Question: Chinese Mill Drill gearhead oil type

Hi everyone. Hope someone can shed some light....

I've Googled through this group for past posts on this NG and into Yahoo's MillDrill group to find out what oil should be in the gearhead.

The machine's a brandnew Tong Yang ZAY7032G which Harbour Freight sell as the #42827. See:

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My bugbear is what's the correct oil i'm meant to use in the gearbox? Castrol has advised their Hyspin AWS iso 68 Hydraulic (for lathes said the tech) while Mobil DTE medium ~ heavy duty Hydraulic iso 68 is an equivalent.

I went with the Castrol but the problems started immediately..... The stuff turned to foam in minutes. Castrol suggested add more to the case to cover the gears but it became a rabbid dog spitting the foam out the breather. Next was to drain it on the theory that the assmbly fluids were breaking down the new stuff. It was pretty dirty all right.... added a new batch and that foamed too....

The manual says use SAE 68 which might exist in China or they have some other viscosity rateing so i'm at a loss. I imported the machine directly in a group buy scheme so i don't have an agent to ask. Castrol, bless them have kind of run for the hills on this one....

Any info appreciated.


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I have no idea what SAE 68 is, but I use ESSO Febis 68 which is a gear oil at 250-300 Saybolt. It is anti foaming and has no additive that keeps particulate in suspension like automotive oils. I also use the same oil in the Knee of my vertical mill and the apron of my lathes. Steve

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Steve Lusardi

Hey Pete,

The only "68" I have is a Waylube, and much to thick for your purpose. But I would give Shell's "Tellus 10" a try. It is a spindle oil, and I've seen it used in gear-heads (OKK Cub duplicator). Around here, it is only available in 20 Litre (5 gallon) pails though.

Take care.

Brian Laws>Hi everyone. Hope someone can shed some light....

Reply to
Brian Lawson

Pete, there are guys here who have forgotten more than I know,but- What's wrong with 90 wt hypoid gear oil? I doubt any of this stuff spins faster than automotive/motorcycle gears.

I love the smell of cosmoline in the morning.

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I use a synthetic 50wt gear lube that is common around truck shops. Works great.

Rex the Wrench

Pete wrote:

Reply to
Rex the Wrench

Your mill looks like the little red brother to my green Grizzly mill/drill. I checked the manual for it and it also says to use SAE 68 oil.

I have had the machine a couple of years, now, and have never changed the oil in it. It doesn't get a lot of use. Yes, the oil foams a lot, especially at high speed. It also looks white when foaming.

Someday, when I have nothing else to do, I will change the oil. Don't have a clue as to what to use, like you. May look at some 40-50 weight gear oil with anti-foaming additive.


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Hi Pete, I'm also frantically searching for the same info. It looks like we have the same company's product. Mine is the ZAY7045FG. I'm very impressed with the machine but I don't trust the oil in the machine as it was shipped. My machine's manual also states that one should use SAE68. Shell South Africa advises me to use Shell Tellus ES68. This is apparently hydraulic oil. I sent an email to Tongyong machine works but did not receive a reply from them yet. Nico

Reply to
Nico van der Walt

Pete and Nico

I have an ENCO 12x36 Chinese built lathe and had the same questions. ENCO originally told me 30 wt engine oil but from my experience in rotating machinery (power plant) I knew that was wrong.

Our predictive maintenance Engineer took the recommendations in the manual for lubrication and provided data sheets from Mobil to help me find the right oil.

The headstock and carriage "feed box" call for Mobil DTE light. From the data sheet, this is a 32 viscosity gear and hydraulic oil with anti foam and anti rust additives. You can find this in tool supply stores as 10 wt spindle oil for about 25.00 per gallon. This is also the approximate equivalent of 10 wt R&O gear oil/hydraulic fluid which is availble from parts stores for about 25.00 for 5 gallons. The manual goes on to say that the oil should be drained after short period of light use and the headstock cover removed and the entire gear assby flushed with clean kerosene. In my case, the oil got very dirty after about 30 minutes of no-load running with time spent in each speed. I extended the drain to allow easy and clean draining and repeated the process 4 times until the oil stayed clean. This took a couple of gallons.

The other lubrication points on the lathe called for Mobil Vactra #2. From the refiners data sheet, this is an extreme pressure lubricant for machinery sliding ways. The viscosity is 68. This is readily availble at tool supply stores as #68 way oil and is about 13.00 for a gallon. I have been using it for about 5 years and am still on the first gallon (hobby use).

My source for the way oil is

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(Wholesale tool) I ordered the 10 wt oil from my local parts house.

I hope this is helpful


Reply to
Ron Tyrie

Thanks Ron,

I phoned Mobil SA and they also recommended DTE26 for the gearbox and Vactra #2 for the way oil. I think I'll give that a try.


Reply to
Nico van der Walt

As far as I know, there is no such thing as SAE 68. ISO 68 is the correct term.

ISO specifications for viscosity range from

ISO 7,10,15,22,32,46,68, (non-standard, special purpose, 80),

100,150,220,320,460,680,1000,1500 any thicker and it is almost an OOO grease

These specs relate to a testing temperature of 40 deg C and they cover a viscosity "spread" of +/- 20%. ie 46 -20% = 37, +20% = 55, 68 - 20% = 55, +20% = 82, 100 - 20% = 80

Multigrade oils are tested at 2 viscosities, 40 & 100 deg C. The less relative difference between the two, the higher the Viscosity Index and the better the oil quality. (Explanation simplified) From memory of about 35 years ago the F. temps were 100 & 210 deg F, Americans may still be using Saybolt and other obsolete standards.

Many oil companies have a +/- 10% tolerance over the nominal viscosity, my ex employer had +/- 5% tolerance up to the time I retired nearly 10 years ago, I have not kept up to date since.

A good hydraulic oil has anti-foaming and corrosion inhibitors and a few other additives to reduce wear etc.

Alan in beautiful Golden Bay, Western Oz, South 32.25.42, East 115.45.44 GMT+8 VK6 YAB ICQ 6581610 to reply, change oz to au in address

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