I've noticed a lot of these road going chain drive differential setups are open to the environment, when originally they would have been in a sealed diff or gearbox case in lubricant.

Should these diffs not run in a similar environment to that which they came from? How do you deal with lubrication and protection from dust and debris?

I suppose a dust guard like you get on bicycles would be an easy fix for the later but not sure about the lube.

Most run a "can" of some kind over the business end. This can be filled with lubricant.

Yes it is normal to protect the innards of the differential using some form of oil can and run with lubrication.

Some people use grease - seems to work fine with Quaife type LSDs but with traditional planet/sun gears the grease does not do a good job of lubricating the pins.


Mini QDF14 Chain Drive
Here is a typical kit using a Mini lsd.

The output shafts also have to have oil seals and sealed bearings.
The above kit uses standard Mini output covers with oil seals.
For Sierra chain drives we use bearing carriers fitted with double lip oil seals which stop the oil coming out the output shafts.

Sierra bearing carriers