Gimbal bearing or alignment first

[tailwind 67]

I have read numerous posts on alignment looking for an answer. I seem to have a common problem that my engine is down all the way on the front mounts but it seems like it needs to go a bit lower for alignment. I can fit the alignment bar in all the way but it is a shove rather then a gentle push. I have already tried banging the bar one way or the other once it was installed to see if it would be easier. I do have the original fibre washer and the double coil washers installed as well. I had to drop the front mounts about an inch on the engine re-installation to get to this point.
My question is that I need to change the gimbal bearing too. Should I put the new bearing in before I get the perfect alignment or should I try and get the alignment before I put in the new bearing? The old bearing is partially seized and has not been used for about 10 years. The boat is a 1990 Cadorette 260 with a 5.7 Mercruiser that I just finished a complete rebuild on. I have already done a start and it runs good in the driveway...it is just alignment and the bearing that is holding me up.
Thanks for any responses.

 

[wellcraft-classic210]

Re: Gimbal bearing or alignment first

If the Gimbal bearing is seized you may wannt to change that first. Its pretty hard to say if its on center or offset from wear and rust growth or other issues.

The Coupler you are aligning on the back of the crankshaft to is rubber and can get distorted -- especially if pushed to one side for an extended period as is often the case in poor alignment & storage. You may want to spin the crank in 4 positions & find the happy medium by splitting the difference. That may also be a new position that is not out of range for your mount adjusters.

---If the Coupler runout is excessive it could be a coupler problem.

--- If the runout is not excessive and thwe new bearing does not help perhaps something alse is wrong. Has anyone ever rebuilt the stringers and did they get thing back to spec?

 

[haulnazz15]

Re: Gimbal bearing or alignment first

Well, aligning the engine and then putting in a new gimbal bearing is kind of like wiping before you poop. Change the bearing/race, then retry the alignment procedure.

 

[Bondo]

Re: Gimbal bearing or alignment first

I have read numerous posts on alignment looking for an answer. I seem to have a common problem that my engine is down all the way on the front mounts but it seems like it needs to go a bit lower for alignment. I can fit the alignment bar in all the way but it is a shove rather then a gentle push. I have already tried banging the bar one way or the other once it was installed to see if it would be easier. I do have the original fibre washer and the double coil washers installed as well. I had to drop the front mounts about an inch on the engine re-installation to get to this point.
My question is that I need to change the gimbal bearing too. Should I put the new bearing in before I get the perfect alignment or should I try and get the alignment before I put in the new bearing? The old bearing is partially seized and has not been used for about 10 years. The boat is a 1990 Cadorette 260 with a 5.7 Mercruiser that I just finished a complete rebuild on. I have already done a start and it runs good in the driveway...it is just alignment and the bearing that is holding me up.
Thanks for any responses.

Ayuh,.... Ya gotta change the bearing 1st, Yes,... a Smooth bearin' oughta make things alot easier,...

Did ya inspect the rear motor mounts in the flywheel cover,..??

 

[Don S]

Re: Gimbal bearing or alignment first

Dead rear mounts or a rotten sagging transom can also cause you to not be able to adjust the front of the engine low enough. All it would have to do is sag 1/32" or less, and you couldn't adjust the front low enough.

 

[84EdH]

Re: Gimbal bearing or alignment first

Don, please explain. how could 1/32'' sag cause the front to be unable to adjust low enough? I dont understand. (unless the adjustment was all the way down when last aligned)

 

[Don S]

Re: Gimbal bearing or alignment first

A very small change in the back takes a lot more adjustment up front to make up for it. Since the gimbal bearing is gimbaled, then it can change and aim down. But if there is not enough room up front to go down enough, then it won't work.

 

[mr 88]

Re: Gimbal bearing or alignment first

If your motor was that far out of alignment to begin with,your coupler would be trashed out as well,so when you pulled it out the coupler was lined up. Engine,is it a rebuild,new block or has something been changed on the engine mounting brackets to change the height? Something isn't adding up unless the stringers rotted out in that area as suggested above.

 

[tailwind 67]

Re: Gimbal bearing or alignment first

Thanks for all the replies. We are going through a few days of rain up here so I am waiting to get back out in the yard and check things out. Lots of good points though. I will try spinning the coupler first to a few different positions. That is quick to do. Then I will change the bearing anyway and then check alignment again. As for rear mount position, it got me thinking. The boat has been on blocks in the driveway for two years now. The keel is sitting on three of them and then the hull is supported on either side to keep from swaying. I wonder if sitting on blocks could flex the hull enough to make the difference? 1/32 is a really small amount. If I am looking at the back mounts, is there a way to tell if they are good or not? The stringers where the front mounts sit all seem very solid.

 

[tailwind 67]

Re: Gimbal bearing or alignment first

I just rotated the engine and checked it with the alignment bar. The bar will not go in all the way when I rotate it around until I get it back to where I had it. I guess this means it is out of round. It goes in partially but not all the way. Should it be perfectly even all the way around, or is there tolerance for a somewhere in between with the engine adjustment...i.e it goes in all the way but is a bit too far down at one spot, or it goes in all the way but it is a bit too far up on the opposite.

 

[tailwind 67]

Re: Gimbal bearing or alignment first

The engine is the same engine completely rebuilt with the same motor mounts on the engine. It has been out of the boat for 2 years but the boat has been out of the water for 10. The stern drive came off easily but I have no idea how good the alignment was when I took it apart.

 

[wellcraft-classic210]

Re: Gimbal bearing or alignment first

If you can find a piece of 1 inch OD meta stock l ( I have a scrap of aluminum about 10 inches long ) You can place it in the hub and spin the engine to get a feel for how bad the runout actually is.

I was able to split the difference on mine. It was off less than 1/4 inch and its been running fine ever since (about 3 years ). I think it took a set from sitting for an extended period and being out of alignment.


I am not sure how bad the coupler runout has to be to decide to replace vs finding the average. Hoping one of the many experts here can offer some advise.

 

[Dixemon]

Re: Gimbal bearing or alignment first

I might be able to clarify a portion of the alignment procedure for you. If you are trying to adjust the gimbal bearing while the alignment tool is fully engaged in the coupler, It will not work. You must put the tool in the very forward portion of the coupler, not all the way in, and then tap or pull the handle around to center the bearing to the coupler. You may have to work it in small incriments, bumping it a little this way, then back the other way, ect.. until the tool slides in freely. In addition, its a balancing act with the motor mount position as well. I would put your mounts back to where they were originally located, and try again utilizing this method. It can be a very tedious process of finding that sweet spot. Hope this helps.