Engine & Prop Shaft Removal

[Lateralus]

I'm pulling the 33 year old Penta MD17 from my boat to rebuild it this winter. The yard said the coupling will need to be broken and the prop shaft pulled to be able to pull the engine. Is this standard operation? I would think one can disconnect the prop shaft and pull the engine without pulling the shaft. Thanks ahead for your opinions!

[Sailmonkey]

I've had to slide shafts back, but never pull one out to remove an engine.

[DeepFrz]

Yes, you can do it that way.

[Blue Stocking]

I've worked on them where the engine was up under a bridge deck and to get it far enough aft to lift out, we had to remove the packing gland.

[propellanttech]

Originally Posted by Lateralus

I'm pulling the 33 year old Penta MD17 from my boat to rebuild it this winter. The yard said the coupling will need to be broken and the prop shaft pulled to be able to pull the engine. Is this standard operation? I would think one can disconnect the prop shaft and pull the engine without pulling the shaft. Thanks ahead for your opinions!

This is very dependent of the front pulley of the crankshaft, and how close it is to any structure that can not be moved.

I personally think, if you move the shaft, you should pull it out and have a look at it. It's not much more work since your there anyway. It will give you a chance to look things over, like your cutlass bearing. Also if you have a packing glad, you can check for shaft grooving.

If you don't need to move it, you can opt to leave it alone, but I probably wouldn't go that route. Better to do anything needed in one step, than have to haul out again for a shaft problem 6 months later.

Just my opinion, your mileage may very.

James L

[Cotemar]

Originally Posted by Lateralus

I'm pulling the 33 year old Penta MD17 from my boat to rebuild it this winter. The yard said the coupling will need to be broken and the prop shaft pulled to be able to pull the engine. Is this standard operation? I would think one can disconnect the prop shaft and pull the engine without pulling the shaft. Thanks ahead for your opinions!

Most times you just slide the prop shaft back until the coupling hits the stuffing tube.
They must need the room. Its usually not that much more work to slide it out all the way. Just have to take the shaft coupling off.

[Cheechako]

I think it would be rare, but if you're pulling your engine, pull that shaft and look at it, alot of shafts are worn or corroded bad inside the stuffing box where you cant see.

[Sailmonkey]

Originally Posted by propellanttech

If you don't need to move it, you can opt to leave it alone, but I probably wouldn't go that route. Better to do anything needed in one step, than have to haul out again for a shaft problem 6 months later.

Just my opinion, your mileage may very.

James L

It's funny how minds work differently. I never think about being hauled out for engine work..........

[propellanttech]

Originally Posted by Sailmonkey

It's funny how minds work differently. I never think about being hauled out for engine work..........

Ha......

I'm pretty sacred of finding my future (don't own right now) boat in the slip sitting on the bottom.

Yes engine work can be done while wet, but I'm always scared something may happen. I am a drip less seal guy, so that does play a part in the process. With a packing gland, there is less chance of "flag pole above the water" syndrome.

Still, I try not to tempt fate.

James L

[Irish rambler]

I guess your yard is looking to pad the bill !. Why lift the boat out to remove an engine ? Any shaft maintainance can be done when you normally lift the boat to anti foul.

[propellanttech]

Originally Posted by Irish rambler

I guess your yard is looking to pad the bill !. Why lift the boat out to remove an engine ? Any shaft maintainance can be done when you normally lift the boat to anti foul.

I would do that too (bottom work).

No, the boat yard doesn't do it for free, nor do they pay for it. It isn't all that expensive, at least at the marina I'm accustom to.

I'll give you an example of what can happen: what if after the engine work is done, you or a tech finds a shaft misalignment. Guess what, you will have to haul the boat to fix the problem. So you didn't save any money, just wasted time.

There are many times a haul out is not needed. If I just put the boat in the water, and needed an engine rebuild, I wouldn't haul the boat. I would just do some precautionary measures to insure no "flag pole from the water" event.

But this is a good time to check through hulls, shafts, rudder bearings, zincs, prop, etc. It's not like your going to use her while the engine is out. You could, but most won't.

James L

[rocksculpter]

Shaft/engine alignment is done in the water because hull distortion will be different when out. You should be able to reinstall where it was if you don't mess with the engine mount adjusters. I personally haven't seen a boat that needed to be hauled out to remove an engine. If you have a dripless seal be sure to support the shaft about in the center, you'll be able to tell by how much, if any, leakage will occur.

[propellanttech]

Originally Posted by rocksculpter

Shaft/engine alignment is done in the water because hull distortion will be different when out. You should be able to reinstall where it was if you don't mess with the engine mount adjusters. I personally haven't seen a boat that needed to be hauled out to remove an engine. If you have a dripless seal be sure to support the shaft about in the center, you'll be able to tell by how much, if any, leakage will occur.

Not all shaft alignment is done in the water. If the strut is misaligned, it will be corrected on the hard. I've never seen a strut misalignment done in the water. I have seen engine alignment done in the water, but that is different.

James L

[perchance]

A quick glance at the under body tells me you may have to remove the rudder to get the shaft out unless it is an offset shaft or it comes out forward into the engine compartment. If there is no compelling reason to pull the shaft I would leave it alone.

[boden36]

It would be wise to sit down on the boat with the person who will be in charge of the job, and get him to walk you through it step by step, explaining and justifying each bit as he goes. That should answer your question.
Regards,
Richard.