Transmission oil- can I use mulitgrade?

Nomad Willy said:

NightCrawler,

Go figure what?

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Figure of speech. . .as in doesn't seem to make sense but it is what it is. ?

"Figure of speech. . .as in doesn't seem to make sense but it is what it is"

Used engine oil may very will be depleted of most of its adative package.

Since its of no use in a tranny , if the used oil is clean , why not use it?

North Baltic sea said:

I have mg5061 gear and service manual say: use only SAE-API service class CD engine oil certified to meet TO-2 transmission oil specification or type C-3 transmission fluid. Also approved is SAE-API service class CC engine oil.

Steady operation conditions(GEAR OIL) 150°-185° f SAE30 and 185°-210° f SAE40

And Multi-viccosity oils (i.e. 10W-40, etc.) should not be used in Twin Dick marine Transmissions.

I hope help your oil questions.

NBs

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Do exactly as the manufacture says. They have engineers who have tested this for months to find the correct product.

Capt. Lee,
Good advice but there’s more to it.
I flew an UL aircraft and used BelRay motorcycle racing synthetic oil in my two stroke engine.
Went to an airshow and talked to a factory rep for my engine. I asked him about synthetic oil and he told me to follow the recommendations in the manual. The manual said “not to use synthetic oil”. On full power climb-out I ran at rated rpm (6000) and at max CHT (425 degrees). I wanted all the protection I could get.

We argued for some time and eventually he changed his tune. Said they didn’t have time to test every lubricant that came along.
The engine was a snowmobile engine that was prone to sticking/seizing. Eventially Cuyuna (the engine) came out w their own oil rebranded oil and called it their “40-1 oil”. 40-1 was fine but the dino oil required running too rich (to keep the engine from seizing) and then there was a carbon and soot problem.

This was a case where the manufacturer was wrong. Using this engine for prime power for aircraft was not a good choice and Cuyuna went out of business. The original application was snowmobiles. There were air cooling problems as well.

This example of there being situations where an engine manufacturer may callout an undesirable lubricant is not a very good one as the engine production was only in small numbers and the vehicle application was quite different. But many of our “marine” engines are much the same .. taken from another application.

But whenever an engine manufacturer specs things like lubricants marketing tends to get involved often as they should be. If I had been in Cuyuna’s situation I would have specified a CHT redline for dino and syn separately and been frantically looking for a replacement engine.

But there ARE times where manufacturers recommendations for oils can be changed by the user with excellent results. But before you put bananas in your crankcase consider that doing other than what’s recommended re engine lubricants is almost always a bad Idea. As fgarriso wrote above.

NightCrawler said:

Tom, some great info on debunking the mythical alphabet soup of lubricants. I went through this exact same exercise in 2016 with our TD MG506-1's. I went back and forth with TD and finally engaged some technical services folks at Amsoil, a product I use exclusively. I did not see any references to synthetic oils in the thread and thought I'd share our results. First, TD's spec was "any two of the three listed below" which included one motor oil, one transmission fluid and one gear oil. So, since they seemed to like motor oil in these boxes the best, I went with 15-40 Diesel oil. (synthetic of course) A couple of things happened.

First, a persistent howl in the port tranny at 1,000 RPMs dissappeared. Second, gear oil temps declined by about 30 degrees after a full day of running. Over 4,000 hours on both and they hum like sewing machines.
One common misconception is the oil will break down and go from 40w to 15w. This is not true.

As an aside, one of the docs I got from TD listed "used motor oil" as an acceptable fill. I'm thinking these things may not be that fussy, as long as you are using the right type of lubricant, motor oil, gear oil, transmission fluid - based on your best info for that particular mixer. On the transmission tags mine say "check the manual for proper lubricant" I have the manual and it says "check the tag on the transmission for proper lubricant"

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My 1987 GB 42 has Twin Disc 502 gears and I find myself with a similar “Catch 22”. The manual says look at the plate on the transmission, but the plates have long since ceased to be readable. Anyone know what the appropriate gear oil is for these transmissions?

Mackin said:

My 1987 GB 42 has Twin Disc 502 gears and I find myself with a similar “Catch 22”. The manual says look at the plate on the transmission, but the plates have long since ceased to be readable. Anyone know what the appropriate gear oil is for these transmissions?

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Call Twin Disc they will help you out....

I would think it would have mostly to do w if they are hydraulic or manual.
Hydraulic = Auto trans fluid or special oil.
Manual probably 90w gear oil.
In a pinch .... oil.

Why is lube oil for the BW Velvet Drive trans usually referred to as auto trans “fluid”? Why not “oil”?

The 502 is also a 30 weight engine oil.
But check with T.D. to satisfy yourself.

I belive it is 30wt transmission/gear NOT engine oil.

C lectric said:

The 502 is also a 30 weight engine oil.
But check with T.D. to satisfy yourself.

