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Removing an OMC Stern Drive from a Buick 225 V6

T

the_tassie_devil

Regular Contributor
"Hi all,

I am trying to sep

"Hi all,

I am trying to separate the Stern Drive unit from the Bellhousing of the 225 Buick V6 in my 1972 Chris Craft Sportsman 16.

I have undone all 16 nuts and supported the weight of the Stern Drive but cannot lever the two apart.

Is there something inside the Bellhousing that has to be undone before the Stern Drive can be removed?

Or, do I have to remove the engine at the Bellhousing first. Then remove the Bellhousing from the Stern Drive?

Thanks in anticipation.

Bruce Reynolds,
Tasmania,
Australia"
 
first you remove the drive fro

first you remove the drive from the intermediate.
Then you can try to separate the intermediate from the engine's bellhousing. The splines of the intermediate may be rusted into the splines of the coupler on the rear of the crank. You may have better luck trying to pul the intermediate shaft out the back of the intermediate housing. A puller can be used to draw it straight out. Try to aim some good penetrating oil into the coupler from underneath the bellhouing and let it soak for a day or so.
Resist temptation to pry the aluminum housing - it's weak. breaks really easy.
 
"G'day Hy Stat,

Thanks

"G'day Hy Stat,

Thanks for the quick reply.

Is there anything within the Bell Housing area that is likely to stop the OMC part being simply drawn rearwards?

I cannot find any diagrams of what is actually in there. But, I am surmising that there is some form of "Drive Plate" attached to the flywheel to accept a splined shaft that extends to the OMC unit. Am I correct here?

Thanks,

Bruce."
 
"Now, further investivating, v

"Now, further investivating, vis a hole I drilled into the Bellhousing, I see that the Drive Shaft appears to be bolted to the Crankshaft Flange via the same bolts that secure the Flywheel to the Crankshaft.

Now, is there a way of undoing the couplet further back without having to completely disassemble the leg where it passes through the transom?

Thanks,

Bruce."
 
"[b]"Now, further investiv

""Now, further investivating, vis a hole I drilled into the Bellhousing, I see that the Drive Shaft appears to be bolted to the Crankshaft Flange via the same bolts that secure the Flywheel to the Crankshaft."

They're NOT bolted together there,...
It's a splined coupler,...
I'm guessing your's is Rusted, Solid...."
 
did you see where I put:
[i]T

did you see where I put:
The splines of the intermediate may be rusted into the splines of the coupler on the rear of the crank. You may have better luck trying to pul the intermediate shaft out the back of the intermediate housing.
 
"Sorry for being a pain, but a

"Sorry for being a pain, but as usual, I don't have the complete Workshop Manual for the part that I really need to see.

That is, the area between the Engine and the actual Stern Drive that passes through the transom.

Is there anywhere that I can access a diagram of what the Coupler actually looks like, as the part that I am loking at inside the Bellhousing, through the hole I drilled, does not look like a Splined area, and looks like a Machined Flange, tapering down to the shaft.

Further, is the spline hidden by the exhaust chamber inside the Bellhousing? If so, then this is why I cannot observe it.

One of those times when I would really like an Endoscope.

Bruce."
 
"Bruce...not sure if these par

"Bruce...not sure if these parts pics might help of the crancase and the intermediate

http://www.marineengine.com/discus/messages/12488/248787.png"" alt="""">

[img]http://www.marineengine.com/discus/messages/12488/248788.png"" alt=""
 
"Thanks Bob,

I have drawn t

"Thanks Bob,

I have drawn the image of what I can actually see through the 1" hole I drilled and the "Coupling" looks nothing like in the diagram you posted.

I imagined that it should look like what is in your diagram, but alas not.

Any further clues, apart from trying to undo the flywheel bolts from underneath, after I remove the bottom Engine Mounting crossmember.

Thanks,

Bruce.

248802.jpg
225 Bellhousing
 
"G'day Hy Stat,

That&#3

"G'day Hy Stat,

That's it, that's what mine looks like, and I just cannot see the end of the coupler, but managed to "Feel" the step down to the shaft with a length of wire, suitably bent.

