Gearbox oil appearance

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Newman

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Morning all

Finally got my new (secondhand) 1990 Bavaria 300 'back to base' which meant I had to motor for appx 4 hours. Had a quick check before leaving the boat and among other things looked at the gearbox oil level. The oil on the dipstick appeared to be something like a weak 'mayonnaise' mixture.

The engine is a Volvo Penta 2002 18HP and the gearbox uses the same oil as the engine.

Can you wise and experienced people out there please inform this novice as to probable causes and remedies ?.

I would also be very interested to recieve suggestions on a "happy running rpm level" for such an engine, taking in to account it's age, unknown usage and unknown service history. Someone more experienced who was on board for part of the journey remarked on how quiet the engine was running at 2000 rpm.

As usual I will be grateful for all responses

Many thanks
 
dont be too hasty, many manufactures advise against checking the oil after the gearbox has been run because it airates and gives the appearance of being contaminated with water. Let it alone for a day and check it again, if it has cleared than no problem, if its still "white" change it anf try to find out where the water is comming from - the oil cooler is the first port of call.
 
Definitely water in the oil. Several possible causes: most likely water pump drive shaft seal leaking. next most likely leaking head gasket, third cracked block, fourth (unlikely) severe condensation, fifth contaminated oil at last oil change.

As suggested, immediate oil change, and monitor carefully.
 
Newman said:
Morning all

Finally got my new (secondhand) 1990 Bavaria 300 'back to base' which meant I had to motor for appx 4 hours. Had a quick check before leaving the boat and among other things looked at the gearbox oil level. The oil on the dipstick appeared to be something like a weak 'mayonnaise' mixture.
Click to expand...

This is an odd one as I believe this gearbox is not water cooled like the earlier ones and so no chance of frozen passages.

Is the gearbox on top of a Saildrive????

If you have a shaft drive then it would seem the boat has had excess water in the bilges to the exten it found its way into thegear box.

You need to get all the contaminated oil out and replace with fresh. You might need to do this a couple of times to remove all the water and have clear oil.
 
I used to have a boat with a VP2001 which iirc uses the same gearbox, and i seem to recall the gearbox is watercooled,
before resorting to major surgery could a leak from this area be ruled out?

Volvo penta have a website where you can download obsolete workshop manuals for your engine.

Oops didnt see your post above.
 
Gearbox has a separate oil supply and there is a form of oil cooler in that there is a copper pipe in horse shoe form in the reaction gear you will see the water connections
The oil pipe is subject to frost if not drained or left with antifreeze.
 
Marsupial said:
dont be too hasty, many manufactures advise against checking the oil after the gearbox has been run because it airates and gives the appearance of being contaminated with water. Let it alone for a day and check it again, if it has cleared than no problem, if its still "white" change it anf try to find out where the water is comming from - the oil cooler is the first port of call.
Click to expand...

Water in the engine oil is the more common occurrence I think. Any number of causes from gaskit to water pump - depending on the engine. This produces a black butter residue when mixed with the products of combustion.

But the gearbox has no such access for water: an S leg's lower seals can fade and allow in seawater, producing a white smear or streaks in the oil. Such residues remain of course, whereas the aeration referred to above settles out as the oil cools. Be sure to establish you have real contamination before going in to sort it out.

PWG
 
Many thanks for all the info so far.

Perhaps I should have added that the boat has a saildrive.

It has been suggested that I buy an oil and fluid hand extractor pump on ebay to remove as much oil as poss from the gearbox. Apparently they have a long thin extractor tube which I assume is inserted into the dipstick access ?. Can anyone advise if this is the correct method and how much oil I can expect to extract please ?

Even more thanks :)
 
Ok so now we are discussing likely water in the sail drive

It not uncommon but if not dealt with serious and expensive

The two places that you can get water in are the drain plug not being sealed ie worn seal or drain plug loose or the output shaft seals

Both require access out of the water and testing with a vacuum pump before dismantling

This may indicate leaking seals but if it the drain plug visual may be enough

You need to get the water out and flushed

If the seals are the problem you will have to check the shaft for wear it can be sleeved if required


If the hull gaiter has not been done this might be time to take the leg out to do it in work shop

I do not think that it possible to change this drives oil in place
 
Assuming your saildrive is similar to my older Volvo 120S then scottie has summarised it well. You can't remove the oil without draining it out of the bottom of the unit with the boat out of the water. It could be any of the problems he suggested. Also, the propeller shaft is prone to wear in which case the oil and water seals on the shaft fail to seal properly. The seal and shaft assembly can be removed for repair with the unit in place but out of the water. I had my seals replaced this year and the engineer carried out a pressure test on the saildrive to confirm they were working. In my case, I had taken the saildrive out of the boat.

As others have said, first confirm there is water in the oil. Vyv Cox described a crackle test to check for oil in post no 21 in this thread.
 
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