Water in saildrive oil - how worried should I be?

[ThereAndBack]

Hi everyone

I am just about to buy my first yacht, a Bavaria 37 (2001) with the 28 Kw Volvo engine. My surveyor found that one of the anode screws on the saildrive had worked loose and worn away a little of the anode and a little of the rear of the prop (the screw was hanging between the them - see photo).

He also found traces of water in the saildrive oil.
He was concerned that the screw may have caused the shaft (that the prop is attached to) to have run out of true and allowed the water in.

The local marine engineering company (who fitted the anode) say that a small amount of water in the saildrive oil is quite common as it will be the original (5+ years old) oil. They are going to 'have a look at it' but do not expect to find any problems.

Any advice will be most welcome.

 

[steve6367]

I am no expert on sail drives - but water in there should be regarded as "normal". I would change the oil once a year to check for water though so maybe I just worry too much. Worth asking Volvo?

 

[AIDY]

It's not uncommon for the screws to come out. in the past both of mine have disapeared and left the anode to rotate.

At a guess the water in the oil is due to wear on the two shaft seals in the saildrive. I have changed mine recently. Not a hard job to do.

Once the prop is off, and the anode you can remove the end cover from the saildrive to remove the shaft and replace the seals.

If you purchase the boat i would recommend the seal to be replaced.

These are the shaft seals, there are two back to back with grease in between. most prop worn through general use. causing small trace of water in the oil, which is not normal. Once the shaft is out you can check wear / condition of the needle bearings.

If the boats done a few miles under motor, it's a common thing.

Best of luck

 

[Wilson]

Hi

I have a Volvo 2003 with saildrive, all a little older than yours.
Had signs of water in oil when i bought her 4 years ago. While it is is not normal it is not unusual either. Mine had just started to go a milky colour but in extreme cases i was told it actually froths up through dipstick hole.

Certainly it needs the shaft seal replacing and you may well find a wear groove on shaft as mine had. Fixed this fairly simply by fitting spacer washer behind seal to move it along shaft so it sealed on a fresh surface. Alternative is the Volvo way and renew shaft at huge expense or i believe the shaft can be metal sprayed to re-instate surface. Mine has now lasted 2 seasons with no sign of further water ingress.

I would be surprised if the loose screw has damaged alignment of shaft. Shaft and bearings are very substantial. My Annode came loose and i re-fixed with loctite on screws, ensuring annode had good contact onto saildrive. Check this with ohmeter if necessary.

All told, i would say this is a typical maintenance item and not something that should put you off the boat.

Good Sailing !!!

 

[TonyS]

I cannot comment on water in the oil as in 600 hrs on my 2030 I have not found any, yet!
Regarding the loose anode, I believe it is quite common and during a lift out in May I had to replace mine. The problem seems to be that anode erosion/wear takes place between the bolt heads and the anode which removes any tension on the bolts which then become loose and may fall out. Loctite is not recommended as we require a good electrical contact but Volvo now tell their engineers to use it. I have been told, but not tried it myself, to paint Trilux over the bolt heads and immediate surrounds to stop this corrosion. I will try it next time. Hopefully next year.

 

[savageseadog]

Had a Yanmar saildrive running the last 15 years without any leaks or screws undone. Water in your saildrive isn't desirable but as long as you do something about it quickly no harm will come to it. The reason you use a marine grade gear oil is for its corrosion resisting properties.
Your prop might be out of balance due to corrosion or damage, that would give rise to vibration which may have caused some of your problems.

 

[chrisc]

When I did have a leak ,due to bad servicing on repair of saildrive in france .it was six months and 2000 Nm before I had the boat on land again and was able to change the seals on the prop end. During all this time I never got any water in the oil but had to constantly replenish the oil .Does this mean my oil level is above waterline ? If so why are others lower ? boat is Bav 34.

 

[spannerman]

As others have stated not too serious to run with a little water in the oil, the problem can occur during layup, the water can seperate out and sink to the bottom of the leg which means the bearings and gears can rust, either way I'd insist on it being fixed before I bought the boat.

 

[jackho]

For info ... I,ve had this problem on several occasions with different boats and its always been the drain plug seal. The fibre gasget needed replaced with every oil change. The newer drives have an "o" ring but I still "back up" with Teflon tape.
This just might save you some expence.

 

[John_Clarke]

I apply Volvo Penta waterproof grease to the threads and under the heads of the anode fixing screws which allows them to be tightened firmly and yet they are reasonably easy to unscrew. I do the same with the propeller cone and locking bolt. After 7 months they are always firm and this has been my experience for the 6 layups I have done on the boat

 

[ThereAndBack]

Thank you, everyone, for the very useful info and suggestions.

At least, this seems nothing to be worried about - so the purchase can go ahead.

Again, thanks.

 

[AIDY]

Best of luck with you new toy..