volvo stern gland

[djs]

I am replacing the volvo stern gland as it is beyond its 'official life' but more importantly allows in a steady trickle of water when under motor. I had no knowledge of how it was all arranged so carefully undid everything last weekend and separated the bits. The boat is out of the water! apologies if the following description is confusing, I wasn't sensible enough to take photos.
The outboard end of the solid rubber tube was pushed onto a brass cylindrical block that was then secured to the stern tube using a short length of reinforced neoprene hose with a couple of hose clips. (i'll put two on each end when reassembling)
The brass cylinder appears to just be a solid lump of metal not a housing for any bearings. this metal lump 'rattles' on the prop shaft with about 2mm of clearance. i assume that there should be some space between the shaft and block to allow water to reach the lip seals in the stern gland but was surprised by the amount of play between the two. Should I be concerned? Part of the worry is that the engine mounts were loose when I bought the boat leading to lots of vibration and I am worried that this may have caused some damage. It's a 1 inch shaft on a flexible coupling to a hurth gearbox and a Beta 1005 28hp engine.
any thoughts and experience of the same gratefully recieved.
many thanks
Dave

 

[GeorgeTina]

My Beneteau First 305 has the same setup with lots of movement where the shaft goes though the hull. Have always assumed that it is designed like that and have owned the yacht for five years with no problem (other than a gearbox whine when going forward). So it will be interesting to see other responses you receive.

 

[MoodySabre]

You might find this interesting:
http://www.ybw.com/forums/showflat.php/Cat/0/Number/650722/an/0/page/24

 

[achwilan]

The vibrations you mention seem odd, as they may damage the lips of a Volvo rubber stern gland: the early death of that part on my former Bénéteau 311 was a result of a defective cutlass bearing, and the subsequent vibrations. The rather flexible mounting you point to is probably some mitigating solution, but may be you should take some action about the (tired?) engine mounting/silent blocks.

 

[djs]

moodysailor, thanks for posting the link. i have come across a lot of praise (on this forum)for the volvo stern gland with others claiming to have had one in service for years well in excess of the recommended life with no leaks at all.
achwilan, you have a good point about the vibrations causing (maybe) the damage. i have fixed all but one of the engine mounts and the vibes have now stopped. my current concern is with the metal lump attached to the rubber gland and its loose fit on the shaft as i don't know whether i'll need to replace this also. Be good to hear if anyone else has this set up and how tight the metal 'bearing' is on the shaft.

 

[thalassa]

In normal practice, the Volvo stern gland is pushed directly on the stern tube. I can only guess that the original setup had a stuffing box, and that the previous owner, when exchanging it for a Volvo rubber gland, wanted a similar distance from the tube end, or position on the propshaft. Maybe the propshaft suffers from some corrosion closer to the stern tube.
Double jubilee clips is the way to go with the Volvo rubber gland. They come with a SS clamp, but the local dealer here warned against using these, as the bolts can get loose from vibration.
Don't forget to grease the lips with the correct grease.

 

[pvb]

I'd go along with Thalassa's suggestion that the lump of brass was just a way of getting a more convenient position for the Volvo seal. I wouldn't worry about the play on the brass cylinder - the Volvo seal has a substantial moulded rubber section inside it, rather like a cutless bearing, which gives support to the shaft. Consequently, when the Volvo seal is attached to the brass cylinder, it's unlikely that the brass cylinder will wobble about too much.