Grease in Stern Tube

[bcguy]

Hi... I am replacing my prop shaft (1.24" normal taper, 58" long for yanmar 27 hp diesel) for my sailboat. There is a grease fitting in the stern tube and grease was pumped into the stern tube as a means of keeping water out. With the new shaft, new stuffing box and flax I want to get the grease out and not use grease as it eventually works its way out and makes a helluva mess. Most of the grease I have pushed out with a broom handle and cloth. Is there any solvent that will dissolve the grease if I fill the stern tube with it and let it sit overnight then drain it out?

Also, I noticed at the exit of the shaft on top and bottom of the stern tube there are 2 screws (one each). I am assuming these are to hold in the cutlas bearing and are not there to be tightened down onto the shaft?

Lastly, there are 2 nuts to thread on to keep the prop on. One is thinner than the other. Which one goes on first?

Many thanks..
Gary

[perchance]

The thick nut first followed by the the "lock nut/jamb nut". If the set screws are meant to lock the cutless bearing you might want to dimple the bearing with a suitably sized drill bit and Locktite in place. Do not overtighten to the point of crushing the bearing. Varsol is as good a solvent as any for degreasing.

[Chief Engineer]

I have seen a couple European built vessels that had very close tolerances between shaft and sterntube. They had grease fittings as there was no cutlass bearing to speak of.

I, am loath, to change original configurations....the grease was put there for some reason. If your stuffing box packing is correct there should be no mess

[tager]

Gasoline should work fine, and cheaply.

[Kapena]

Ever consider PSS shaft seals?

[vintageray]

The Prop Shop in Wilnington just built me a new shaft. It is double nutted and the thin nut goes on first. Looks backwards, but that's the way it is.

[delmarrey]

Originally Posted by bcguy

Hi... I am replacing my prop shaft (1.24" normal taper, 58" long for yanmar 27 hp diesel) for my sailboat. There is a grease fitting in the stern tube and grease was pumped into the stern tube as a means of keeping water out. With the new shaft, new stuffing box and flax I want to get the grease out and not use grease as it eventually works its way out and makes a helluva mess. Most of the grease I have pushed out with a broom handle and cloth. Is there any solvent that will dissolve the grease if I fill the stern tube with it and let it sit overnight then drain it out?

Also, I noticed at the exit of the shaft on top and bottom of the stern tube there are 2 screws (one each). I am assuming these are to hold in the cutlas bearing and are not there to be tightened down onto the shaft?

Lastly, there are 2 nuts to thread on to keep the prop on. One is thinner than the other. Which one goes on first?

Many thanks..
Gary

Just a couple of notes: Why such a large shaft for such a small motor? A 1" shaft should be fine for a 27 HP.

And you want water to get to the stuffing box to keep it cool!

[sdowney717]

yes, thin nut first then thick nut.
seems backwards but that it the way it is supposed to be.

For packing dont use flax, use GFO marine packing. It goes in your current stuffing box and seals better and lasts much longer. It is basically dripless, self cooling and wont score shafts.

[4HMainer]

The grease can also cause stern tube bearings to fail prematurely as it blocks up the water channels which are there for cooling. Grease is a poor conductor of heat, you're right to plan on having the gland lubricated and cooled with water. Many UK boats have greasers but there are also many boats that just rely on water for lubrication and cooling of the packing.