Kroon Oil Classic Gear LS 90

Limited-slip hypoid SAE 90 gear oil for classic differentials

Kroon-Oil Classic Gear LS 90 is a limited-slip hypoid SAE 90 gear oil with an API GL-5 limited-slip listing, made for the transmissions of classic vehicles.

It carries listings for MIL-L-2105B/C, Ford M2C 104-A, GM 1942380 and ZF TE-ML 05C, 05N and 21N.

Key properties

• Grade: SAE 90, API GL-5 Limited Slip, MIL-L-2105B/C
• Also listed: Ford M2C 104-A, GM 1942380, ZF TE-ML 05C / 05N / 21N
• Viscosity: 120 mm²/s at 40 °C, 15.0 mm²/s at 100 °C, viscosity index 125
• Flash point (COC) 214 °C, pour point -36 °C, density 0.874 kg/l
• Total base number 2.0 mg KOH/g, calcium 240 mg/kg, zinc 0 mg/kg
• Pack: 1 L tin

Choosing the right oil

This is the one to look at when the differential is a limited-slip type and the workshop manual asks for a GL-5 limited-slip oil, or names one of the Ford, GM or ZF codes above. A limited-slip unit that is filled with an ordinary hypoid oil can chatter or behave harshly on tight turns, so the correct oil matters more here than in an open differential.

If the unit is an open differential, or a manual gearbox with brass synchromesh parts, check the manual before choosing GL-5 oil; the GL-4 Classic Gear EP 80 and EP 90 oils in this range exist for gearboxes that do not want it.