Hi Chris Eaton!!
On Mon, 28 Apr 1997, Chris Eaton wrote:
> hypoid90 or 20w50 sitting on your shelf in your garage.But I reccomend
> motor oil the hypoid stuff tends to be a little thick.
Well, your reccommendation is a little bit uninformed...
Quoting from the "ESSO (Canadian EXXON) LUBRICATION GUIDE",
"The SAE number designations for GEAR OIL grades were purposely chosen
to be completely different from SAE ENGINE OIL grade numbers. The
intention was to minimize chances of using the wrong type of lubricant,
particularly since they differ so much in composition and performance
qualities. However, the SAE 70W, 75W, 80W, 85W and 90 grade gear oils
overlap the viscosity range of engine oils. For example: an SAE 75W
gear oil of 5.5 cST at 100' Centigrade is typical of an SAE 10W engine
oil; an SAE 80W gear oil of 8.0 cST at 100' Centigrade is typical of an
SAE 20 engine oil; an SAE 85W gear oil of 12 cST at 100' Centigrade is
typical of an SAE 30 engine oil; and an SAE 90 gear oil of 15-20 cST at
100' Centigrade is equivalent in viscosity to an SAE 40 or 50 engine
oil."
For our American friends, 100' Centigrade is 212' Fahrenheit (sp?), and
the cST (centistokes) is a measurement of viscosity.
The viscosity measurements methods are a whole subject unto themselves.
To recap: 75W - 10W
80W - 20W
85W - 30W
90W - 40 ~ 50
When in doubt, DO WHAT THE FACTORY MANUAL ADVISES FOR YOUR YEAR OF
MANUFACTURE FOR THE COMPONENT; ie. - if you have a '75 tranny in a '62
"B", use the factory info on the '75 tranny when choosing gear oil.
Note the KEY words are "WHEN IN DOUBT". You may have excellent advice
to choose something else, ie a synthetic oil... don't accept any
guessing, or "I think", or "It seems to me" type advice, and don't
dispence any of the same ilk.
TTUL8r, Kirk Cowen
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