Alignment tool won't go in!

series60

Chief Petty Officer
Joined
Jan 4, 2010
Messages
420
1984 IMP with Mercruiser 305/Alpha 1
Well I have been fighting with this issue for days now, reading everything I can find with no results. The problem is the alignment tool will not go into splines more than 1/2 ". It appears to bottom out before completely entering the splines. I checked the alignment before ever moving the motor mounts initially and that is when I discovered the alignment tool would not go in all the way. At that point I started adjusting the forward motor mounts to see if I could get the tool all the way in. No luck, still bottoms out on one of the tool shoulders. I have read about the gimbal bearing being redesigned around 1984 and I am not sure which one is installed. Was there a different alignment tool design for the older bearings? Additionally I can see a rubber shoulder on the forward side of the bearing. This image refers to the rubber seal I am talking about. It looks like some kind of a sealing surface. I don't see this on any new bearing pictures. This is the type of installation I see when looking inside the housing. (Method A) The bearing runs smooth and I hate to replace a good bearing but if it is the old style it might not allow the alignment tool to slide all the way into the splines. Realizing this is a very old boat and the rear engine mounts have probably crushed down some, would this prevent the tool from going in all the way?

I would like any advise or instructions as to why the alignment tool doesn't go in the 2" approx. as it should.
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Alignment tool won't go in!

There were no new style bearings in the mid 80's. Forget about that Mercstuff information. You should NEVER change just the inside of those bearings as mercstuff suggests. It's the same bearing, just turned around.
If you can't get it aligned by raising and lowering the front of the engine, then if's very possible (especially after 16 years) that the rear mounts have failed and the back of the engine has dropped down. Or, even worse, someone had the engine out and didn't get all the hardware under the mounts quite right.
 

Rocky_Road

Lieutenant Commander
Joined
Oct 8, 2008
Messages
1,798
Re: Alignment tool won't go in!

No luck, still bottoms out on one of the tool shoulders.

This sentence makes me wonder about your alignment tool...since you state that it is going far enough for the "shoulder" to make contact. If that is true, then I don't see where you can do anything else to get the tool to go any further, short of eliminating whatever the tool shoulder is stopping at.

Where did you get your tool? There are dimensions posted somewhere on this site for having one machined...I would compare these dimensions to what you are trying to use.

Just a thought....

Happy boating!
 

series60

Chief Petty Officer
Joined
Jan 4, 2010
Messages
420
Re: Alignment tool won't go in!

This sentence makes me wonder about your alignment tool...since you state that it is going far enough for the "shoulder" to make contact. If that is true, then I don't see where you can do anything else to get the tool to go any further, short of eliminating whatever the tool shoulder is stopping at.

Where did you get your tool? There are dimensions posted somewhere on this site for having one machined...I would compare these dimensions to what you are trying to use.

Just a thought....

Happy boating!

I have checked all the measurements against the one listed on this forum and everything is as it should be. Is there a diagram somewhere showing the rear mounts with all the relevant parts included?
 

Rocky_Road

Lieutenant Commander
Joined
Oct 8, 2008
Messages
1,798
Re: Alignment tool won't go in!

I have checked all the measurements against the one listed on this forum and everything is as it should be. Is there a diagram somewhere showing the rear mounts with all the relevant parts included?

Don S. has posted the parts breakdown before...but I can guess that it will be a 'pain' to find by search!

Maybe Don will be willing to post it again, or I can see if I can scan something.
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,588
Re: Alignment tool won't go in!

Are you too high or too low?
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Alignment tool won't go in!

Mercrearmounts.png
 

series60

Chief Petty Officer
Joined
Jan 4, 2010
Messages
420
Re: Alignment tool won't go in!

Thank you all for your valuable info. It is great for this ole' shade-tree to have such gracious and knowledgeable folks willing to give freely of their valuable knowledge. Got to go see the ol Dr. today so will get back to the boat soon.
 

rad1026

Chief Petty Officer
Joined
May 1, 2006
Messages
443
Re: Alignment tool won't go in!

