Motor alignment incorrect because of incorrect assembly of motor mounts?

nickande

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I just had my '95 3.0 rebuilt and install last week. I blew the coupler at the end of our week long vacation. Suspect alignment issue. I'm wondering if I have put the bolts/washers back on correctly? I looked at the bolt and used the different shades on the bolt to figure out what I thought was correct. However, since I have blown the coupler, I suspect maybe that was the issue.

This is how I have put the bolt assembly together starting from the top of the bolt and working down:
aluminum washer (about 1/2" thick)
aluminum flat washer (about 1/8" thick)
fiber washer
double coiled lock washer
Engine bell housing
Gimbal/Transom mount
aluminum nut

Is this correct or did I inadvertently miss-align my motor by assembling incorrectly (and blow my coupler)? (I didn't change the front mount at all, so I didn't think I needed to to realign anything).

Looking from the rear (without using an alignment tool) it looks like the rear of the engine should be up a bit (or the front dropped).


Here's a picture from the top:Motor mount bolt.jpg

If the above is not correct, how should it have been assembled? Using my "keen eye), I'm thinking the lock washer maybe should have been put between the transom mount and the motor bell housing?

Is there an assembly picture from a manual someone could copy perhaps? Or just listing the order is fine as well.

If there is something that goes between the transom mount and the motor bell housing, is there any hints on how to keep the part(s) there when installing the engine?

I am currently trying to make (or buy a alignment tool) as well to verify the alignment.
 

Don S

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Re: Motor alignment incorrect because of incorrect assembly of motor mounts?

Your mounts should go together like this. And you really need to spend some time reading this thread on alignment. http://forums.iboats.com/showthread.php?p=2971085

attachment.php


Your alignment bar dimensions are like this.

attachment.php
 

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nickande

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Re: Motor alignment incorrect because of incorrect assembly of motor mounts?

Don, thx much for the info.

I printed the "how to out" from a previous thread that MarkSee replied to. (sorry about hijacking the end of that thread).

Two additional related questions:
1) On the dimensions (when creating the tool)... do you know what the tolerance for the diameters should be (+/- .01 or something)? Hoping the tolerance isn't too tight as to make it difficult to make.

2) If I was to try and see if my local Merc. dealer has one that I could rent/buy, do you know what the Merc part # would be? (I tried calling them but the parts dept. referred me to the service dept. and vice-versa)

Thanks again for the help!
 

Don S

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Re: Motor alignment incorrect because of incorrect assembly of motor mounts?

I would keep the dimensions shown to .005 undersized for the first from the left and third steps in diameter. You want them as close as possible. You can usually find new aftermarket bars on ebay for around $40 or so, no need to by OEM. Oem is over $150 and not worth it.
 

Bt Doctur

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Re: Motor alignment incorrect because of incorrect assembly of motor mounts?

usually coupler failure from misalignment is due to the rear mounts going bad,and/or rotted front engine bed stringers.
saying the rear is low could be an indicator that the rear bushings went bad and dropped the rear mounts.
 

Don S

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Re: Motor alignment incorrect because of incorrect assembly of motor mounts?

usually coupler failure from misalignment is due to the rear mounts going bad,and/or rotted front engine bed stringers.
saying the rear is low could be an indicator that the rear bushings went bad and dropped the rear mounts.

Did you look at his picture? All the mount hardware is on top of the flywheel cover housing. No wonder it's low.


attachment.php
 

Bt Doctur

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Re: Motor alignment incorrect because of incorrect assembly of motor mounts?

I'm thinking the lock washer maybe should have been put between the transom mount and the motor bell housing?


I did ,but dont see the doublewound.Got to assume its there between the housings.If it is between the fibre one and the steel one, then that is why the rear is down a bit.. the fibre washer usually spins unless the mounts have failed and allowed the housing to drop on them.
 

nickande

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Re: Motor alignment incorrect because of incorrect assembly of motor mounts?

Hey thanks for the additional comments.
As Don S. stated I had the hardware (the double wound lock washer and fiber washer) on top of the mount when they should have been in between the rear mounts and the inner transom mount, as depicted in the diagram Don provided earlier in the thread.

HOWEVER, attempting to align the motor with the "correct" configuration still failed. I was not able to drop the front end enough to get the alignment correct (the front motor mount was almost at the bottom before I attempted any alignment changes). The front stringer looks brand new and no sign of any sagging (interior is completely fiber glassed). After getting very frustrated I finally loosened the rear motor mount bolts and then tried lifting the rear of the motor up slighly. Doing that did the trick. Once I figured out the rear was still too low, I ended up putting the flat washer in between the motor mount and transom mount as well (with fiber and double wound lock washer). At that point I was able to get the motor aligned by raising the front a couple of turns from being bottomed out.

