Sail drive oil change

[Twister_Ken]

According to the service book, my saildrive is due an oil change, which means a lift-out. However, the oil is up to level, and is still clean and golden to look at. Does it actually require changing at this point, or is it just the manufacturer (Yanmar) covering its backside?

(Oil last changed May 2015, hours since then approx 250)

 

[prv]

If you do need to change it, can you not suck it out with a Pela? That's what I do with our Volvo. Seems bonkers that you'd need to lift the whole boat out just to change the gearbox oil.

As for whether it's necessary, my suspicion is that it isn't, but I don't really have any evidence for that.

Pete

 

[RichardS]

Yes, it's just manufacturer BS. As long as it's not gone coffee coloured (mine has ) the seals are fine and the oil is fine.

I'm going to change mine to EP (hypoid) next time which I won't change until the seals go again but even non EP will last for years and I would expect that the seals will go first.

Think about car diffs and gearboxes - much higher stress than boats and many, like mine, are now sealed for life.

Richard

 

[VicS]

According to the service book, my saildrive is due an oil change, which means a lift-out. However, the oil is up to level, and is still clean and golden to look at. Does it actually require changing at this point, or is it just the manufacturer (Yanmar) covering its backside?

(Oil last changed May 2015, hours since then approx 250)

The danger is that water could get into the lower part due to damaged/ defective prop shaft seals.

How bad would water intrusion into the lower part have to be before any signs were seen in the oil in the upper part and how long would it take ?

The only way you can be sure all is well is to drain the oil from the bottom ... having said that some ( later) VP drives have the facility to change just the oil in the upper gear box. That seems to me to be pretty close to pointless.

 

[Skylark]

If the change is required by the service routine, why not do it? If Yanmar thinks it's necessary, I'd prefer to heed their advice than take it from other, less informed, armchair experts.

It's little cost for peace of mind. It is easy with the leg out of the water but it can also be done while afloat. The manual (mine is SD40) shows both options. Mine recommends only Quicksilver HP gear oil which costs an eye watering £20 per litre (I bought 50 litres of engine oil and 10 litres of Quicksilver last year, quite a saving). My engine will have only done about 20 hours in the last 12 months but I'll still change lubricants and filters. It's no big cost and doing it provides a good opportunity to give it a good look over, grease linkages and check the electrickery.

 

[mdonnelly]

How bad would water intrusion into the lower part have to be before any signs were seen in the oil in the upper part and how long would it take ?
About 1 week! Several years ago got a new engine and sail drive. Seals on sail drive turned out to be faulty and sail drive was replaced. After lifting out and changing oil the oil was emulsified due to water ingress within a week.

 

[maby]

You certainly can change the oil in a Yanmar saildrive while afloat, but Yanmar recommend that you should not do it several times running because you don't drain it completely. I don't think sucking it out with an engine oil change pump would be very successful - the correct sail drive oil is very thick. I believe the Yanmar recommendation is to blow it out - there are two plugs at the top of the drive and you remove them both - you connect a drain pipe to one opening and a compressor to the other and pump up the pressure - the channel runs from one plug down the leg and back up to the other plug as I understand it.

 

[maby]

How bad would water intrusion into the lower part have to be before any signs were seen in the oil in the upper part and how long would it take ?
About 1 week! Several years ago got a new engine and sail drive. Seals on sail drive turned out to be faulty and sail drive was replaced. After lifting out and changing oil the oil was emulsified due to water ingress within a week.

That's the point of the Quicksilver oil at its ridiculous price! It is supposed to cope better then ordinary gear oil with water ingress

 

[RichardS]

That's the point of the Quicksilver oil at its ridiculous price! It is supposed to cope better then ordinary gear oil with water ingress

Although neither Yanmar nor Volvo manufacture their own oils so the expensive bottles are just re-badged cheaper stuff.

The High Pressure classification is another term for Extreme Pressure as specified for hypoid gears (taper faced) in many car diffs and gearboxes. I think Valvoline use the term HP rather than EP so I would bet that the Quicksilver stuff is Valvoline manufacture and you could use that instead.

EP/HP is more expensive than the equivalent straight-cut gear oil but it is higher duty and can equally-well be used for non-EP applications although might be considered overkill. I'm going to start using it rather than the plain because I can then just store one kind of oil for boat (SD20 saildrive and windlass) and various cars. If I'm not changing the oil very often I would prefer to use the best stuff!

Richard

 

[maby]

Although neither Yanmar nor Volvo manufacture their own oils so the expensive bottles are just re-badged cheaper stuff.

The High Pressure classification is another term for Extreme Pressure as specified for hypoid gears (taper faced) in many car diffs and gearboxes. I think Valvoline use the term HP rather than EP so I would bet that the Quicksilver stuff is Valvoline manufacture and you could use that instead.

EP/HP is more expensive than the equivalent straight-cut gear oil but it is higher duty and can equally-well be used for non-EP applications although might be considered overkill. I'm going to start using it rather than the plain because I can then just store one kind of oil for boat (SD20 saildrive and windlass) and various cars. If I'm not changing the oil very often I would prefer to use the best stuff!

