MS2B oil cooler - Do I need it?

[smb]

I suspect that the oil cooler on my gearbox has failed. Symptoms include:-
An unexplained wetness around and under the box,
Fresh oil quickly becoming thin and dirty
An upsurge of creamy oil on removing the filler cap when engine running.

This latter, whilst perhaps the clincher, I was not been able to repeat during the limited time I had to investigate. As the flow and return are adjacent to each other on the pipe between heat exchanger and exhaust elbow I am not sure how much cooling flow there is and how it is maintained.

Assuming the parts are available replacement of the cooler does not look too difficult. As I understand it, the only 'setting' is achieved when the shaft nut is tightened to the correct torque as determined by preload. If the gearbox is the source of oily deposits in the bilge its also likely some seals will be compromised, unless there is a vent/breather that I have not found.

My query really revolves around does the gearbox actually need a cooler? Sure Mr VP fitted one, but then he also expected the gearbox outbut bearings to withstand prop thrust and in my installation that is taken care of by an Aquadrive setup so to my thinking the primary source of load/friction/heat has been removed.

Having just launched I'd prefer to spend my time sailing rather than spannering and I'm thinking of bypassing the cooling circuit, do a few cleansing oil changes and postpone the surgery until the autumn or beyond.

Any thoughts?

Steve

 

[RichardS]

I would be very surprised if an oil cooler is an essential fitment in the UK.

You might be able to easily bypass the cooler and stick a cheap temp probe on the pipe to see whether it stays in the temp range specified by Volvo.

Richard

 

[Bilgediver]

It seems that some of these gearboxes had connections at the lower rear which could be utilized for oil cooling. Circulation was induced by the rotation of the drive crown wheel so minimal. If removing the cooler then these connections must be plugged. You do not say what engine this cooler is fitted? I would suspect that the cooler is doing very little and it would be worth trying to run without it. The cooler is probably a standard Volvo cylindrical cooler and that green paint makes it very expensive. If there is oil appearing at the drive flange then this indicates that the output shaft seal needs to be replaced. As you say the Aqua drive will reduce the load on the gearbox thrust bearing so the gearbox may well run cool without the oil cooler.

You must flush out all remnants of that creamy emulsified oil.

 

[VicS]

I suspect that the oil cooler on my gearbox has failed. Symptoms include:-
An unexplained wetness around and under the box,
Fresh oil quickly becoming thin and dirty
An upsurge of creamy oil on removing the filler cap when engine running.


My query really revolves around does the gearbox actually need a cooler?
Any thoughts?

Steve

The symptoms seem pretty conclusive !

IIRC you have a fairly large engine, 65 hp MD30A ???? If so your gearbox ix transmitting quite a bit of power. While the oil cooler may not be essential when fitted to small, 10 or 20 hp engines the MD30 may be a different matter

I believe the original oil cooler is obsolete but that there is a replacement at €158.

With smaller engines all the incoming engine cooling water flows through the cooler. Yours appears to be plumbed differently.

I would be very surprised if an oil cooler is an essential fitment in the UK.

You might be able to easily bypass the cooler and stick a cheap temp probe on the pipe to see whether it stays in the temp range specified by Volvo.

Richard

Not sure quite what you mean by bypassing the cooler and sticking a temp probe in the pipe.
Have you seen a specified temperature range ?

It seems that some of these gearboxes had connections at the lower rear which could be utilized for oil cooling. Circulation was induced by the rotation of the drive crown wheel so minimal. If removing the cooler then these connections must be plugged. You do not say what engine this cooler is fitted? I would suspect that the cooler is doing very little and it would be worth trying to run without it. The cooler is probably a standard Volvo cylindrical cooler and that green paint makes it very expensive. If there is oil appearing at the drive flange then this indicates that the output shaft seal needs to be replaced. As you say the Aqua drive will reduce the load on the gearbox thrust bearing so the gearbox may well run cool without the oil cooler.

You must flush out all remnants of that creamy emulsified oil.

Surely the cooler is inside the rear bearing housing. I believe the attached picture, snipped from the WS manual, shows it. Not exactly a standard Volvo cylindrical cooler!

