What gear oil are you using?

[KEYTEEM]

good morning all,,,
i have put some pretty expense synthetic rear axle lube in i purchased
from a ford dealer ,PART# XY-75W140-QL, i figure it's made for high stress
running and notice that the window after running for just a few minutes
becomes full with foam , once shut off it returns to normal after a few minutes.
was wondering what you guys use and how the window looks after you run
the machine for a few.
how much is too much foam also?
i am running the machine in stock form / no rpm modification .

it sounds good , no strange noices , and i am going to drain it and
switch to 80w90 today to see what happens.

thanx
dennis

[Al_The_Man]

My Excello spindle gear box originally called for gear oil lube, the later manuals for this machine specify switching to transmission fluid, I believe one of the reasons was the non-foaming issues.
Al.

[ChrisJ]

Industrialhobbies used to have a recommendation on their website for the gear oil. Depending on the speed that you run the machine at he had three recommendations.

I bought and use the Mobil (ExxonMobil) DTE Light ISO32. This was Aaron's recommendation for the higher speeds (up to 3600 RPM).

If you are running at 1800RPM, I think his recommendation was ISO68.

Mcmaster-carr.com sells it. It is on page 2026.

Chris

[Randall]

I would stick to what is reccomended. I get very little foaming at 3400 rpm using #10 spindle oil.
Randy Look under product instructions and selecting the proper oil.
Randy

[KEYTEEM]

Excellent, thanx very much i should have the MOBIL DTE 68 ISO
by the 21rst ,
Den.

[NC Cams]

Perhaps the most work with regard to lubrication research has been done by the auto industry. Their need to address durability and power loss (fuel efficiency) has resulted in dramatic improvements in gear box lubricants of late.

I can recall when APG90-140 was MANDATORY gear boxes and rear axles.

However, manual gearboxes are now running Dexron III ATF. Reason: the fluid has been fortified with EP, anti-wear agents, anti oxidation inhibitors, viscosity inprovers and seal conditioners making it suitable for lubing gears and bearings at exteme high and low temps.

In a recent situation, we were having issues with a factory recommended "gearbox lube" as spec'd by the M/T maker. After looking at the cost and availablitiy for the prescribed lube, we tried Dexron. The system has been running for several years now and a certain bearing that we had problems with has been running just fine ever since.

We had a dyno that was frying bearings (24-7 operation) weekly with the prescribed "spindle lube" - in spit of DAILY oil changes. Switched to Dexron and it ran without a hitch for months - change oil weekly just for grins.

BTW: we had some of the so called "spindle" and "gearbox" lubes analyzed before we made the switch to ATF by a former colleague who worked for Marathon. The generic Dexron was found to be a much better lube (additive, viscosity and stability wise) than any of the "factory lubes", especially the viscosity index at "operating temp" - and at a lower cost and better availability.

Oil aeration is common in splash feed systems. The gears churning in the oil makes it hard NOT to aerate. Bubbles on TOP of the oil is one thing, bubbles in a froth IN the oil is something entirely different.

Some machines will be more sensitive to frothing than others. Running overfull will create more frothing than not. However, in drip and/mist fed systems, you want the gears churning in the oil to splash the oil around - the rundown is oftern channeled to the bearings to address the lubrication. If you're not having problems, I wouldn't worry. We saw the same thing and quit worrying....

If you want to be SAFE, run what the make recommends (by the way, our Excello mill lists Dexron as an optional gear box lube). Our cam grinder recommends Mobil Velocite (lightest next lightest 1/2 and 1/2) which we replaced by Dexron. The Dexron runs a tad bit warmer but only 5-10 deg - you can still touch the sump without discomfort after a full day of grinding. If you want to experiment, Dexron is probably your safest bet as an all around and inexpensive lube (we even use it for antirust and cleaning agent on cams after we grind them- cheap and effective)

BTW: a lube sump temp of 150-180F is not an excessive temp for Dexron - can't speak for others. In fact, this temp is good for "flashing" off condensation or other contaminants. For every 10 deg you get above 220F, you cut the lube life in half.

By the way, Dexron/Mercon III mentioned above is NOT to be confused with Type F nor the special stuff recommended for Mopar AT's. Also, generic Dexron is just as good as name brand stuff - it is usually packaged by a name house - and at a better price.....

[Randall]

Thanks for your input. I will try to ask Aaron if he thinks it would be okay and not void the warrenty.
Randy

[KEYTEEM]

I tend to agree with the dexron 3 atf fluid / we have been using it in manual transmissions for many years without any issues regarding lubrication , after putting the the mobil iso 68 recomended oil in it i notice the foam is a lot less than synth gear oil i tried yet it still foams , and this was after only 5 minutes at 1500 rpm of running,so i believe that i also will be trying the dexron in my machine.

[NC Cams]

BTW: Auto transmissions are quite intolearant of foamed oilt - they need hyd pressure to shift and aerated oil won't shift properly.

Hence, Dexron does also have antifoaming agents...

[KEYTEEM]

Yah it would be pretty hard to control a hydraulic circuit with air suspended
in the oil