Recommended Results

Viscosity of Gear Oils

SAE 75W-140 synthetic HD gear oil

Description

Gear oil is a special lubricant for transmissions and differentials in cars, trucks and machinery. Manual gearboxes and differentials use rather highly viscous hypoid gear oils compared to engine oils. Gearboxes do not have an oil pump, so the high viscosity is needed to distribute the oil and to keep it on the metal surfaces, as only the lowermost part of the gears is located in the oil sump.

Depending on the type, these oils contain different amounts of extreme pressure and antiwear additives. The viscosity grades of gear oils are specified according to the SAE Standard J 306. The API (American Petroleum Institute) divides gear oils into 6 classes.

Viscosity Table – Measurement data

SAE 75W-140

Temp. [°C] Dyn. Viscosity [mPa.s] Kin. Viscosity [mm²/s] Density [g/cm³]
0 1551.5 1792.6 0.8655
10 768.20 894.09 0.8592
20 410.55 481.38 0.8529
30 236.53 279.38 0.8466
40 145.40 173.00 0.8404
50 94.468 113.24 0.8342
60 64.333 77.695 0.8280
70 45.654 55.561 0.8217
80 33.544 41.137 0.8154
90 25.409 31.399 0.8092
100 19.749 24.591 0.8031

Gear oil SAE 75W-140 - kinematic viscosity and density over temperature

 

Reference

Measured with SVM™.

Metainformation

Reference Measurement with SVM™
Kin. vis. yes
Dyn. vis. yes
Density yes
Multiple temperatures yes
Related Lubricant, lube, gear oil, hypoid oil, viscosity, SAE