twin disc mg 5050 oil change

[bligh]

Can anyone decisively tell me from this tag (see pictures) what fluid I am supposed to put in this transmission?
I already refiled it with straight 30 weight engine oil, but now I'm worried i didnt use the right fluid. I've never heard of 30 weight gear oil or 30 weight transmission oil. From the tag, I'm pretty sure I put in the right stuff- but I havent left the dock yet, so I can still pull it out of there and replace it with something else if need be.
Thanks

 

[denloe1]

Don't have my manuals handy but I recall for my twin discs they would take regular SAE 30. But Cat recommended and I used TDTO fluid from Cat.

 

[Nightcap]

You are good to go with an SAE 30 engine oil (never multigrade) unless you are operating in high seawater temps in which case an SAE 40 might be called for, depending on duty. Standard Twindisc recommendation. Remember to check oil level with engine running in neutral.

 

[dodo]

As said, regular SAE 30W is recommanded. The TwinDisc manuel only refer to the data plate on the transmission.
I use regular SAE 30W oil for my TwinDisc.

 

[Nightcap]

Yep, the important thing is to use a mongrade engine oil. In extreme water temps and high loads you would be wise to use SAE 40 but I suspect you are not in that frame so straight SAE 30 mineral based oil is the go.

 

[FF]

There is a huge difference in the oils viscosity between SAE 30 an SAE 30W !!!

IF SAE 30W is made it would be very rare .

 

[Aquabelle]

Mono 30. DON'T go to 40: the temp of the gearbox is much lower than engine temps, don't confuse the two

 

[Nightcap]

Mono 30. DON'T go to 40: the temp of the gearbox is much lower than engine temps, don't confuse the two

Gearbox temp is generally the same as engine temp as they are connected and the engine heat is transferred. SAE 40 is common for high duty commercial applications in tropical waters.

 

[bligh]

Thanks for all of the replies. I'm glad I don't have to change the oil again.

Over on the sentoa list they have been talking about transmission temperatures. There is some concern that observed operating temperatures are well below what twin discuss recommends. One of the list members was involved in transmission manufacturing and said something to the effect that there is no problem with really high transmission oil temperatures. I'll cut and paste his opinion when I am at my pic as I think you'll all find it interesting.
Anyhow, I imagine that I'll be running at below recommended temperatures. So I may have to change the oil more fequently.

 

[bligh]

As promised;
"I spent a career in the auto industry, drivetrain particularly. The last 9 years with BorgWarner, original manufacturer of the Twin Disc (before my time). Normal operating temperatures for automotive and light truck transmission is close to engine coolant temperatures. Not surprising since transmission coolers are submerged in engine coolant inside the radiator. 180 degrees F is typical and must exceed 225 or so before the oil life is reduced due to accelerated oxidation. None of the internal components are adversely affected by such temperatures. Take a car or light truck that operates in high ambient temperature areas (especially trailer towing), pull the dipstick and smell the oil. Oxidation produces a dark color and burnt smell--compare it to a new car. We ran test trips pulling trailers out of Death Valley with 110 degree ambient and would see transmission oil temps as high as 270 degrees. My thinking is that 130 degrees in a tug might be too low rather than too high, likely due to seawater temperature over the transmission heat exchanger. Mark Perlick Steadfast NT37-050"

 

[FF]

Few if any contaminants get into a marine tranny. Perhaps some condensation sitting , but thats about it.

A better temp will help evaporate this moisture faster .

Because they stay clean , some trannt Mfg (as on my Twin Disc) specify non detergent oil.

The additive package can be 10-30% of the oil content , so with non detergent there is more oil in the oil (less chemicals).

It could be worth while to use synthetic in a tranny , if the mfg sez OK.

 

[Nomad Willy]

Would zinc additive help reduce gear wear?

Dosn't gear oil have special additives for heavy shear forces on the gears?

I would think engine lube oil would be lacking in this regard. I use auto trans oil for my BW and I assume it's got an additive package for gear lube.

 

[magicbus]

I've got to change mine when the boat goes back in. Can someone give me an idea of how much they hold? Quarts? Gallons? I'll know when I drain it but would like to get the oil in advance and don't have much use for 30 weight other than this.

Dave

 

[bligh]

I've got to change mine when the boat goes back in. Can someone give me an idea of how much they hold? Quarts? Gallons? I'll know when I drain it but would like to get the oil in advance and don't have much use for 30 weight other than this.

Dave

Mine took about 3 quarts.

 

[Aquabelle]

Dave: if the data plates are still on the gearboxes, they show the amount: I believe for your model it is 1.72 US gallons, BUT allow about another quart per side if you have gear oil coolers.

 

[SAILORPETE]

Twin Disc MG5050

My TD MG5050 marine transmission has 1400 hrs. and is operating fine as far as I can tell. The problem is when shifting from forward to neutral I get a high-pitched whining sound that lasts until the prop shaft stops revolving. I've been told this noise may originate in the transmission. Has anyone had a similar experience? If so, did you identify the problem.

 

[RT Firefly]

Greetings,
Welcome aboard.

 

[Capt.Bill11]

My TD MG5050 marine transmission has 1400 hrs. and is operating fine as far as I can tell. The problem is when shifting from forward to neutral I get a high-pitched whining sound that lasts until the prop shaft stops revolving. I've been told this noise may originate in the transmission. Has anyone had a similar experience? If so, did you identify the problem.

Sounds more like a cutlass bearing squeal.

 

[robie]

High Pitched Whining

My TD MG5050 marine transmission has 1400 hrs. and is operating fine as far as I can tell. The problem is when shifting from forward to neutral I get a high-pitched whining sound that lasts until the prop shaft stops revolving. I've been told this noise may originate in the transmission. Has anyone had a similar experience? If so, did you identify the problem.

Hi SailorPete, I have a 1996 Nordic Tug with Twin Disc MG-506-1 which is at 1700 Hrs. Four 4 weeks ago it started to make a whining sound that lasted about 3-4 seconds after shifting from forward to neutral. Seems to be the same symptom that you experienced. Have you solved the problem? I would really like to know if there is a solution as it seems like the transmission or drive shaft should not be making this noise.

Thanks,
Bruce