What type of oil should be used in a Limited Slip Differential?

Millers Classic Green Gear Mineral Oil 90 GL1
Which gear oils do I use in my vintage car that has lots of yellow metal in the gearbox and differential?
11th April 2013
Millers CRX LS 75W90 NT Competition Gearbox Oil

Millers CRX LS 75W90 NT Competition Gearbox Oil

Millers CRX LS 75W90 NT+ Competition Gearbox Oil

Millers CRX LS 75W90 NT+ Competition Gearbox Oil

It depends on the type of Limited Slip Differential (LSD).  The “plate” or “Salisbury” type of LSD uses small clutch plates each side of the differential. These need a special

Limited Slip oil, which contains friction modifiers to reduce squeal and provide smooth power take up. Suitable Millers gear oils have LS in their name. The cam and pawl and torque-biasing differentials do not need an LS oil, just a very good performance gear oil, although there is no harm to be done in running these types on LS oil.

You can find details of the Millers LS gear oils by clicking on the following links:

Millers CRX LS 75W90 NT
Millers CRX LS 75W140 NT
Millers LS 90 GL5

However, there are some exceptions to these guidelines.  Unfortunately synchromesh does not like friction modifiers. They make it slip when it is trying to grip, and could cause the gear change to become difficult.  Hence a problem arises in some front wheel drive cars where the synchromesh gearbox shares the same oil as a plate type LSD.  Millers CRX 75w90 NT fully synthetic competition gear oil is the best compromise, as it has been formulated with this situation in mind.

For details on other gear and transmission oils, please see our full range of Classic Transmission oils, Motorsport Transmission oils and Road Car Transmission oils.