Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

Needed a quart of 5w30 for the blower  and while at the guy's house got into a discussion concerning gear lube. I have been using Castrol 80-90 Hypoid Gear Oil in my machines gear box . The manual calls for SAE 90 but nobody manufactures a straight weight Hypoid that I could find so I came as close as I could. The thing is the castrol is really viscous in cold weather and being that the gearbox is always coated in snow and turns at so slow a speed I wonder if it ever really thins out.

This Amsoil guy works out of his house and keeps his stock in an unheated shed in his back yard. He brings back a quart of Amsoil stock # AGL80-90  Gear Lube. The container is clear plastic and  was ice cold from being stored in the shed .I turned it upside down and the flow was unbelieveable. Not thick or viscous at all! The guy said it won't thicken more than 90wt. and won't ever be thinner than 80wt at some rediculous below zero degree figure. Needless to say I bought it.

 They make several different kinds of gear lube but the AGL is the replacement for the SAE types. If you consider looking at this product make sure your machine calls for gear oil and not grease.

Good stuff,

Marc  

LOL 

Yeah, I guess the "centipoise" word creates some brain strain to remember those chemistry class lessons & for me, I really have to "backup "in the memory data base!

Here's a chart that gives some common fluid viscosities at room temperatures.

Viscosity Comparisons - @ 70 F

Water 1 cP

Kerosene 10 cP

SAE #10 Motor Oil 500 cP

Castor Oil 1,000 cP

Corn Syrup 5,000 cP

Honey 10,000 cP

Hot Fudge Syrup 25,000 cP

Molasses 50, 000 cP

Heavy Molasses 100,000 cP

So, at -15F, the Amsoil gear lube is in the Hot Fudge to Molasses range, and the dino gear lubes are Heavy Molasses to runny Peanut Butter!

Hey, that sure helps put it in perspective, thanks!

Hi Blue!

Not sure I want them centipoises in my gear box. Thems got lots of legs and chitinous other stuff that could ruin my gears!.

Marc 

centipoise?  Cool word!  I think, however the correct unit for viscosity as it applies to the discussion here, I.E., the ability of an oil to flow at low temperature is the unit for kinematic viscosity, centistokes, rather than the unit for absolute or dynamic viscosity, centipoise.  The two units are related, but not equivalent.  Actually, centistokes equal centipoise divided by density.  Basically, the kinematic viscosity governs the ease with which a fluid flows, while dynamic (absolute) viscosity is the fluid's ability to resist wear and breakdown (shear).  Both measurements are extremely important for your snowblowers (as well as your car).  If your oil doesn't flow at low temperature, it will resist being pumped from the oil sump to the engine and your engine won't be protected.  If the oil flows easily  in the cold, it will quickly reach the engine, but may not be viscous enough to protect moving parts under load and the high temperatures developed when the engine is running.  That's why multi grade oils were developed - they flow at low temperature and still protect at high temperature.  Probably the best units to look at when considering an oil for your blower is viscosity index (VI).  The higher the number, the less difference in viscosity between high and low temperatures.  Manufacturers put additives in the oil to raise the VI.  Unfortunately, the additives usually shear before the oil, which reduces their effectivity with time.  If you're interested in more of this subject, try this link:

http://www.cambridgeapplied.com/news/pdfs/kine_vs_abs.pdf

Warning:  Don't try this if you already have more than a couple of beers in you.

If you're interested in less of this subject, I'll end this diatribe now.  Sorry for the rambling, but that centipoise word really got me going.

the Hun

Welcome Hun,
That article was great, I think. Didn't understand a word of it, so I saved it for later.
Now it didn't explain how come KY Warm feels warm, but further investigation is likely.

robmints wrote:

 I don't care who ya are...that's funny.

hickster

Excellent analogy, Robmints!  The KY Warm manufacturer obviously has utilized numerous additives to raise the VI of their product...to the extent that it's already warm before you put it in, but maintains enough lubricity to prevent wear of the moving parts.  I'll bet if you throw a 5 oz bottle of that stuff in your blower, you won't have to worry about having a hard time starting on the coldest of days..or nights!

the Hun

"The KY Warm manufacturer obviously has utilized numerous additives to raise the VI of their product"

The question is, when you're done using it do you need an IV?   

I think I learned more about lubrication than I wanted to know.