replaced flywheel....vibrates and soudns awful

[temperedtim]

First off hello,

I am a new owner of a family hand me down 1993 Maxum bowrider with a 3.0L Mercruiser and Alpha one gen 2 Drive. The boat had been sitting for a few years and the flywheel rusted through and needed to be replaced. Soooo the engine was removed, flywheel replaced along with maintenance etc. While removing the Stern drive I noticed water in the U joint bellows and also in the gear oil. I hoped (like all rookies prob do) that when I replaced the gaskets when installing the stern drive after the engine repairs that, that would take care of my water leak. Now that the engine is in and fighting to get the drive shaft in with the engine coupler I have two problems. The first is that the boat started right up and ran great...after revving it to about 4000 RPM is started making a serious vibrating....something loose kinda noise. I always think the worst of things and I suspect an internal engine failure....but it idles quiet as a kitten, only when you give it gas does it come apart....when it does come apart you can still give it gas, but it just get worse. Its not a knocking or grinding....sounds like something is loose. I will say I did not use an alignment tool when installing the stern drive. When I took the engine out I removed it from the boat hull.....front engine mount intact and thought that it would save me the trouble of having to use the alignment tool....in which I don't have. My second problem is that water is still leaking into my gear oil....and it is seaping out the top of my alpha. no gear oil seaping....just H20....like its coming from the cooling chamber not from the gear oil.

So, anyone think I got a bad engine now or should I take it apart and use an alignment tool...like I said it was fine for about an hour then with some heavy engine revving it started coming apart (sound). Could a bad alignment cause this serious vibration....it really hard to tell where its coming from...engine or drive shaft.

Also whats up with the water seap......why is there no gasket there...the water just comes right up to the cap but no gasket? Seems odd to me.

Anyways any help would be great. Im mainly concerned with my engine. I dont mind taking everything apart again and spending more time on it as long as the engine is solid. Its has always ran like a champ, smooth as a whistle and did so before I took it out for repairs.

Thanks,
Tim

 

[fasassvalk]

Re: replaced flywheel....vibrates and soudns awful

Still sounds like a flywheel issue, Did the bolts get torqued and thread locked ?
Maybe by wild chance it lost a balancing weight off of flywheel, (4,000) rpm rev you said then it started !
If flywheel worked loose you would expect to hear a knock that resembles a rod knock ?
When gremlins start after service, go back to the last thing you done first and recheck !

 

[Chris1956]

Re: replaced flywheel....vibrates and soudns awful

Tim, You should repost this in the I/O section. I would replace the universal joints, as they were sitting in water for some years. Likely the Ujoint bearings are shot and that is causing your vibration.

There is a gear oil passage between the top and lower of the outdrive. It is sealed with a doughnut-shaped gasket. You might replace it. in addition the early Gen II had dipsticks on the upper gearcase. you might check the seal on that. later Gen IIs had gear oil resvoirs in the boat. I presume you do not have this feature?


Finally water in the ujoint bellows indicates you need new bellows.