Caladh
Well-Known Member
One of these is fitted to my "new" boat. What sort of oil should I use to top it up ?
Oil fed stern gland
- Thread starter Caladh
- Start date
rob2
Well-Known Member
I have an oil fed gland on my "old" boat. It has a reservoir which looks very like an old-style mini's clutch reservoir. The smell of the content indicate it is ATF - though I'm not sure what particular properties that has to suit this application. As it is fed to the space between two lip seals, I can only imagine that it is there purely to lubricate the lips and any loss of oil would indicate a need to refurbish the assembly!
Rob.
Rob.
James_Calvert
Well-Known Member
Years ago I was told Hypoid 90.
But the last time I topped up the system after some work on it I inadvertently used cheapo engine oil.
No problem since.
I wouldn't add either to ATF though!
But the last time I topped up the system after some work on it I inadvertently used cheapo engine oil.
No problem since.
I wouldn't add either to ATF though!
PowerSlapper
Well-Known Member
Light (low viscosity) machine oil or 3:1. oil is there to lubricate the bronze bush/bearing (which runs on the prop shaft) within the seal carrier and also lubricate the forward seal and middle seal. The rear seal is sea water lubricated.
If changing seals be careful to fit the the correct way round.
Front seal (inboard) lip facing stern
Middle seal (fitted from rear of unit) lip facing forward,
Rear seal (outboard) lip facing astern something like this arrangement: <-stern ][ bush ] forward->
If changing seals be careful to fit the the correct way round.
Front seal (inboard) lip facing stern
Middle seal (fitted from rear of unit) lip facing forward,
Rear seal (outboard) lip facing astern something like this arrangement: <-stern ][ bush ] forward->
pvb
Well-Known Member
I had a Halyard seal on my old boat; Halyard specified ordinary engine oil.
PowerSlapper
Well-Known Member
Quite correct, however I found the viscosity to be
too high to allow the oil to flow to the seal under gravity (perhaps the feed tube was too narrow at ¼" bore) hence the use of a light machine oil.
vyv_cox
Well-Known Member
There are a couple of pics of Halyard seals on the website at https://coxengineering.sharepoint.com/Pages/Sternglands.aspx The oil does not seem very critical - engine oil perfectly OK. Although the link says ATF can be used, I have some doubts as to its necessity, as this heavily loaded oil is normally used where a lot of friction, or a lot of steel on steel, is expected. In the case of a Halyard there is neither.
I have some pics of a Halyard seal being serviced and tested, ready to go on the website. I am holding back until the new site is up and running. I could mail them to you if you PM me your address.
I have some pics of a Halyard seal being serviced and tested, ready to go on the website. I am holding back until the new site is up and running. I could mail them to you if you PM me your address.
Caladh
Well-Known Member
Ok thanks for your replies - I am unsure as to how to ascertain the "make" but the boat is a Malo
seaangler23
Well-Known Member
I have a bukh version which is essentially 3 crankshaft oil style seals and engine oil is all that's been used in it, not a fan personally as there is not much tolerance for wear or any contingency fix if they let go.
James_Calvert
Well-Known Member
Whilst an unattended leak would eventually sink the boat I understand that the gland will be reasonably happy just water lubricated if all the seals fail. Just need to keep it cool.
vyv_cox
Well-Known Member
The 'beauty' of lip seals is that they almost never 'let go' totally. As the tip of the lip wears it will slowly begin to weep fluid, giving plenty of warning of failure. Even when in a very worn state the amount of water getting into the boat should be manageable for a long time.
Caladh
Well-Known Member
Well that's comforting Vyv !
vyv_cox
Well-Known Member
There have been many versions of this type of seal. Albin Ballads have their own, I know of a BMW one and of course there is the Bukh one that I believe is a direct copy of another make. Their advantage is that they all use automotive type seals that are readily available almost anywhere at low cost. The Halyard is rather more complicated, which makes it larger, but they mostly seem to work well at the price of more kit and complexity compared with other later designs. Hence Halyard no longer support theirs but of course the lip seals are always available.
rob2
Well-Known Member
Exactly, a old style lip seal type can be refurbished as many times as required - probably outliving the boat - the only expensive replacement will be the propshaft when the bearing area becomes worn, although it may be possible to alter the length of the hose to engage on a fresh section of the shaft. One word of caution is to ensure the replacement seals have stainless springs!
As I am about to refurbish mine, I was thinking about how to slide the new seals onto the shaft without tearing their tips. At the moment, I'm toying with the idea of wrapping the shaft in Tyvek during the fitting, which should pull out quite easily after assembly - or maybe a new, plastic £5 note? I also have a vague memory of thin stainless shims which can be slid onto a shaft to create a new seal surface. Anyone remember the name?
Rob.
As I am about to refurbish mine, I was thinking about how to slide the new seals onto the shaft without tearing their tips. At the moment, I'm toying with the idea of wrapping the shaft in Tyvek during the fitting, which should pull out quite easily after assembly - or maybe a new, plastic £5 note? I also have a vague memory of thin stainless shims which can be slid onto a shaft to create a new seal surface. Anyone remember the name?
Rob.
pvb
Well-Known Member
SKF Speedi Sleeve.
vyv_cox
Well-Known Member
Simply Bearings also supply a different version - Sturdi seal https://simplybearings.co.uk/shop/Products-Speedi+Sleeves/c4747_5335/index.html
reeac
Well-Known Member
My understanding is that ATF is a gear oil with added anti-foaming and anti- oxydising additives but I can't see those being relevant to a stern gland. I would support the use of cheap engine oil, choosing a viscosity which results in a small but detectable useage rate
vyv_cox
Well-Known Member
The additive packages for ATFs are perhaps the most sophisticated to be found in any lubricants. They may contain up to 20 different additives. A bit over the top for a very simple rubber-on-metal seal.
Wiki says: Modern ATF typically contains a wide variety of chemical compounds intended to provide the required properties of a particular ATF specification. Most ATFs contain some combination of additives that improve lubricating qualities, such as anti-wear additives, rust and corrosion inhibitors, detergents, dispersants and surfactants (which protect and clean metal surfaces); kinematic viscosity and viscosity index improvers and modifiers, seal swell additives and agents (which extend the rotational speed range and temperature range of the additives' application); anti-foam additives and anti-oxidation compounds to inhibit oxidation and "boil-off"(which extends the life of the additives' application); cold-flow improvers, high-temperature thickeners, gasket conditioners, pour point depressant and petroleum dye. All ATFs contain friction modifiers, except for those ATFs for certain manufacturer specifications.
https://en.wikipedia.org/wiki/Automatic_transmission_fluid
Tranona
Well-Known Member
Vetus still offer a range of dual lip seal shaft seals, including one type that is in a solid tube for welding into steel boats, no doubt reflecting the demands of the Dutch boat building industry.
winsbury
Well-Known Member
Bukh recommend SAE 90 for theirs. Replacement marine quality seals are cheap and repair is relatively quick and easy. There are a variety of methods of repairing the shaft if it is excessively worn at the mating face including skimming, shimming and specialist metal epoxies although a new shaft is probably a lot less bother and avoids having to use non-standard seals.