Volvo MD11C Transmission Problems

[sailingharry]

I have a new-to-me Sabre 34 with an MD11C. I changed the oil in the engine and transmission on purchase with Rotella 15-40 (no recollection of what it looked like then, unfortunately), and then checked it about 5 hours later. The tranny oil was a light brown color, like coffee with cream. Suspecting perhaps water or some other contaminant, I changed it again. 6 hours later, I looked at the oil -- same color! Now we have a problem. Again, because I suspected water, I put that second change in a glass jar, and set it in a warm spot in the house, and a week later it hasn't separated. No clear oil on top, no water on the bottom, no change at all. What's going on? Is this just entrained air from the gears? Do I have a cooler leak?

Another issue with the same tranny. I have "stuff" coming out along the shaft in the coupling. Oil, water, I'm not sure. I assume that means the rear shaft seal in the tranny needs replacing. Any thoughts or experience?

And finally, if one or the other of these items means a rebuild (I am up to the job if it is needed), where can I get an exploded view or shop manual? The Volvo manual is just for the engine. The info at marinepartseurope.com has been VERY informative, but isn't quite enough to do a rebuild!

Thanks for any input!

Harry
'79 S34-I
Annapolis

[GordMay]

The Volvo MD11 Workshop Manual is available at
➥ Index of /manuals
or
➥ Volvo Penta MD11C|D MD17C|D Diesel Engine Workshop Manual - Automobile Makes and Models Volvo - Zimbio

You can see exploded parts diagrams here
➥ Exploded views / schematics and spare parts for Volvo Penta MD11C, MD11 - MarinePartsEurope.com

Moyer Marine has an excellent tutorial on “Milky Oil” here
➥ Frequently Asked Questions: My oil has turned "milky". How can I troubleshoot to determine how much water may have gotten into my oil, and what can be done to remedy the situation?

Note the opening paragraph discussing detergent emulsification (Shell Rotella is a detergent oil).

[sailingharry]

Gord,

I already have the Volvo shop manual, and while it is moderately complete for the engine, it is pretty much silent on the tranny. I've also been to the site at MarinePartsEurope, and it was the best I'd seen to date for the Tranny. However, following your link to the Cape Dory site, I now have that same drawing in a MUCH clearer version -- THANKS! It still is lacking in any sort of discussion on how to take them apart/rebuild them, but it certainly won't be the first time I've done something like this without a manual.

The discussion on oil at Moyer is very good. Don Moyer is enough to almost make me wish I had an A-4! The detergent part of the equation was what I was missing -- the detergent will emulsify the water/oil, and keep in in suspension. I see! Thanks again!

The one part I'm missing is personal experience. Anyone have problems with these units actually leaking? Is if fixable (the drawing doesn't show a "cooler" as a replacement part -- it's part of the housing)? And do I have to pull the tranny and tear-down to replace the rear seal, or is it something that can be worked out and back in with the tranny in place?

Thanks,

Harry

[boden36]

If it is the cone type transmission you are talking about, it is easy to dismantle. You can use ATF for lubrication. Anything too slippery will cause the cones to slip.They are a pretty poor transmission. We had one on a MD 17. After several breakdowns, Volvo said they could not guarantee that it would not happen again, so we ditched the engine for a Yanmar. Best thing we ever did.Regards, Richard.

[sailingharry]

I'm not sure what a "cone" transmission is. This one is the "MSB" transmission, also called the "Reverse Gear Transmission." I'm not sure that there are any friction parts in there that would slip, but then again, the drawings are pretty unclear.

Thanks for the input.

Harry

[Paul L]

Maybe an MS8 gear? I think these take ATF, not engine oil. If you want to know what is in the fluid you remove, for a few bucks you can have a sample tested:
N C Machinery SOS Fluid Analysis

Paul L

[sailingharry]

Not an MS8. It's an MSB. Also, the manual clearly says "same oil as engine" or words to that effect. The sample test might be an interesting route to go, although I'm about 95% sure it's water and it can't come from anyplace but the oil cooler. The other 5% is my hoping that it's just left over "stuff" and one more oil change will clear it up. The oil in there is oil change #2, so I'm not very optimistic.

Harry

[boden36]

If your box is a cone type it will have a double ended male conical piece which is threaded onto a helical shaft. At either end of this shaft are fixed female cones. The idea is that when you engage the male cone with one of the female cones, the torque screws it in tightly and transmits the drive. One for fwd and one for reverse. Problems arise if you use an oil that is too slippery, or if the friction material that is bonded to the female cones wears. (early ones were just metal to metal) Also I found that the small circlip that takes the reverse thrust is too light and can pop off, leaving you with no gears at all. Regards, Richard.

[Bilgediver]

Originally Posted by sailingharry

I have a new-to-me Sabre 34 with an MD11C. I changed the oil in the engine and transmission on purchase with Rotella 15-40 (no recollection of what it looked like then, unfortunately), and then checked it about 5 hours later. The tranny oil was a light brown color, like coffee with cream. Suspecting perhaps water or some other contaminant, I changed it again. 6 hours later, I looked at the oil -- same color! Now we have a problem. Again, because I suspected water, I put that second change in a glass jar, and set it in a warm spot in the house, and a week later it hasn't separated. No clear oil on top, no water on the bottom, no change at all. What's going on? Is this just entrained air from the gears? Do I have a cooler leak?

