Volvo Penta engine coupler runout … aka wobble

[highpowerdad]

I picked up a VP 2006 5.7 GI motor with the intention of putting it in a project boat…it is in great shape, however… the engine coupler is “wobbling”. When I measure the runout of the coupler HOUSING (not the spline, but the outer metal housing, on the diameter, at the aft most edge, measured to a common reference point as I rotated the engine), I get .040” of radial movement, so .020” from “concentric” IF I take angle measurements, I get a change of about 0.3 degrees on the aft face of the coupler as I rotate the crank, so, again, an error of about 0.15 degrees from the normal, which, doing the trig, is the same .020” change, so it is a “Wobble”.

This doesn’t seem right, but I have no reference point as to what is good and bad…

SO, is this, ok? Will it cause vibrations, damage bearings? Is this possibly a bad coupler or, worse, a bent engine crankshaft? This engine was pulled from a boat that was in a road accident. The boat was not hit but came off of its trailer when the trailer went off the road into a ditch, the gimbal ring was broken from transom at the top pivot, I assume from the inertia. I had also assumed that with the U-joints and the rubber coupler in line, the engine crankshaft was protected, now I am not so sure. Any insight is appreciated.

Thanks
Scott R.

 

[Scott Danforth]

first, make sure the coupler is mounted properly.

then make sure you are looking at the hub

you dont have a bent crankshaft. forces required to bend the crankshaft would have broken the block

 

[Lou C]

Maybe remove the coupler and make sure nothing of off with the mounting also you might be able to check the run out of the flywheel where the coupler mounts…

 

[highpowerdad]

first, make sure the coupler is mounted properly.

then make sure you are looking at the hub

you dont have a bent crankshaft. forces required to bend the crankshaft would have broken the block

Scott D, Thanks for your insight, So, I am pretty sure this would be the original coupler, as it doesn't look like the bell housing has ever been removed, I guess the best thing to do is remove the bell housing so I can really see what is going on and spin the motor. Any tricks to removing the bell (assuming that is what it is called on a boat?). Also, since you didn't say "that is normal" I guess I am looking for what is bent or not aligned. I can't really get a good measurement off of the hub itself, but if the metal housing of the coupler is wobbling, I would assume the center hub is wobbling also.
Scott R.

 

[alldodge]

Support the rear of the motor and than remove the bolts holding the bell housing

 

[Scott Danforth]

Pull drive
Disconnect the motor
Then pull the motor
Then remove the bellhousing

 

[bruceb58]

If it were my boat, I would be putting in a new coupler.

 

[highpowerdad]

All, sorry if I wasn’t clear in the original post, the motor is NOT in the boat, so I have full access to work on it. I was wondering if anyone had seen this wobble of the coupler on their past experiences, and what was “normal”. Since the engine was from a boat that was involved in a road incident, I was concerned that maybe the crank was bent. So, now that I know I need to figure out what is going on, first thing is to remove the bell housing, anything special about doing that? Support back of motor, from lift ring or can I have a block under the oil pan? Remove starter first, or it can stay? Is the a gasket around the top of the bell that needs to be replaced? I assume the front close out piece needs to come off so I can clear the flywheel. Looking for guidance so I don’t reinvent the wheel…I know some of you have done this several times, this is my first rodeo. I do have a shop manual, I will need to take a look at that also.
I’m gathering the information before dive in, thank you for sharing any experience you have.

 

[Bondo]

All, sorry if I wasn’t clear in the original post, the motor is NOT in the boat, so I have full access to work on it. I was wondering if anyone had seen this wobble of the coupler on their past experiences, and what was “normal”. Since the engine was from a boat that was involved in a road incident, I was concerned that maybe the crank was bent. So, now that I know I need to figure out what is going on, first thing is to remove the bell housing, anything special about doing that? Support back of motor, from lift ring or can I have a block under the oil pan? Remove starter first, or it can stay? Is the a gasket around the top of the bell that needs to be replaced? I assume the front close out piece needs to come off so I can clear the flywheel. Looking for guidance so I don’t reinvent the wheel…I know some of you have done this several times, this is my first rodeo. I do have a shop manual, I will need to take a look at that also.
I’m gathering the information before dive in, thank you for sharing any experience you have.

Ayuh, a block of wood under the pan will work, 'n the starter can stay put,....
pull the little cover off the bottom of the flywheel cover, then the bolts holding the flywheel cover to the block,....
At that point, the flywheel cover can be removed,...
No gaskets involved, atleast on a Merc,.... not sure on a Volvo, but I doubt it,....