This of course concerns me since I figure you should never have to do this!! However, I now wonder if the motor have actually gone bad? Could that have occurred because of incorrect assembly on my part to begin with? That is, did the motor mounts likely move because I put the double wound lock washer on top for a week? I'm pretty sure that what took out my coupler to begin with... could it have caused a motor mount issue as well? Can you replace the motor mounts in the transom or bell housing? When I had the engine out, I remember the motor mount insert being lower than the rest of the mount (which should raise the motor if it was resting on something). When I had the fiber washer and lock washer in the transom mount I remember the lock washer being basically flush with the top of the fiber washer. Without the washers on the transom mount, I don't remember if the inner mount hardware was flush with the top of the transom mount or if it was below some what. I'm thinking it was somewhat below, which is why I think I put it together incorrectly in the first place (I assumed the motor mount "should" slide into the "peg hole" on the transom mount). I guess what I getting at is what "should" the motor mounts look like if I take the engine out again? Should the inner ring of the transom mount be flush with top of the transom, or should it be recessed somewhat? If recessed how much? How would I tell if either transom mount or engine bell housing mount is bad? Can either be replaced?

Additionally, (maybe I should start a new thread on this but it's related), since aligning the motor I have taken it out to the lake and did some testing. Ran great up until about 4500 RPM (just under WOT). At the higher RPM I hear a noise that sounds like a bearing that might be starting to go. Almost a high pitched grinding noise. I'm hoping it's my power steering or alternator... but concerned it coudl something more serious. I'm going to test things out more this weekend (at the house) and pull the alternator and power steering pump to see if that cleans up the noise.
 

nickande

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Re: Motor alignment incorrect because of incorrect assembly of motor mounts?

Ran great up until about 4500 RPM (just under WOT). At the higher RPM I hear a noise that sounds like a bearing that might be starting to go. Almost a high pitched grinding noise. I'm hoping it's my power steering or alternator... but concerned it coudl something more serious. I'm going to test things out more this weekend (at the house) and pull the alternator and power steering pump to see if that cleans up the noise.

Alternator was bad... but not sure yet if that was the source of the noise at WOT. I ran it in the driveway over the weekend but didn't hear the noise. Tried it in gear as well. It's possible I won't hear it until I have it under a load in the water. I brought the alternator in for repair, they said the stator was bad... likely shorted out from an oil leak I had from the lower unit reservoir. I'm hoping the alternator was the source of noise that I heard on the lake but, the alternator spun freely when I removed it and felt very smooth. I will post later when alternator comes back and I have tested it on the lake.

Regarding second section of post ("However, attempting to align motor...."). I'm still looking for more detail about the motor mounts and whether I need to replace something or not. If anyone has some experience in this area I would appreciate the information. Thx.
 

fat fanny

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Re: Motor alignment incorrect because of incorrect assembly of motor mounts?

On the motor mount issue you got the best advise from one of the best IBoats has to offer. As far as the noise at wot make sure the alternator shop checks it's bearings I wouldn't push it to hard to you resolve that noise issue!
 

nickande

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Re: Motor alignment incorrect because of incorrect assembly of motor mounts?

Fat Fanny, thx for the recommendations. I wont' push it until I know the noise is gone. I getting a replacement "used" alternator. What I am still wondering is if I need to be replacing the rear bushing/mounts or something since I could not get it aligned without putting an extra washer between the motor and gimble mounts (i.e. to raise the rear of the motor slightly).
saying the rear is low could be an indicator that the rear bushings went bad and dropped the rear mounts.
Can these rear bushing/mounts be replaced or does that mean a new gimble or something? How does one tell if these bushing/mounts have actually dropped? I assume putting an extra washer between the mounts is probably proof of that but I was wondering if there is some other indication of that? For example, is there some spec. of where the bushing/motor mounts should be in respect to the top of the gimble? I.E. should the inner metal ring in the gimble be 1/4" above flush, or should it be flush, or some other value?
Thanks for any help.
 

nickande

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Re: Motor alignment incorrect because of incorrect assembly of motor mounts?

Took boat out last Sunday with re-manufactured alternator. Noise is no longer present at WOT. :D Owner of alternator store stated that the alternator can sound like a "bearing going out" when the stator has been shorted out (like it was on mine). So in general I feel the engine is aligned correctly (other than needing an extra washer to raise the rear of the engine slightly). Ending this thread on that note. Will create a new one about the rear transom mounts and what should be done if anything.
 
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