2012 Toy 4Runner rear open diff, LE1605, 30K miles

[INDYMAC]

2WD 2012 4runner with 31,713 miles on unit and 1605 SAE 110 ISO 220 was in service for 29,849 miles of it.

VOA UOA
Iron 1 303
Chromium 0 1
Nickel 0 0
Aluminum 0 0
Copper 0 0
Lead 0 0
Tin 0 0
Cadmium 0 0
Silver 0 0
Vanadium 0 0
Silicon 0 3
Sodium 0 1
Potassium 0 0
Titanium 0 0
Molybdenum 3 0
Antimony 0 0
Manganese 0 4
Lithium 1 0
Boron 88 52
Magnesium 0 0
Calcium 6 2
Barium 0 1
Phosphorous 1154 1100
Zinc 4 7

Water V40C 222 189
TAN 1.78 1.64
Oxidation 10
Nitration 4

 

[Chris142]

I wonder what makes gear oil stink.I don't see anything that would make it stink

 

[MolaKule]

In gear oils you have what is known as the EP additive which is a Sulfur-Phosphorus chemistry. The secondary EP is in most cases a Boron ester.

It is the sulfur AND phosphorus that gives it its odor.

The sulfur (not tested) is most likely at a level of >,= 3,500ppm.

There is a little bit of ZDDP in there to act as one of the anti-oxidants.

 

[xxch4osxx]

Originally Posted By: MolaKule
In gear oils you have what is known as the EP additive which is a Sulfur-Phosphorus chemistry. The secondary EP is in most cases a Boron ester.

It is the sulfur AND phosphorus that gives it its odor.

The sulfur (not tested) is most likely at a level of >,= 3,500ppm.

There is a little bit of ZDDP in there to act as one of the anti-oxidants.
I read somewhere that the sulphur helps create a iron sulphide barrier to help protect gears. Is that true?

 

[MolaKule]

Originally Posted By: xxch4osxx
Originally Posted By: MolaKule
In gear oils you have what is known as the EP additive which is a Sulfur-Phosphorus chemistry. The secondary EP is in most cases a Boron ester.

It is the sulfur AND phosphorus that gives it its odor.

The sulfur (not tested) is most likely at a level of >,= 3,500ppm.

There is a little bit of ZDDP in there to act as one of the anti-oxidants.
I read somewhere that the sulphur helps create a iron sulphide barrier to help protect gears. Is that true?


It is more like a ferrous-phosphide-sulphide film at the molecular level.

 

[INDYMAC]

1605 also has another extreme pressure/AW additive that LE calls DUOLEC. I don't know if it stinks all by itself, but it seems to work. It doesn't show up as a metal on ICP though. Maybe someone here like Molakule knows what it is.

 

[MolaKule]

DUOLEC, like RP's Synerlec, is simply their name for the total EP/AW additive package.