Prop Shaft Coupling Removal

[sailcail]

I’m looking for advice on removing the shaft couplings on a 2002 366 Aft Cabin. I need to remove the couplings to replace the shaft seals. The boat has 6.2L Mercrusier engines. I have removed couplings on other boats in the past but they all had set screws, there are no set screws on the couplings so I’m wondering what holds the couplings to the shafts.

Thanks,
Simon

[waybomb]

Look to me that you clean up the shaft, remove the bolts, and slide the coupling up the shaft. The key isn't going to walk out with the keyway broached as in the picture.

I like the idea of no set screw. Nothing to displace the metal where the screw sets.

[km1125]

I think some have a nut on the end of the shaft inside the coupling. You'd have to take the four coupling bolts loose and slide the shaft back to get to the nut.

[bud37]

Here is the parts blow up drawing.....section 14.4 to 14.6......section a-a....


https://carveryachts.blob.core.windows. ... ual_03.pdf

[sailcail]

Thanks guys,

I can see from the parts diagram that there is in fact a nut on the end of the shaft that holds the coupling on. Looks like it won't be too hard to remove it.

Do you think its worth replacing the entire shaft seal with a new PSS seal kit or just replace the lip seal in the current Tides unit?

[Viper]

You usually need a thin walled socket for the Nylock nut inside the coupler. The nut will be recessed and is not easy to get out without a socket. You'll then need to push the shaft through the coupler by inserting something that will force the shaft out as you re-tighten the coupler back on to the tranny flange. Or fasten the coupler to the flange, remove the prop and use a puller to pull the shaft back.

[sailcail]

Viper,

Thanks, from the part description it looks like I will need a thin walled 1-1/2 socket. I’ll get some longer bolts and put something between the coupler and the flange, as you suggested. How about getting the coupler back onto the shaft? I imagine it’s a tight fit.

Thanks,
Simon

[Viper]

It will slide in, the shaft there is tapered just like the prop end. Clean the mating surfaces with a Scothbright abrasive pad or equivalent, you don't want to remove any metal. The shaft will pull in as you tighten the nut. FWIW, it's a good practice to replace that nut after it has been removed but a lot of people don't bother unless it's obvious it's that worn....it's your call. Any good prop shop will have them in stock.

I would just replace the the lip seals in your current ones. They are good units. The PSS units in the pic are a different type of dripless logs that work on a different principal; face seal. There are pros and cons to both designs. If you stick with the Tides, buy yourself two sets of seals per side and the housings for the spare seals for mounting on the shafts. The spare seal assembly will bolt to the shaft between the log and the coupler. This will allow you to replace the seals without removing the shafts next time. Make sure they send you an install sleeve and use it when installing the seals so they're protected when you slide them on to the shaft.

[Midnightsun]

That is what I did after my "incident" this summer. New main lip seals and spare seal mounted on shaft for future change.

[sailcail]

Ah, I completely understand now, it’s tapered just like the prop. That’s a great design, much better than the set screw type. I will get a new nut and install a spare seal/housing. I will post some pictures when I’m done.

Thanks again for all of the info,
Simon