something new today, never done that, thanks BT Doc. What parts are replaced?

 

[Bt Doctur]

Let us know if he charges you again to pull the motor.
these, press/burn the old ones out , press the new ones in.

 

[alldodge]

Still don't see any reason to replace the rear mounts unless they are falling apart. The engine sits on the fiber washer direct against the transom plate mounting. The rubber bushings are used to resist flex. The spring washer does the rest. So even if the mount was trashed, the engine should still be able to be aligned just from sitting on the fiber washer. Replacing the mounts will not magically cause the engine to come into alignment, the mounting points will not change from my view. What am I missing?

 

[Volphin]

I've never seen this done either? is it just preventative or related to bushing wear?

 

[NHGuy]

Hope your stringers or transom aren't sagged.
It's also possible the mounts are in the wrong place from the original manufacture. If the original mounts aren't mush or out of shape your mechanic should measure their positions to be sure they are placed properly. Get the shop to save the old mounts, it would be good to see how bad they actually are.
Does this boat stay in the water?

 

[Bt Doctur]

the rear housing "C" DOES NOT SIT on "D" nor the fibre washer. Without the correct height at the rear, the front mounts cannot correct the situation.
the rear mount is pressed in the housing and sits on the double wound spring. when torqued down ,unless the fibre washer was glued in place to hold it, it should be able to spin.. Not being able to spin it ,could mean the insert in the rubber has broken away and the rear of the engine has "squatted down" on the fibre washer.
Cheap insurance at $64.00 when replacing a coupler

 

[Fun Times]

the rear mount is pressed in the housing and sits on the double wound spring.

This is just in general and not at anyone in this conversation, Being an 2006 engine, the double wound lock washers shouldn't of needed to be utilize.

In some cases a shim would be needed for new complete repowers with/or a new design flywheel housing is installed on old engines needs the stainless steel washer (shim) that goes where the double wound lock washer would go to lift the rear of the engine but the front of the engine would need to go down a bit further than the old mounts would allow.....If that is the case for anyone reading this someday, then the quotes below are some ideas to consider.

I have done many motor mount changes, yes you are right old motor mount system is gone.... This is what I have done, little more work but it works...
When I have the motor out I cut 3/8 in. out where front engine mounts go/rest. I then reseal with fiber glass. I then reinstall engine bolt mounts down. You now will have more than enough room to move engine, up or down...

One more thing. If you don't want to do that, you can do this....Take mounts off and get a machine shop to remove some off the bottom. This will work just as great too!!!!

MCM Rear Engine Mount Design Change