Richard

I thought the claim was that the Quicksilver stuff was EP oil with additives that helped reduce the impact of water contamination

 

[RichardS]

I thought the claim was that the Quicksilver stuff was EP oil with additives that helped reduce the impact of water contamination

All modern API gear oils contain the water emulsification additives for applications like my Son's 4WD where the differentials have breathers which can be below water level when he is crossing rivers whilst off-roading.

Richard

 

[Yngmar]

How bad would water intrusion into the lower part have to be before any signs were seen in the oil in the upper part and how long would it take ?

Not long! Motor for 20 minutes at cruising speed, stop the engine, take a look at the dipstick (Volvo here, but I assume Yanmars have a dipstick on top of the gearbox too). If it is foamy (ATF) or milky (oil), you've got some water in. However, that's only the second best indicator. The best indicator is a light hiss when you unscrew the dipstick, as the intruding water builds up a little bit of pressure inside (so don't keep checking it after you find signs of a failed seal - the lubricant keeps most of the water out if you keep it shut).

On the upside, I've done quite a bit of motoring on the transit from Plymouth to Brighton before replacing the spent shaft seals, and things were absolutely fine upon taking it apart (and there was very little water in the lubricant, despite foam on the dipstick).

As for replacing it, oil change pump may or may not work depending on the design (in mine, you would never get the hose down into the leg so can't get even half of it out that way). If the lubricant is clear moments after motoring, don't bother unless it's for the warranty/insurance (in which case they probably demand "professional" servicing anyways). Also, drying out may be an option, as it's usually a quick and trouble-free procedure (just hang a bucket from the prop to catch the oil). Do have a spare oil screw and o-ring on board just in case.

 

[prv]

As for replacing it, oil change pump may or may not work depending on the design (in mine, you would never get the hose down into the leg so can't get even half of it out that way).

Mm. Mine (Volvo) has a fitting on top to plug into, which I assume connects either to a pipe running down alongside the driveshaft, or a channel machined in the casing to do the same job. I can see that if you didn't have that, sucking out the oil would be difficult or impossible.

Pete

 

[Yngmar]

Mm. Mine (Volvo) has a fitting on top to plug into, which I assume connects either to a pipe running down alongside the driveshaft, or a channel machined in the casing to do the same job. I can see that if you didn't have that, sucking out the oil would be difficult or impossible.

Pete

I believe that's the case from the 130S onwards. On my 120S-E you can't get the hose down into the leg because you'd have to make several turns and thread through the connector plate between the gearbox and the leg.

 

[duncan99210]

On the Volvo 120SE saildrive, you can wiggle the thin pipe from a Pela pump down to the bottom of the leg and suck out about 95% of the oil. Takes time to come out as it's fairly thick but it does come out. No idea if it's possible to pull the same trick with other drives but it works for me. Note that it takes a bit of doing to get the pipe right down to the bottom of the leg, you need to twist it at some points to get it to follow the right path.

 

[Daydream believer]

Points worth noting:-

1)Water in the oil will damage the cintered clutch plates - According to Volspec

2)When replacing the plug always use a new washer of the correct size & type
I damaged my washer so in my ignorance I used a copper one. As a result I soon had water ingress & had to have the boat lifted in Cherbourg. I had thought it was the seals & did arrange for the French Volvo dealer to change them. However, they are such a disorganised bunch of muppets I followed Volspec's advice & just changed the washer & that solved the problem. ( Thanks for excellent advice Volspec)

 

[savageseadog]

If the change is required by the service routine, why not do it? If Yanmar thinks it's necessary, I'd prefer to heed their advice than take it from other, less informed, armchair experts.

There's one good reason for not changing the oil. It;s not unknown for people to make a cods of it with leaking/stripped plugs, wrong oil etc. Unless there's water in the drive, leave alone.

 

[nigelmercier]

On the Volvo 120SE saildrive, you can wiggle the thin pipe from a Pela pump down to the bottom of the leg and suck out about 95% of the oil...

What size is this thin pipe?
Is this through the dipstick hole, or the filler?

 

[duncan99210]

What size is this thin pipe?
Is this through the dipstick hole, or the filler?

Nigel,
No idea as to the actual size of the pipe but the Pela pump comes with two pipes that you connect to the large one that plugs into the top of the pump. I used the smaller of the two.
It goes down through the dipstick hole. You will encounter a blockage after you've inserted about 50 cm of pipe, if you twist the pipe whilst still keeping a gentle downwards push in it, you'll suddenly find it goes in another 50cm or so. Don't push too hard on the pipe as you wiggle it past the half way point or all you'll do is push it up the other side of the leg rather than down to the bottom.
I know I got nearly all the oil out of the leg by measuring how much I extracted: it was about 95% of the nominal capacity of the leg.

 

[wizard]

Nigel,
No idea as to the actual size of the pipe but the Pela pump comes with two pipes that you connect to the large one that plugs into the top of the pump. I used the smaller of the two.
It goes down through the dipstick hole. You will encounter a blockage after you've inserted about 50 cm of pipe, if you twist the pipe whilst still keeping a gentle downwards push in it, you'll suddenly find it goes in another 50cm or so. Don't push too hard on the pipe as you wiggle it past the half way point or all you'll do is push it up the other side of the leg rather than down to the bottom.
I know I got nearly all the oil out of the leg by measuring how much I extracted: it was about 95% of the nominal capacity of the leg.

Thanks for the info that is a really useful tip.