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Thanks. The combination in various posts of: (i) the range of viscosities suggested (everything from 30 wt to 90 wt), (ii) the debate between the suitability, or otherwise, of natural versus synthetic oils, and (iii) the controversy concerning whether one can use engine oil or only gear oil, leaves me feeling more than a little mystified. When you add to that all the dire warnings about the catastrophe that looms for one’s transmission(s) if one uses the wrong lubricant, I confess it leaves me feeling more than a little apprehensive.

Mackin said:

Thanks. The combination in various posts of: (i) the range of viscosities suggested (everything from 30 wt to 90 wt), (ii) the debate between the suitability, or otherwise, of natural versus synthetic oils, and (iii) the controversy concerning whether one can use engine oil or only gear oil, leaves me feeling more than a little mystified. When you add to that all the dire warnings about the catastrophe that looms for one’s transmission(s) if one uses the wrong lubricant, I confess it leaves me feeling more than a little apprehensive.

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Best is to follow your manufacture recommendations.

Alaskan Sea-Duction said:

I belive it is 30wt transmission/gear NOT engine oil.

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Actually 30W engine oil. But NOT multi-viscosity such as 10W-30. Had a discussion with the Twin Disc tech department on this. Multi-vis causes problems as the long chain polymers added to achieve multi-vis shear down in the hypoid gears, resulting in 10W rather than 30 within a few hours. At least that was their story.

Thanks. That’s helpful. Going to try to check with a local repair shop tomorrow (one that Twin Disc mentions on their website as an authorized repair facility). Don’t understand why Twin Disc doesn’t specify in their manuals what the proper lubricant is for any given reduction gear (instead of telling you to go to the plate on the gear itself, which, with anything more than a few years old, is likely to be, at the least, impractical or, in my case, impossible. It’s annoying to have to waste time and energy trying to find out something so basic. You’d think you were asking them for the launch codes!

I use 30 weight engine oil in our PRNs.

I also have MG 502 and use a 30 wt engine oil. Have attached a photo of tbe Service Manual. Unfortunately I only have a hard copy so can't post the whole document.

Thanks; that’s a big help. Much appreciated.

I have a digital version of the MG-502 Service Manual I can provide. Tried to upload to library but file is too large. I can email if you send your email address to me. Also, while you are down in the engine room check to make sure your drive shaft coupler bolts are tight! Don't ask me how I know but I posted an account of mine coming loose a few days ago.

Night Crawler wrote;
“Having done some deeper research, I found this to be an old wives tale. Good synthetic oil does not shear into the lower grade”

It did in the early days of synthetic oil. But it has’nt been a problem for a long time. And now one dosn’t need to stew about the cost of synthetic .... it’s actually cheap.

Speaking of syn/dino has anybody experienced an engine manufacturer saying not to use dino oil for a need other than heat as is the case w turbochargers?

Ok folks there may be some bad info here.

In my Cat Marine Engine (3208) and Twin Disc (MG-507) manuals it calls for certified TO-2 or C-3 test specification. TO-2 is the old spec. The replacement spec is TO-4. Again this is GEAR oil, not motor oil.

For Delco it is Delco Torqforce 30wt

For Cat it is TDTO 30wt.

Check your manuals. I can't stress that enough. Most of the spec may have been updated. Pretty simple.

As FF always says "read da book".

Reading a number of books , my guess is many trannys will be happy with non detergent engine oil of the correct weight..

The TD in our Navy Launch used 5 quarts of 50wt Non detergent.

Its hard to find so the simple method is to have your NAPA guy order a full case for you . so nothing will be left over that is hard to sell.

Most can do this easily , tho you may have to wait a week or more for delivery as his distributor will have to special order the case.

Thanks

I’m amazed! Five pages of comments about oil. My Twin Disc says change oil at 1000 hours running time. There is no combustion so no worries about that type of contamination. With the average of 200 hours a year, many on here may not even own their boats for 1000 hours. Which is a digression I admit. ZF? Borg Warner? Really?

Manual or manufacturer, the rest is just opinion, rumour and guessing.

Alaskan Sea-Duction said:

Ok folks there may be some bad info here.

In my Cat Marine Engine (3208) and Twin Disc (MG-507) manuals it calls for certified TO-2 or C-3 test specification. TO-2 is the old spec. The replacement spec is TO-4. Again this is GEAR oil, not motor oil.

For Delco it is Delco Torqforce 30wt

For Cat it is TDTO 30wt.

Check your manuals. I can't stress that enough. Most of the spec may have been updated. Pretty simple.

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Many if not most good single weight CD motor oils meet the TO-2 specification, for example Shell Rotella T1 30W or Delo 400 30W. These are marketed as a motor oil, not a gear oil. There are tractor hydraulic oils that meet TO-2/4, but are harder to find on the dock. Many oils marketed as gear oils have hypoid gear EP compounds in them, and these are specifically prohibited by TD. It is all in the manual, but proprietary oil specs can be a quagmire. There is really not a heck of a lot of difference between gear and motor oils in a 30W.

Also, true synthetic multi-vis oil may not shear easily, but what is allowed to be marketed today as "synthetic" is quite loose. Most of them are dyno oils that have been "converted" to synthetic, and the additive packages that achieve the multi-vis rating are similar.