Engine alignment question

Dunromin

Seaman
Joined
Apr 29, 2011
Messages
58
I am nearly ready to re-install my 470 Mercruiser engine, but I have lost the correct height of the front engine mount so I can't just pop it back in. Can anyone advise the correct procedure at this stage, to get the engine back in, and aligned properly?
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,351
Re: Engine alignment question

install the engine, adjust mounts accordingly to get engine alignment.There is no set height.
 

solar7647

Lieutenant Junior Grade
Joined
Apr 23, 2009
Messages
1,218
Re: Engine alignment question

You will need an engine alignment tool. You simply install engine bolt it down, insert alignment tool through the gimbal bearing and adjust the bottom nut on the front mount to lift our drop the engine until the tool slides in with very little effort if the tool requires a lot of force to get in it's not aligned. It is easier said then done and better with two people so your not jumping in and out of the boat. The first time I aligned my 3.7 it took about two hours of adjusting the nut back and forth 1/8 turns at a time because even a 1/2 or 1/4 turn can be way too much. If you don't get it aligned it will destroy your spline and/or drive shaft.

A couple vids one of the guys on the forum did, gives a good idea of how to do it,

http://www.youtube.com/watch?v=MYwnK8mjHdw&feature=youtube_gdata_player

http://www.youtube.com/watch?v=fA5ExlPVz2w&feature=youtube_gdata_player
 

Dunromin

Seaman
Joined
Apr 29, 2011
Messages
58
Re: Engine alignment question

Thanks, this is what I'm looking for. I know this is the kind of thing only a rank amateur would ask,
but for future reference, is it normal to do this any time the engine is re-installed, or should I just have left the front mount adjustment alone, and engaged the engine to the splined shaft without re-aligning? (Although, it looks tricky to re-engage the spline that way.)
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,351
Re: Engine alignment question

What splined shaft, you havent put the outdrive back on yet because it needs to have the alignment checked/adjusted BEFORE you re-install the drive.
 

Dunromin

Seaman
Joined
Apr 29, 2011
Messages
58
Re: Engine alignment question

I did not remove the out drive when I removed the engine, I slid the engine off the shaft, leaving it in place.
 

dubs283

Vice Admiral
Joined
Jul 27, 2005
Messages
5,333
Re: Engine alignment question

I did not remove the out drive when I removed the engine, I slid the engine off the shaft, leaving it in place.

not the recommended procedure for removing the engine

so much hassle to mess with getting everything re-installed, why not pull the drive?? its designed to be removed for regular maintenance (part of which is checking engine alignment)

pull the drive and align the engine
 

cr2k

Captain
Joined
Mar 19, 2009
Messages
3,730
Re: Engine alignment question

Yep now you are gonna have to pull it anyway. It may be way harder now since the splines will have a load on them form poor alignment. You did use Spline grease on them right?
 
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