So why is no one suggesting re-setting the gimble bearing to match the coupler? Is that only done on a new gimble bearing, a one time deal? I'm getting back to my alignment this weekend and its confusing to me that he couldn't wack the end of the alignment tool to set the gimble bearing. Someone please explain.
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Alignment tool won't go in!

So why is no one suggesting re-setting the gimble bearing to match the coupler?

Quite honestly, I figured since he has been "Reading everything I can find" and about 50 to 75% of the posts mention it that he has already read it and done it. He also says the alignment bar ill go in 1/2" and no further. Kind of tells me the gimbal bearing must be set a little bit or it wouldn't go in that far.
"Wacking" the bar on the end is not really a good thing to do.
 

rad1026

Chief Petty Officer
Joined
May 1, 2006
Messages
443
Re: Alignment tool won't go in!

great pics on the restoration series. Let us know how it goes with the alignment.
 

Brew2

Chief Petty Officer
Joined
Jan 12, 2004
Messages
427
Re: Alignment tool won't go in!

Wow! That is one serious rebuild you are working on. Thanks for sharing the story and pictures.

I wasn't really looking forward to the few hours of maintenance I have to do on my boat....now it doesn't seem nearly as daunting!

Good luck!
 

rad1026

Chief Petty Officer
Joined
May 1, 2006
Messages
443
Re: Alignment tool won't go in!

Thanks for sticking with this one Don. Help me though because I'm still confused. I'm pretty dense sometimes. You're last statement, "Wacking the end of the alignment tool is not really a good idea". Are you saying that once a new bearing is set you shouldn't have to ever really set the bearing again? And that further alignment from then on, once the new bearing has been set, should only be done with the lowering or raising of the front engine mounts? And that if the alignment is so far off that proper alignment can't be made from year to year by adjusting the engine mounts then probably something has happened to the mounts and the bearing should not be readjusted to compensate for a possible engine mount problem? Am I on the right track?
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,588
Re: Alignment tool won't go in!

Setting the alignment of the bearing itself is only needed when you first put the bearing in. The reason is that you set the angle of the bearing due to the angle of the hull not being parallel to the engine. Once that is set, then the task is to adjust the engine alignment to the drive shaft which is where you are at right now.
 

series60

Chief Petty Officer
Joined
Jan 4, 2010
Messages
420
Re: Alignment tool won't go in!

So why is no one suggesting re-setting the gimble bearing to match the coupler? Is that only done on a new gimble bearing, a one time deal? I'm getting back to my alignment this weekend and its confusing to me that he couldn't wack the end of the alignment tool to set the gimble bearing. Someone please explain.

re-setting AKA hitting something just doesn't set very well with me. The problem is I have no concept of how much BFRM I need to use.
 

rad1026

Chief Petty Officer
Joined
May 1, 2006
Messages
443
Re: Alignment tool won't go in!

ahhhh, the light bulb is going off now. Thanks Bruce. I'm sure if I'd seen it done once I would get it. You would think there would be some you tube video showing the setting part, so us novices would get an idea of how much force it takes to set the bearing. I haven't seen anything. I've read everything from using a dead blow hammer to hitting it with the palm of your hand. I guess I'll just have to figure it out this weekend and report back.
 

bigskiohio

Master Chief Petty Officer
Joined
May 3, 2008
Messages
882
Re: Alignment tool won't go in!

i just used my hand and you can feel it , just start the bar the thump it on the four sides . if you cant start it your engine is not close enough, adjust or replace the mounts and washers if it wont align close enough. When you thump the bar you are kind of trying to make a circle an that squares it up . try it and you will understand then you can try the hard part of explaining it.
 

Friscoboater

Captain
Joined
Jul 3, 2009
Messages
3,095
Re: Alignment tool won't go in!

I had a similar problem and I had to drop the front of the engine four turns before it would go in.
 
Top