Need help removing prop shaft on Hunter 28.5

Richard Bryer · Mar 20, 2012

Haven't pulled the shaft on a 28.5 but suspect it is same as most- you need to remove the coupling flange from the shaft end. Search this forum for "removing coupling flange" and you should find plenty on using bolts and a spacer to press it off.

Johnb · Mar 20, 2012

You are most likely going to have to remove 4 coupling to coupling bolts (see picture) and 2 coupling to shaft bolts. Once the couplings are seperated then the shaft can be pressed out of the aft coupling by placing a socket or something of suitable size in there and bolting the flanges back together.

This is not the time to try and be quick. Do not hammer on things or do anything that transfers the forces to the strut or transmission bearings. Lube and wait if necessary.

mr c · Mar 20, 2012

Johnb said:
You are most likely going to have to remove 4 coupling to coupling bolts (see picture) and 2 coupling to shaft bolts. Once the couplings are seperated then the shaft can be pressed out of the aft coupling by placing a socket or something of suitable size in there and bolting the flanges back together.

This is not the time to try and be quick. Do not hammer on things or do anything that transfers the forces to the strut or transmission bearings. Lube and wait if necessary.

I have found this site extremely helpful. http://www.pbase.com/mainecruising/boat_projects

Ralph Johnstone · Mar 20, 2012

One Member ................................

................. was suffering exactly what you are going through a few weeks ago. I believe his final solution was to cut the damn thing off it was so badly corroded in place. Hopefully yours is not that tight.

Take a look here and this MAY (no guarantees with corrosion) solve your problem

.

http://forums.sbo.sailboatowners.com/showthread.php?p=897315&highlight=ralph johnstone

Let us know what happens.

PS. Welcome to the site and don't be a stranger.

Kite Runner · Mar 20, 2012

Even though you're not putting a dripless shaft seal in...go here.

Good luck!

http://www.pearson35.com/p35articles/documents/PSS.pdf

Sanfelice · Mar 20, 2012

Yes I have done it

I did this project a year ago. First use some PB Blaster and let it sit for some time. Remove the 4 flange bolts and pull the shaft back enough to get a socket between the flange and the transmission. I forget the size, maybe a 7/16 th. Get 4 longer bolts and place them through the flange and the transmission. Put the nuts on and slowly tighten the bolts a little at the keeping the flange even. Alternating the tightening is the key. Not a bad time to replace the nylon stuffing box and hose while you are at it.

Nelsonhow · Mar 21, 2012

Sanfelice is right on.

Apply PB Blaster on all the bolts nuts and in the shaft key way. PB Blaster is kind of like liquid wrench but MUCH bette. Do this several times over a few days. Each time you use the PB Blaster tap the coupling all around with a small hammer. This helps the PB Blaster to penetrate and loosen things up. Cover the end of the transmission with a rag when you spray the PB Blaster so you don't get it on the transmission oil seal. The PB Blaster can damage the rubber in the seal.

After 6 or 7 applications of BP Blaster over several days (time is your friend and allows the PB Blaster to work) and some gentle tapping remove the safety wires and back out the 4 bolds on the shaft. Then remove the bolts between the coupling and the flange on the transmission. Slide the shaft back and insert a socket from you socket set between the coupling and flange on the transmission. The coupling and flange should be about 1/2" to an 1" apart. The distance will depend on how far you can back out your shaft before the prop hits the rudder and the size of the socked you can get in there.

Insert 4 slightly longer bolts and nuts and washers joining the transmission flange and the coupling. Tighten them down a little at a time and the coupling should start to back off the shaft. If not you can use a little heat from a plumbers torch. BUT BE CAREFUL AND HAVE LOTS OF WATER NEAR JUST IN CASE. Use the water in case of fire. Don't use the water to cool hot metal unless it's an emergency. The sudden cooling will make the casted coupling very brittle and might crack it.

Once you've drawn the coupling and flange together is the shaft is not loose you may have separate the coupling and flange and do a second or third round with a larger socket.....

Be careful because if you break the flange on the transmission you'll be in deep do do. This will probably work but you may wind up having to cut the shaft and replacing it.

Warren Milberg · Mar 21, 2012

The above advice to remove the shaft is pretty much what I did when I replaced the OEM plastic packing gland on my boat a few years ago. Once I got the shaft free of the coupling, I dropped the strut and took the whole thing (shaft/prop/strut) home to work on in my basement since I was also replacing the cutless bearing (you should consider too this since you are pulling the shaft). Finally, I'm sure you mean to replace the OEM gland with a bronze one, not a brass one. Good luck with this.

Robert580 · Apr 8, 2012

Local boat yard should help with replacement parts.
before you cut the shaft look to see if the coupler has splits where it is bolted to the shaft, if so, drive a couple of wedges in the split, this will loosen the pressure ever so lightly which amybe enough to remove the coupler.
I just did this on my shaft seal replacement.
My boat is a 1985 which maybe a different style then yours.
Good luck

Nelsonhow · Apr 8, 2012

You can try a little heat form a plumbers torch

but it's not that uncommon for the flange not to come off. Cutting the shaft is an easy solution if it's a brass/bronze shaft but a little more difficult if it's stainless. You'll still have the issue of getting the new shaft back in if the rudder interferes. Sometimes there is enough play to get it in without moving things but if not and if you're replacing the stern tube fitting you can leave it a little loose to give you some adjustment room, or you can loosen the strut. Remember to tighten tme before you slash the boat.

But try the heat..... you'll be surprised how it loosens things up. (KEEP A HOSE READY IN CASE)....

robertsapp · Apr 9, 2012

GregBeaver said:
Many hours later I'm still unable to get the coupler off the shaft. I have tried for days by using PB Blaster and patience. It simply will not come off the prop shaft. I'm now considering cutting off the prop shaft coupler and putting a new one on.

Does anyone know where I can purchase a replacement?

Thanks,

Greg

A coupler isn't really something you just put on. You take the shaft to a machine shop where they press it on and then machine it so that the face is perfectly perpendicular to the shaft axis. If you bang one on yourself there's a good chance you'll get the face angle slighly off and then you'll never be able to get rid of the resulting vibration.

If you want to replace the coupler without damaging or destroying the shaft, you need to pull the prop, unbolt the shaft coupler from the transmission, unbolt the engine from the mounts, raise the engine with a hoist, and then pull the shaft into the boat. Then take the shaft with attached coupler to a machine shop and have them press it off. Of course, if all you want to do is install a new stuffing box, then once the shaft is out, you can install the new box and reinstall the shaft and skip all of the fussing with the coupler.

Your boat is out of the water I assume?

Need help removing prop shaft on Hunter 28.5

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