Almanac – VP 2003 with Milky Oil in the Transmission

Image showing milky oil on the dipstick of a Volvo Penta 2003 saildrive engine
The milky oil came from the transmission gearbox of a VP 2003
Volvo Penta Owner
Volvo Penta Owner

My VP 2003 from year 1990 had visibly watered oil in the gearbox. This is the first time this happened. I can only track this to heavy rains recently or possibly driving in large waves. Since the gear oil is changed through saildrive what’s your recommendation for solving this?

The solution to this is straightforward, although it definitely requires a haul-out. Saildrives leak through the two water seals next to prop. It is fairly easy fix once the boat is on the hard.

This is actually very common for high hour saildrive engines – most saildrives will have this issue at some point in the season. Just replace the oil until it’s emulsified again, repeat until you haul out. Many owners replace the prop seals as part of their yearly maintenance.

Something as simple as tangled fishing line can cause this also. Ensuring that you put your gearbox in reverse when sailing can help prevent unnecessary wear.

Never let water contaminated oil freeze in your transmission though – this could cause cracking of the casing and be a much larger headache. Another potential problem is when debris (such as tangled fishing line) wears a groove in the prop shaft and new seals will no longer work. Then, you will need to think about re-machining the shaft and fitting a sleeve. This is best avoided by not ignoring milky gearbox oil.

And finally, be careful not to over fill the gearbox oil. This should be measured with the dipstick sitting in the hole, not screwed down. Use a piece of white handy towel for checking the level as it is sometimes hard to see – it’s not black like engine oil.

A smart skipper learns from the lessons of others.

Do you own and maintain a Volvo Penta 2000 series marine diesel engine? In our Volvo Penta 2000 Series Almanac section, we have a series of previous questions and queries from VP2000 owners along with answers. Many of these have been adapted from discussions on the “Volvo Penta Marine Diesel Engine Owners Yacht and Boat Engines” Facebook group which is a fantastic resource for getting help.

Do you want to get future VP2000 Series Almanac articles straight to your inbox? Sign up to our Volvo Penta 2000 Series Owners’ Group today and we’ll make sure that you’re first to see them. And we definitely won’t share your email address with anyone else.