Driveshaft Coupler

[Euphrates]

After replacing my exhaust, I figured I'd tackle the stuffing box while in the area. It took me seven hours to break the two nuts loose and it's ready for some GFO. As soon as WM opens!

In the mean time, I noticed that the piece that connects the driveshaft to the transmission is in pretty rough shape. What is this piece called and can I replace it without hauling out? Picture at the bottom. Any other concerns you have are welcome.

Thanks for all of the wonderful help over the past few days. There should be a button I can press to buy each of you a beer.

[tenders]

That, my friend, is the driveshaft coupling or coupler, and you're correct that yours looks tired. Moyer sells a replacement "split shaft coupling" that you should absolutely use when you replace it - it is quite revolutionary for maintenance purposes once it's installed. However, pressing that existing rusty ba$tard off the shaft in the limited space you have between the stuffing box and the transmission is not a casual project - lots of details exist on this here. For me it is the single nastiest and least-rewarding job I've ever done on a boat. And once it's off, the new coupler should probably be mated to the shaft by a machine shop (though mine was not and seems to be fine).

Personally I would treat yours in place with a wire brush and some of that rust stabilizer that turns rust black, and let that sleeping baby lie for another time. There is plenty of metal on that piece for the relatively modest job we ask it to perform with our A4s.

[Tim]

I would replace the hose clamps on the stuffing box hose and the hose should have two clamps on each end.

[Euphrates]

I'll do the maintenance and put off a swap.

Yeah, the condition of stuffing box and exhaust assemblies blew my mind because the PO owns a very successful and reputable plumbing company in town. You should see the gate valves on this baby, too!

[JOHN COOKSON]

Also the thin lock nut should be against the packing nut to hold it in place.
What is the drip rate? I hope the packing is not running hot. This can score the shaft.To test put your finger on the packing nut while the shaft is turning at cruise RPM. It should be the same temp as the water the boat is in. Be careful around moving machinery.

BTW have you noticed that working on the engine on a Cat 27 is like doing marine engine maintenance and repair down a gun barrel?

TRUE GRIT

Edit: Before you try to break the packing nut\lock nut loose hit it with PB blaster or your favorite goop for a couple of days.