Strong sulfur smell indicative of base oil?

[sloinker]

Most rear end fluid/gear oil and some transmission fluid are extremely strong smelling of what seems to me sulfur. Does this indicate anything as far as base oil goes? The ATF4 used in Chrysler products along with most gear oil smells like this. I know crude oil has much sulfur prior to refining, are they leaving some behind for these products or am I smelling something else? The only automotive smell more distinctive is carb dip from the past, yuck.

 

[SonofJoe]

It's very likely to be Sulphurised Poly Iso- Butylene, a common component of gear oils.

 

[kschachn]

Higher molecular weight hydrocarbons and polyalphaolefins are odorless. Most esters (if present) have a pleasant scent, not like mercaptans.

So no it is not indicative of the base oils.

 

[PandaBear]

For gear oil, the stinker the better at protection due to the sulfur additives.

 

[Boomer]

The sulfur in gear oil reacts with the iron in the gears to form iron sulfides. These then provide the necessary lubrication required in the point contact shear that occurs in hypoid gears.