Shaft Log Replacement

[homer12]

I have a pretty worn looking shaft log and I need to replace it before it cracks and I get big problems. My shaft alignment seems pretty good right now and I'm not trying to tackle that any time soon.
If I disconnect the shaft coupler from tranny and pop off the flange, should I be able to just bolt it all back up without needing to do an alignment?

[TRBenj]

I assume you mean "shaft log hose" and not the shaft log itself, which is made of brass and usually fiberglassed right to the boat.

Replacing the log hose will have no effect on alignment (only strut location and powertrain placement will)... but the fact that you said it "seems pretty good" means its probably overdue. Why you would try to avoid checking it while everything is apart is beyond me.

[psychobilly]

There's a member that just completed this task. You may want to search for this topic... There's a coplete write up on this.

[psychobilly]

Double Post because of the VERY SLOW internet here in the South China Sea.... Sorry....

[homer12]

I guess what I meant by pretty good is that there is no gaps anywhere between the coupler flanges and get no vibration under power. For my knowledge, that would mean alignment is good to me, but maybe I'm missing something.
Yes, I did mean the shaft log hose, my bad. I've researching the shaft alignment in case that is necessary.

[FrankSchwab]

Reseach done!

PROPSHAFT_ALIGNMENT-15676.doc

But, yes, you should be able to bolt everything back together without affecting the existing alignment. But taking off the coupler and separating it from the shaft is a reasonably big job; spending an extra hour to line everything up while you're working on the shaft already seems like a really good choice to me.

[FrankSchwab]

Oh, and you'll probably need to replace the packing once you pull the stuffing box off the propshaft. Order it with the other stuff - 3/16" for 1-1/8" shafts, 1/4" for 1" shafts.

[TRBenj]

Originally Posted by homer12

I guess what I meant by pretty good is that there is no gaps anywhere between the coupler flanges and get no vibration under power. For my knowledge, that would mean alignment is good to me, but maybe I'm missing something.
Yes, I did mean the shaft log hose, my bad. I've researching the shaft alignment in case that is necessary.

I assume you are looking at the 2 flanges when they are mated or bolted together? If so, that is meaningless, as those bolts can hide gross misalignment (1/4" +).

Misalignment will also not cause any vibration at speed. The excessive side loading of both the shaft within the strut and transmission internals will not cause any outward symptoms, save for uneven strut bushing wear and premature transmission failure. Nothing you can easily see or hear underway though.

[homer12]

Thanks fellas! I'm now convinced that when I get it disassembled I'll be checking all the alignment now and making adjustments as necessary. Doesn't sound too difficult, but maybe just time consuming because of a learning curve.
I plan to replace the shaft log hose and repack the stuffing box and get the shaft alignment done.

[FrankSchwab]

You have joined the path of wisdom, my son. Soon your latent MCOCD will be more powerful than you could imagine!