mercruiser 170 3.7l alignment problem

[mauiguy]

I bought a 19 ft. wellcraft 190 with a mercruiser 170 3.7l engine that had been laid up for over 4 years. Once I got the engine running I pulled the sterndrive and serviced it. When I removed sd I checked alignment with tool and it seemed fine. After installing new gimbal bear and seal three weeks later, I checked alignment and couldn't get the tool into coupling. Checking with a 1" pipe I saw the front of the engine needed to go down. Adjusting it slowly down it went to the stops before I could insert the alignment tool. Then I turn the engine 180 degrees and the tool wouldn't go in at all. I checked the stern mounts and transom plate visually and they looked OK. Is this a sign of a bad coupler? Any advice on how to precede before pulling engine would be a grat help. Thanks

 

[achris]

Hi mauiguy, and :welcome: to iboats

If it was fine before the gimbal bearing was replace, it will be fine after. What I suspect you didn't do was align the new gimbal bearing to the housing and coupler. You are aware that the bearing moves around in the carrier? Get the engine mount position back to where it was... Put the alignment tool in, but don't engage the coupler. Now lift up and push down, and move the bar left and right. It will take quite a bit of force, but the bearing should move around... Now get it close to centre, push the alignment tool in as far as you can, then either with the heel of your hand, or a soft mallet, hit the side of the tool, up, down, left right until the tool starts to go in... Once the tool is all the way in, do the same again, left, right, up, down.... The bearing is now aligned.. NOW do the engine alignment...

Chris.........

 

[mauiguy]

I did align the gimbal bearing and when I dropped the front of the engine the alignment tool went all the way in, but upon 180 engine rotation, it was way off.

 

[achris]

That would indicate the coupler... But, how was it ok before the bearing change and not ok after it?

 

[mauiguy]

I thought the same thing. Maybe I imagined I checked it. The sd was a little difficult to remove. I think since the engine is all the way down before the tool goes all the way in and will not got in at all when rotated 180 I'll try aligning it in the 180 position and I should have to raise the engine to insert the tool. Does that sound right?

 

[achris]

Yep, correct....

 

[mauiguy]

Upon rechecking alignment, as I rotated the engine the coupler seemed fine, but the engine front is all the way to the stops and it still needs to go down a bit further. That leaves the rear motor mounts are being too low. Can the double wound lock washer and fiber washer be worn? I've ordered a replacement, but wonder if this sound logical?

 

[achris]

If the rear is low, suspect the rubber in the mounts, not the double wound washers. The fibre washer is only the to stop the mounts hitting metal on metal. They don't take any load.

Unfortunately replacing the rear mounts does involve lifting the engine.

Chris.....

 

[mauiguy]

Is there any instructions (print or video) on how to remove and replace the mounts? Does the engine have to come out or just raised? Thanks for all your help

 

[achris]

You need to get the engine up high enough to knock the old mounts out, and press the new ones in. I would suggest you lift the engine about a foot in the boat, spin it 90 degrees and lower it down to rest on the floor of the boat, then remove the flywheel housing and work on that (replacing the mounts) on a bench and at your leisure.

Chris..........