Now, for the "undoing of the bolts at the crankshaft from underneath" trick.

Will advise when completed, after I have been to the Out-patients Department of the local Hospital having suitably recovered from contorting into the many unfamiliar positions I will have to get into to get down there.

Bruce."
 
"G'day Bondo, Hy Stat and

"G'day Bondo, Hy Stat and Bob,

I gave up on the "Remove the Crankshaft Bolts" as the Bellhousing doesn't let anything up from underneath, without major surgery to the Bellhousing.

So, off with the Leg. Yes, it was as easy as I thought it would be.

Now, I see from the drawings I have that the rear drive fingers on the intermediate shaft are shown as being fastened to the intermediate shaft by a nut on the end of the shaft.

Well, when I removed the Welsh Plug, there is no nut there, just the end of a shaft that is simply splined to the finger gear.

If this supposed to be a slip-fit, or a "Press Fit" as it won't come off with careful use of a slide hammer. (yes, I undid the three bolts holding the bearing retainer flange)

Apart from putting an oxy tip inside the bellhousing hole to apply heat to the coupler to expand it a bit, is there any other method that you can think of to get this coupling apart?

I am yet to try the Puller as I am going to acquire a two-prong puller. My other pullers won't fit.

Oh, I cannot pull the unit through the transom and out with the engine as the engine enclosure won't allow it.

Bruce."
 
"Ayuh,...

The last 1 I did

"Ayuh,...

The last 1 I did that was Siezed like that,...
I pulled the motor,+ drive section out of the boat,+ when I dropped it onto the ground,...
It Split appart..."
 
"At what height did the "D

"At what height did the "Drop" start from?
biggrin.gif


I definitely would pull the unit out if I could without having to cut the fibreglass cowling, but that will be a last resort.

Bruce."
 
"Gentlmen,

Is there any oth

"Gentlmen,

Is there any other fastenings apart from the 14 Stud/Nuts that are around the Intermediate Case to Bellhousing?

I have undone all the fastenings that I can see, and the Intermediate Case is "Loose" if you can call it that, from most of the way around the mating surfaces, apart from the bottom Right Corner.

It seems to be still tight there.

Do I have to remove the Steering hub that the cable goes around?

Something is still holding it together in this area at the bottom.

Further, I have removed the Drive Finger gear from the Drive Shaft Spline, and I am seeing a Tapered Roller Bearing, but no amount of careful persuation with a Grass Drift will move the Shaft forward.

Further, I have tried the soaking method, and hammering the side of the Coupler withg a long drift through the previously-drilled Inspection Hole to shock the rust into submission, rotating the crankshaft a bit at a time. But, still no separation.

I am starting to get desperate now, and I don't really want to do the patented "Bondo Dropping Method" of separation.

Bruce."
 
"you need to adapt a slide ham

"you need to adapt a slide hammer to the intermediate shaft to pull it out the back.
Not threaded though? That will make it tough. If you wreck the shaft you are done. No more of those in the world.
I have removed the adjuster screw out of pair of vice grips before and adapted/threaded the puller in it's place to make a clamp on slide hammer, but not good for much impact as you're kinda pulling on about a 15 degree angle. But could weld onto a set of vice grips and maybe grab the end of the shaft with them.
too bad it's 72..1973 would have the ball gear held on with a nut.

Are we sure this drivetrain is worth saving?
On this side of the earth, a whole boat in excellent running condition with that engine and drive is worth about $100."
 
OMC never trusted boat builder

OMC never trusted boat builders to put the engine and intermediate together in the boat.

The engine and intermediate must've went into the boat in 1 piece at the factory. It should be able to come out in 1 piece. Unless someone has built some additional structures around that area.

I think I'd eye up what could be cut/modified inside the engine bay to facilitate pulling the engine/intermediate out as a unit.
 
"[b]"If you wreck the shaf

""If you wreck the shaft you are done. No more of those in the world."

Ayuh,...

Isn't that the Same shaft that comes into the coupler,..??

