Rear oil seal replacement

[JackConnick]

Hi;

I'm getting quite a bit of oil being flung around the shaft coupling. Looks like the coupling/rear seal need replacement.

I've watched Don's video and read a few of the threads here.

Questions:

I have a dripless stuffing box. Are there any complications to move the shaft aft after it's disconnected?

How successful is using a pipe wrench to hold the coupling while getting the nut off? Do I need the special tool?

Will the engine/shaft need alignment when I'm done? I don't have any particualr issues right now.

I have an electric wrench that has pretty good torque. I have very poor access to the back, I can only get one arm in... arggh.

Jack

[Peter]

Jack,

I did this job 2 years ago.I also wanted to replace my engine mounts, so I pulled engine into salon to do it. With that access I used an electric impact wrench to loosen the coupling and it worked like a charm.

If you have watched the video then I think you are aware that sometimes the output coupling itself is messed up and replacing the seal is to no avail. Moey sells new couplings or a sleeve for your existing coupling.

Naturally, I had to realign engine and with the new mounts that was also very simple to do.

No experience with dripless stuffing box i am afraid.

Peter

[JackConnick]

Yes, planning on replacing the sleeve. The shaft coupling doesn't look like it's too badly rusted together.

I'm wondering about just putting the engine in gear to hold the coupling while loosening the nut...?

Jack

[Peter]

Engine in gear - did not work for me but worth a try

Peter

[JackConnick]

I tried to get the shaft coupling apart, but couldn't get a pipe wrench to hold it. Every time I tried the wrench just swiveled and fell off.

I have pretty poor access and can't really get two arms in to hold it.

I was think about something like a c-clamp or something to jam it with?

Any ideas?

Jack

[Hawkeye54]

Jack, do you have access to a large 'C-clamp' that you could perhaps modify by welding a piece of channel ? Like this : (----< ]) - I am sorry, but I do not have the skills to post pictures.



Rick

[JackConnick]

Thanks, I don't have the facilities to weld.

[JackConnick]

FWIW;

I decided that I was going to get in over my head with this repair and took it into a mechanic. Sometimes you just gotta know your limitations...

The mechanic had a heck of a time, there's very poor access you can only get one arm in. He couldn't get the coupling off the tail shaft. Ended up taking the entire rear case half off along with the tail shaft to get it into the shaft and pressing it out with a vise.

Ended up costing me some $$$, but it's done now.

Btw, the way to hold the shaft is to put an old zinc on it and then secure with a pipe wrench. I had to dive on the boat to remove the zinc on the outside shaft.

Jack

[Al Schober]

First, the dripless seals have a half that's fixed to the shaft - usually by a set screw. To slide the shaft aft you have to allow that half of the seal to slide fwd - hopefully without damaging it's o-ring..
Second, the output flange from the transmission is just a steel casting and will corrode. Corrosion on the surface that the seal rides on will destroy the new seal in short order. If the surface is corroded, our host sells a sleeve that can be pressed onto the existing flange and will restore a good sealing surface. This is an easy job for a good machine shop - not sure I'd try it at home.