 

[Bilgediver]

The symptoms seem pretty conclusive !

IIRC you have a fairly large engine, 65 hp MD30A ???? If so your gearbox ix transmitting quite a bit of power. While the oil cooler may not be essential when fitted to small, 10 or 20 hp engines the MD30 may be a different matter

I believe the original oil cooler is obsolete but that there is a replacement at €158.

With smaller engines all the incoming engine cooling water flows through the cooler. Yours may be plumbed differently.




Not sure quite what you mean by bypassing the cooler and sticking a temp probe in the pipe.
Have you seen a specified temperature range ?




Surely the cooler is inside the rear bearing housing. I believe the attached picture, snipped from the WS manual, shows it. Not exactly a standard Volvo cylindrical cooler!

View attachment 70505

That was the the earlier gearboxes.

 

[RichardS]

Not sure quite what you mean by bypassing the cooler and sticking a temp probe in the pipe.
Have you seen a specified temperature range ?

Bypass it/blank it off/whatever he intended to do to remove it .... depending on the design, then stick the £2 thermocouple wherever it can best monitor the temperature. It's not rocket science.

https://www.ebay.co.uk/itm/Digital-...hash=item2cb2ccb379:m:mThD-4leyRa2cpEmIQmbXjA

As far as the correct temp range goes, the OP could call VP if her can't find the approved range, or just adopt common practice of a maximum gearbox oil temp of around 80 degree max after sustained high speed running. If normal usage registers anything up to 50 degrees then I'd be happy.

Richard

 

[smb]

Thanks for all the input here.
The engine is indeed an MD30, supposedley capable in 1986 of 65hp at 3800 rpm. However, the passage of time and the fact that we never need to exceed c2500 rpm and cruise at approx 1700 would suggest a more likely output in real life of perhaps 35-40hp max.

Judging by the fittings on the outside of the gearbox I believe the oil cooler to be as per the snippet of the ws manual Vics supplied. I have found a part no 852163 which does seem to be available around the e160 mark, which seems to be a bit steep for a short copper horseshoe but no real surprise knowing the make.

In the short term I will try running without the gearbox oil cooler and monitor its temperature over a trial run. I'm expecting it will, by conduction if nothing else, reach the same temp as the engine its bolted too. Vics may remember from previous posts that that never gets hot enough to trouble the thermostats as it has a full flow engine oil cooler of the more typical 'tubestack' arrangement that sucks a lot of the heat away. Again, a requirement of what the engine was designed to do rather than what it actually does.

I dont understand what drives the seawater around the gearbox cooler circuit as the flow and return are two spigots one behind the other off the feed pipe to the exhaust elbow. I have a theory that there may be some internal arrangement that provides a venturi effect, however in the interest of continuity when I disconnect the pipes to the gearbox I will connect the spigots with a couple of elbows and some heater hose. The feed pipes themselves will be drained but left in situ to stop any oil seepage. Their open ends will extend a long way above the gearbox oil level.

If the following link works much will be explained.

https://www.dropbox.com/s/wftmhp9zx9m7tus/md30 brochure.pdf?dl=0



Steve

 

[VicS]

I dont understand what drives the seawater around the gearbox cooler circuit as the flow and return are two spigots one behind the other off the feed pipe to the exhaust elbow. I have a theory that there may be some internal arrangement that provides a venturi effect, however in the interest of continuity when I disconnect the pipes to the gearbox I will connect the spigots with a couple of elbows and some heater hose. The feed pipes themselves will be drained but left in situ to stop any oil seepage. Their open ends will extend a long way above the gearbox oil level.

If the following link works much will be explained.

https://www.dropbox.com/s/wftmhp9zx9m7tus/md30 brochure.pdf?dl=0



Steve

Likewise puzzled by the connections

Some good pictures in the link which explain the arrangement in the gearbox

 

[scottie]

Is the water flow not determined by the suction from the seawater pump
Removing the horseshoe pipe from the system should be a simple matter of joining The inlet and outlet hoses if it were not leaking you would not even have to cap the cooler ends

 

[Bilgediver]

Thanks for all the input here.
The engine is indeed an MD30, supposedley capable in 1986 of 65hp at 3800 rpm. However, the passage of time and the fact that we never need to exceed c2500 rpm and cruise at approx 1700 would suggest a more likely output in real life of perhaps 35-40hp max.