If So,...
I gotta believe the Rusted, Siezed end is Already Trashed....

The 1 I took apart by Dropping it,...
That shaft was Soo Rusted,..
The Splines were Barely there,+ were Not servicable...."
 
"yeah, all one shaft....

it

"yeah, all one shaft....

it's NLA

that Buick coupler is also NLA

evilbay the only way and I never see them there."
 
"Well, if Bondo would finally

"Well, if Bondo would finally put out a video on how-to re-glass the ass-end we could all switch to Merc's. A Google search reveals you as the master of this technique Bondo. How's about it buddy? Can you video the next one you do?

248881.jpg
"
 
"Well, not what I really wante

"Well, not what I really wanted to hear, on all sides.

If the boats are that cheap, maybe I had better buy a half a dozen and fill a couple of containers.

But, seeing as I am used to restoring the impossible, I will now treat this task as a "Project of Significance" and proceed with caution.

Looks like the Bellhousing will be receiving some good ventilation slots, that will allow access to the crankshaft bolts. At least I can then weld the bellhousing up later on, and if necessary, machine up a new coupler.

Anyone got any replacement Finger Gears?

Bruce."
 
"[b]"How's about it bu

""How's about it buddy? Can you video the next one you do?"

Ayuh,.. Probably Not... I'm a Mechanic, not a vidiographer..

I Have written about it more than just a few tmes though....

I've got more than a 1/2 dozen under my belt,+ 2 more in the works, at the moment.."
 
"<[img]"http://www.marineengin

"
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is there not some way of putting some heat to the shaft at the coupler ? You said that you can weld the bell housing later. Just a thought.
Good luck hope something works for you.

Frank"
 
"G'day Frank,

I am goin

"G'day Frank,

I am going to do that in about a week's time, after I have completed another task that needs to be done first.

What I plan to do is pull the engine and Intermediate box from the hull as a unit, twisting and turning it as need be, and it looks like I will be lifting the unit rear end first.

Then, from underneath, or on top, when I turn everything upside down, after draining all the fluids, then cut away the bottom of the Bellhousing, where it won't interfere with the mounting bolts, and cannot be seen from on top, then attack the coupler with the said Oxy, or undo the flange mounting bolts to the Crank and soak the back of the Coupler whilst it is on its' end.

The hole I have already drilled will receive a plug so I can have future access if necessary.

This boat is a keeper, even though it is a Fibreglass Chris Craft, as as far as I know, it is the only one of its' kind here in Tasmania. A couple of timber ones, but no Glass ones. Could never aford a Wooden one.

Will definitely post pictures of the attack.

Bruce."
 
"Gentlemen,

Is it possible

"Gentlemen,

Is it possible to remove the Steering Drum from the Intermediate Case with the case in position, or do I have to remove the Steering Cables from the Steering Wheel and Tensioner Spring and let the cables hang off the Drum until I remove the Case from the Bellhousing, after getting it all out and onto the ground?

Thanks in advance.

Bruce.

PS. This is all that is holding me up from the extraction process."
 
"[i]Is it possible to remove t

"Is it possible to remove the Steering Drum from the Intermediate Case

Yes

don't touch the cables, that would be a spaghetti nightmare. the whole drum assembly detaches

remove the outdrive, then take the screw out of the drum (turn the steeringwheel until you see it - slot screw) and then take the bracket off and slide the shaft (#75 in pic above) out the back (that's why the drive has to come off)"
 
"Thanks Hy Stat,

The only &

"Thanks Hy Stat,

The only "Bracket" that I can see stopping me from doing the shaft removal is what appears to be a Collar, immediately behind the Drum, with what appears to be a Roll Pin through the centre.

I have attempted to carefully drive this pin out, but it doesn't seem to want to move. It is soft, and simply wants to squash up.

I cannot see what "Bracket" you are referring to.

Bruce."
 
"Further, the afore-mentioned

"Further, the afore-mentioned Collar is at the rear end of the Drum, and not at the Forward end as shown in the Diagram.

Bruce."
 
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