Logo
FULL SITE MENU

Engine alignment question

Bt Doctur said:
Naw, probably they just gave up after all the years, Did you loosen or remove the 2 rear bolts first ?
Changing the rear mounts are not that difficult, we could talk you thru it
Click to expand...

did not remove or loosen anything at the rear. I've been playing around with r for a couple hours now. Things are much better, probably got about half a inch with spline witness marks on it now. But no matter how high or low I have the forward mounts this thing does not want to go in any farther. That's why I'm beginning to think rear mounts.

It's not hard getting back there to those mounts?
 
without that pipe centered nothing is going in . without loosening or removing the bolts you could have overstressed the mounts raising them beyond their limit.
Basically, depending on how your boat is built, you remove the rear bolts, front lags, raise engine up to remove the dust cover bolts,and the rear housing. Burn the inner sleeve out, then drive the outer sleeve out with the correct size soeket.
. Clean the opening with some fine sandpaper, and press the new ones in. I made this to draw them in . But before I made it I used a large C clamp and the correct size socket and thick washer to install them
IMG_1385.jpg
 
Have a job going on right now that the boat has sat for a very long time and the drive was a bear to remove from the dry grease , water and mud in the bellow from clogged hull drains over the years.Drive was reconditioned, new boot kit, gimbal, water hose ,shift cable and low and behold the test shaft is resting on the bottom of the gimbal bearing.
Only there is no access to the motor unless its raised out of the boat. So now to build the scaffold, rig the beam and get to work.
 
Bt Doctur said:
Have a job going on right now that the boat has sat for a very long time and the drive was a bear to remove from the dry grease , water and mud in the bellow from clogged hull drains over the years.Drive was reconditioned, new boot kit, gimbal, water hose ,shift cable and low and behold the test shaft is resting on the bottom of the gimbal bearing.
Only there is no access to the motor unless its raised out of the boat. So now to build the scaffold, rig the beam and get to work.
Click to expand...

Well that is not what I wanted to hear at all! sounds like this is going to get messy. But at least it can be fixed.. I appreciate the information but before i go tearing into that i think ill give it one more shot tomorrow and see what i come up with. I went from little witness "dots" at the tip of the tool to about a half inch of witness lines this evening.

this is the top


and this is the bottom


Based off of this what direction would you attempt to move the forward mounts? up or down?

Really appreciate your help!
 
using the pipe to center it in the gimbal I would go way down on the front.
When you removed the drive did it come off easily? Yes= alignment was good at that point. No= rear mounts had already collapsed
 
Bt Doctur said:
using the pipe to center it in the gimbal I would go way down on the front.
When you removed the drive did it come off easily? Yes= alignment was good at that point. No= rear mounts had already collapsed
Click to expand...

I wouldn't say it came out easy but it came out with just a little effort.. "using the pipe to center it in the gimbal" as in hitting it at the top sides and bottom? Or are you talking about something else?

Tomorrow is a new day, I will give it another shot.
 
805HD, since the rear Engine mounts and the center of the oscilating Gimbal Bearing do not share an "axis", it becomes critical that we perform an alignment procedure. I put these images together several years ago for the Merc, OMC Cobra and later gimbal system Volvo Penta owners.
This may help you understand just why and what we're doing when we adjust the front engine elevation in order to align the "drive coupler" to the upper unit's "propeller shaft" (yes.... technically this is a propeller shaft).

I hope that it helps you.
 

Attachments

  • Drive Coupler alignment explained 3.jpg
    Drive Coupler alignment explained 3.jpg
    51.6 KB · Views: 225
  • Drive Coupler alignment explained 1.jpg
    Drive Coupler alignment explained 1.jpg
    58.9 KB · Views: 268
RicardoMarine said:
805HD, since the rear Engine mounts and the center of the oscilating Gimbal Bearing do not share an "axis", it becomes critical that we perform an alignment procedure. I put these images together several years ago for the Merc, OMC Cobra and later gimbal system Volvo Penta owners.
This may help you understand just why and what we're doing when we adjust the front engine elevation in order to align the "drive coupler" to the upper unit's "propeller shaft" (yes.... technically this is a propeller shaft).

I hope that it helps you.
Click to expand...

Thank you! I understand what im doing or at least attempting to do lol.. all this stuff is pretty new to me so I'm nervous. Plus when it comes to boats I got you guys and a neighbor who thinks he knows what he's talking about. So I'm half way on my own with all of this. That's why I'm very appreciative of this forum and all of you one it.

im going to play around with it today. I made progress yesterday, if I can't get it going today I think it's time to look at the rear mounts.

when I replaced the forward mounts I just raised the front of the engine. Pulled them out and put in the new ones. I didn't even drill new lag holes. I drilled oversized holes filled with 5200 and ran threaded rods down into them. Let the front end back down and it should of sandwiched everything right back to where it was so I don't think it's the forward mounts. At this stage it's got to be the rear sagging
 
805HD said:
....................... and it should of sandwiched everything right back to where it was so I don't think it's the forward mounts. At this stage it's got to be the rear sagging
Click to expand...