Judging by the fittings on the outside of the gearbox I believe the oil cooler to be as per the snippet of the ws manual Vics supplied. I have found a part no 852163 which does seem to be available around the e160 mark, which seems to be a bit steep for a short copper horseshoe but no real surprise knowing the make.

In the short term I will try running without the gearbox oil cooler and monitor its temperature over a trial run. I'm expecting it will, by conduction if nothing else, reach the same temp as the engine its bolted too. Vics may remember from previous posts that that never gets hot enough to trouble the thermostats as it has a full flow engine oil cooler of the more typical 'tubestack' arrangement that sucks a lot of the heat away. Again, a requirement of what the engine was designed to do rather than what it actually does.

I dont understand what drives the seawater around the gearbox cooler circuit as the flow and return are two spigots one behind the other off the feed pipe to the exhaust elbow. I have a theory that there may be some internal arrangement that provides a venturi effect, however in the interest of continuity when I disconnect the pipes to the gearbox I will connect the spigots with a couple of elbows and some heater hose. The feed pipes themselves will be drained but left in situ to stop any oil seepage. Their open ends will extend a long way above the gearbox oil level.

If the following link works much will be explained.

https://www.dropbox.com/s/wftmhp9zx9m7tus/md30 brochure.pdf?dl=0



Steve

I am now puzzled as the picture I am seeing DOES NOT show an oil cooler but shows sea water being fed to the thrust bearing housing. If an oil cooler is fitted then those pipes from the elbow would not go direct to the gearbox but to the cooler and then there would be another set of pipes to the gearbox which would not be connected to the thrust housing as here but to connections on the actual gearbox housing .

 

[VicS]

I am now puzzled as the picture I am seeing DOES NOT show an oil cooler but shows sea water being fed to the thrust bearing housing. If an oil cooler is fitted then those pipes from the elbow would not go direct to the gearbox but to the cooler and then there would be another set of pipes to the gearbox which would not be connected to the thrust housing as here but to connections on the actual gearbox housing .

They connect to the horseshoe shaped cooling element that I posted a picture of earlier

If you go towards the end of the link smb posted you will find a couple of other pictures that help to clarify the arrangement and here a pipcture of the oil cooler element itself

I have not come across any indication that MS2B gearboxes are connected to external oil coolers, although it would not be impossible to do if the internal cooler is removed and oil flow and return pipes connected in place of the water pipes. The oil flow through such a cooler would not be great, if at all, though.

Some other similar gear boxes do appear to have provision to connect external oil coolers

 

[smb]

Is the water flow not determined by the suction from the seawater pump
Removing the horseshoe pipe from the system should be a simple matter of joining The inlet and outlet hoses if it were not leaking you would not even have to cap the cooler ends

For sure the total flow in the system is down to the seawater pump efficiency, however the curious (though unimportant) part is how some of that water gets to flow through the gearbox coil when both the feed and return are side by side on the same pipe.

Guess I’m looking at around the e200 mark once I’ve thrown in a few seals and a preload spacer so i may well restore to full spec in the autumn. I’m just a bit reluctant to tackle it now if it’s not essential as it seems everything I currently lay my hand to turns to rat poo in short order, up to and including my trusty Suffolk Punch this very day.

Apologies if my describing the potential faulty part as an oil cooler led to visions of tranny oil being pumped to an external heat exchanger, I see now I could of been more specific.

Steve

 

[Heckler]

For sure the total flow in the system is down to the seawater pump efficiency, however the curious (though unimportant) part is how some of that water gets to flow through the gearbox coil when both the feed and return are side by side on the same pipe.

Guess I’m looking at around the e200 mark once I’ve thrown in a few seals and a preload spacer so i may well restore to full spec in the autumn. I’m just a bit reluctant to tackle it now if it’s not essential as it seems everything I currently lay my hand to turns to rat poo in short order, up to and including my trusty Suffolk Punch this very day.

Apologies if my describing the potential faulty part as an oil cooler led to visions of tranny oil being pumped to an external heat exchanger, I see now I could of been more specific.