Another issue with the same tranny. I have "stuff" coming out along the shaft in the coupling. Oil, water, I'm not sure. I assume that means the rear shaft seal in the tranny needs replacing. Any thoughts or experience?

And finally, if one or the other of these items means a rebuild (I am up to the job if it is needed), where can I get an exploded view or shop manual? The Volvo manual is just for the engine. The info at marinepartseurope.com has been VERY informative, but isn't quite enough to do a rebuild!

Thanks for any input!

Harry
'79 S34-I
Annapolis

The water in the oil could be from one of two sources. Either bilge water leaked in through the worn seal or the cooling gallery in the gearbox has cracked and se water is leaking in.

You can bypass the cooling gallery to check if this is the propblem by taking the seawater from the sea inlet direct to the sea water pump.

The oil sea can often be changed without a strip down.

Need to know which gerear box but if a seal of around 4 to 5 inches then it can be hooked out from the shaft end. I have even seen seals split with a razor saw to get them fitted without breaking the shaft coupling. This is not best. try to break out the coupling and the new shaft will go in with the help of wood and a hammer.

[azimuth]

Harry,

How did you make out with your MSB transmission issues? I have what I believe to be an identical ( or very similar) unit on a Volvo MD7A in our my 32 year old Westerly Centaur. Over the weekend it failed. Still backs up but no forward. From I have seen so far it looks like the lining on the forward cone has failed. I pulled a fragment from the inside when I removed it from the boat. I am about to tackle dismantling it but I am in the same position you were. I have service and parts manuals from a previous rebuild of the engine but no details on dismantling and reassembly of the reverse gear assembly. Did you end up disassembling your unit and if so have you any words of wisdom or further references?

Thanks

Steven

[Bilgediver]

Originally Posted by azimuth

Harry,

How did you make out with your MSB transmission issues? I have what I believe to be an identical ( or very similar) unit on a Volvo MD7A in our my 32 year old Westerly Centaur. Over the weekend it failed. Still backs up but no forward. From I have seen so far it looks like the lining on the forward cone has failed. I pulled a fragment from the inside when I removed it from the boat. I am about to tackle dismantling it but I am in the same position you were. I have service and parts manuals from a previous rebuild of the engine but no details on dismantling and reassembly of the reverse gear assembly. Did you end up disassembling your unit and if so have you any words of wisdom or further references?

Thanks

Steven

If you go to this web site then you will find your gearbox in the MD1b MD2b MD3b manual at the back. I think yours is the MS gearbox.

Sailing and Yachting Downloads Marine Engione Manuals

John

[boden36]

Steven, if you do no good with John's suggestion, I have a manual for the MS and MSB box which you can have.
The box should give good service with your engine, as they used it up to the 36hp , where it was prone to fail.
If you can get the cones relined it is much cheaper than buying new parts. Dexron ATF goes well in the box. Beware slippery oils. Regards, Richard.

[Bilgediver]

Originally Posted by Bilgediver

If you go to this web site then you will find your gearbox in the MD1b MD2b MD3b manual at the back. I think yours is the MS gearbox.

Sailing and Yachting Downloads Marine Engione Manuals

John

Please note that these gearboxes were designed for the engine oil of the period IE mineral oil for diesel engines. This might be difficult to get however we find it in supermarkets here and sold for old cars. Do not use fancy oils as this may cause the cones to slip.

Volvo cones do not normally have a lining. They are just metal cones however if the surface finish gets too highly polished they may need to be refinished. I would just use an emery tape or something. Nothing high tech.

When you find water in the volvo gearbox it is usually due to freezing damage in the cooling gallery. This fractures through to the gearbox and the crack is not visible outside. This gallery is not really necessary and many folk just take the cooling supply straight to the pump from the sea cock so bypassing the gear cooling gallery. It is worth trying this as the gear casings are obsolete.

To prevent freezing damage it is best to pump antifreeze through the engine system so filling the raw water side with antifreeze which will also get into the exhaust system. It is best to do this even if trying to drain the system as there are some parts which might not drain down such as the gearbox gallery and exhaust separator.

[azimuth]

John, Richard,

Thanks for the follow up. I got the initial info from the reference you gave, John. On that basis I did a bit more poking around and now have an MS/MSB manual from about 1975. The intro to that says that the distinguishing feature of the MSB is the lined cones on the gears. In the details it suggest that the forward gear cone can be relined but the reverse can't ?? Interestingly, the MarinePartsEurope website has pricing for everything but the those gears. I had some hope that this might be a project that I could complete in a week or two and still get a last cruise in for the season. That idea is pretty well gone now but I still have hopes that I will be able to get this done over the winter. So far I have managed to separate the reduction gear housing but I need a better puller to separate the front housing to get at the gears and really assess the problem.

Thanks again

Steven

[boden36]

Hi Steven, I have had both relined in the past. Regards, Richard.