It is doubtful that the rear engine mounts have sagged.
However, it may be possible that the inner transom plate has sagged a bit.
If so, the coupler's alignment should still be somewhat adjustable via lowering the front of the engine!

It's all about the geometry in that the center of the rear engine mounts and the center of the articulating gimbal bearing DO NOT share an axis.
If they did share an axis....... we would have little concern for any alignment issues.


.
 
Not so much as "sag" but collapse and it allows the rear of the motor to squat down making outdrive removal difficult.
Thats a sign of bad rear mounts. Once you get the drive off it squats down the rest of the way. Merc says to glue the fibre washer in place but I dont. Once installed if the fibre spins the rear mount is not collapsed.
 
I currently have it to the point where I'm getting even witness marks about 3/4 of a inch down the alignment tool. Slides to that point like butter then just locks up. I'll keep bringing those forward mounts down and see what happens.

1 inch pipe into the coupler is better but still way off center through the gimbal bearing.
 
RicardoMarine said:
It is doubtful that the rear engine mounts have sagged.
However, it may be possible that the inner transom plate has sagged a bit.
If so, the coupler's alignment should still be somewhat adjustable via lowering the front of the engine!

It's all about the geometry in that the center of the rear engine mounts and the center of the articulating gimbal bearing DO NOT share an axis.
If they did share an axis....... we would have little concern for any alignment issues.


.
Click to expand...


ive got another half inch of drop if I'm lucky and at that point the engine will literally be dipping forward! Going off of a 1 inch pipe through the gimbal and snugly into the coupler I can see how much I would have to come up to center and there is no way I have that much adjustment left. Im on it right now. I'll post back with results. But I'm almost certain that something else is contributing to this issue. Like the rear mounts or transom plate as you have stated
 
Engine mounts as far down as I can get them with the wrench I got. Things were moving in the right direction. I can probably squeeze a little more drop out of the mounts but doubt it will get me to where I need to be. Witness marks are about 1'' long now and pretty uniform all the way around. I do feel if I were able to get the front of the engine lower things would line up. But even if i could there is no way this is right...


As you can see things are still not centered, obviously... All this into consideration, where should I begin?


 
Starboard side rear engine mount fiber washer wont spin. Lifted the rear of the engine with a hoist and what do you know... It spun. Assuming I have found the problem?

collapsed rear engine mount.. as stated earlier by Bt Doctur
 
Last edited:
805HD said:
the engine has to come out to replace the rear mounts?
Click to expand...

Yes.

If you pull the engine and look at the mounts you will see that one has sagged.
Question? How far did you jack the front up to replace the front mounts? Is it possible that you bent the rear mount bolts?

Once the engine is out get a socket that fits in the bell where the mounts are and knock them out.
 
Docksidemarineservices said:
Yes.

If you pull the engine and look at the mounts you will see that one has sagged.
Question? How far did you jack the front up to replace the front mounts? Is it possible that you bent the rear mount bolts?

Once the engine is out get a socket that fits in the bell where the mounts are and knock them out.
Click to expand...

dang! I really don't want to pull the engine cause I know I'm going to find a million more things to fix! Haha!

I lifted it a good 2-3 inches it was for sure topped out. I was able to start prepping the engine to be pulled this evening and got the rear mount bolts out. I checked and neither one was bent. That being said I'm sure I caused this problem by lifting that engine to high while replacing those mounts. Which was done the way it was to AVOID pulling the engine!

Live and learn..
 
Last edited:
On some boats you actually have to pull the engine for some service so its good to know how to do it.
On average it takes about 2 hours from start to out of the boat on a stand. About the most difficult part in unhooking everything . start at the front by the fuel line and work around the motor , fuel line, harness plug , front lags, starter cable, exaust sleeve rubber, rear mounting bolts, transom bonding wires, exaust sleeve, front mount, control cables,
using a engine crane across the lifting rings, lift up and out
61hPFB7%2BQfL._SL1500_.jpg
 
Thanks everyone! Is there anything that I should do while the engine is out that might not be so obvious.. ?? preventive wise..
 
why has nobody suggested starting over and lifting the engine from the lifting eye and then gimbaling the bearing.Am I wrong or did this jump straight to rear mounts?
 
bspeth said:
why has nobody suggested starting over and lifting the engine from the lifting eye and then gimbaling the bearing.Am I wrong or did this jump straight to rear mounts?
Click to expand...

not that it means anything coming from me but I think we came to the conclusion that one of the rear engine mounts has collapsed. Based off of me raising the front of the engine to its limits or perhaps even passed those limits to repair and swap out forward engine mounts. Also, port side fiber washer is spinable, starboard side is not. Take some of the engine weight off of it with a hoist and it will spin.
 
I would at least attempt to gimbal that pup before pulling an engine,did you do it before initially checking alignment?
 
Back
Top