Steve

On my MS2 box the cooling sea water is sucked through that cooler by the raw water pump. It is a basic pipe routed through the box with a couple of 6mm bolts holding a plate that has a rubber seal sealing a flanged copper pipe to the cooler. So the cooler is under negative pressure in mine. I have no reason to see why others arent the same. I have always said that if mine goes tits up that I would bypass it . The only issue could be oil dripping out of the flanges if the internal pipe is comprimised but it would be easy to blank those connections off. The amount of continuous hp we actually use is far less than what the engine is rated at and the heat produced in uk waters would I think be not likely to cause issues. I would join the two pioes together and make sure that there isnt any leaks from the by passed cooling bit

 

[rickywright78]

Sorry to resurrect this thread but I have the same issue - creamy oil in my MS2 gearbox... I've a Volvo Penta MD2010 - so only 10hp... I'm keen to hear from @smb Steve if bypassing the oil cooler caused any issues of overheating etc & if he would recommend it? Anyone else have any experience of this? Cheers, Ricky

 

[Swampyhotdog]

Hi folks,

Just wondering if anyone has tried running the MS2B gearbox without the cooling hooked up? I've just discovered that one of the copper pipes is corroded through, they are now obsolete, and anyone selling them wants a fortune!

Ive got a 36 foot yacht with VP2003 engine (28HP) and the aforementioned MS2B box, cruising Irish waters.

Since I've got the engine out now, I'm going to treat the box to new seals, and wouldn't like to cook them on the first trip.

Has anyone tried this?

Cheers
Stu

 

[Dantp]

Hi Stu
If you need the inlet and outlet pipes for the gearbox then try your plumbing store for an elbow with a flared end and BSP fitting.
Carefully cut off the nut and there you go a few pence.
We found one suitably sizes in france, not sure if they use slightly different sized copper pipe. It's still going 4 years later.
A plumber may be able to make you one as well.
It would be nice to know though if the gearbox didn't need cooling.

Dan

 

[matuca]

Sorry to resurrect this thread but I have the same issue - creamy oil in my MS2 gearbox... I've a Volvo Penta MD2010 - so only 10hp... I'm keen to hear from @smb Steve if bypassing the oil cooler caused any issues of overheating etc & if he would recommend it? Anyone else have any experience of this? Cheers, Ricky

Hi Ricky! I have the same engine MD 2010 in my Ericson 27 feet with the gearbox MS2A seawater inlet/outlet pipe corrosion and leakage issues. This is my first boat and I had no experience at all before, so it took me long hours of reading to identify the issue. There was not enough seawater flow coming throuth the exhasut so I did a step diagram of the seawater flow system to identify the issue:

1) Seawater skin fitting intake
2) Gearbox seawater inlet/outlet
3) Pump/impeller inlet/outlet
4) Heat exchanger inlet/outlet
5) Elbow and exhaust system outlet

After removing all the hoses I discovered that there was no seawater flow pressure coming from the gearbox seawater cooling outlet pipe. With so reduced engine hatch space, it was impossible to access the gearbox inlet/outlet pipes to fix them, I was only able to touch the pipe connectors and check that they were corroded, probably with a bad mix of leakage and interior blockage, I unsuccessfully tried to use Silka to stop the leak.

Removing the engine was not an option for me at that moment, so yesterday I decided to bypass the gearbox seawater cooling system and connect the sewater intake hose directly to the pump/impeller inlet, surprisingly the amount of seawater coming throught the exhaust is better than ever, looks like the heat exchanger and the rest of the main seawater cooling system is working fine!!

Without a sewater cooling system in the gearbox, I need to start monitoring that the gearbox oil does not overheat after long engine runs. It is not the best solution, but is the only one I can afford at the moment, without having to remove the engine and disamble the gearbox. I will let you know in a few weeks if the ingine is cooked or not.

With a "working" engine again, I can go sailing again that is the main reason of all this endless project

Defintely the next maintenace task will be removing the rust and corrossion from the shaft coupling and gearbox flange with a wire brush and angle grinder and see if I can save them or they need to be replaced (see picture)

Cheers!
Matias