I would have started this process before the differential was installed, but thought I didn’t have a 14mm hex drive socket, as it happens the day after I ordered a new socket I found my original. So it is entirely possible my 360R also had a 14mm hex fill plug.

The fill plug is only accessible if the De Dion tube is not supporting the chassis weight, but my chassis is still on the axle stands, so access was still possible. Access is tight, so I used a breaker bar to loosen the fill plug that initial bit, the ratchet did the rest.

With the plug removed I could break out my high tech fill solution. I have a pump-action gearbox / diff oil filling bottle, but this isn’t needed when gravity can do the work for you.

Take your time with this oil.

The new manual (v1.2 and v2.0) quotes 0.8 litre for the fill, so that’s what I used (slowly). I filled my 360R until a little ran out from the fill plug hole. This was a bit more than the now quoted 0.8 litre, and my 360R had a little dribble from the diff at the first track day, but nothing after that. I have to say, diff oil stinks, so this wasn’t my favourite task, nor was cleaning the tube up after. This Motul 75W140 doesn’t need an LSD modifier, which makes life easier.

Just to make sure that all the oil has made the journey into the diff, I put a tie wrap onto the fill hose, and left it for 10 – 15mins before removing the hose and refitting the fill plug. Obviously it’s now time to remove that “No Oil” sticker.

Tools Used

  • 3/8″ drive breaker bar
  • 3/8″ drive ratchet
  • 14mm 3/8″ drive hex socket
  • Funnel and some hose