Here's yet another reason why you should change the reduction gear oil...
After reading this post about why (not) to change your reduction gear oil, I decided that safe is better then sorry and got some replacement oil.
However, when I opened the drain plug, nothing happened. After a while a tiny stream of pitch black oil came out. What came out was less then 0,10 liter! There was quite some metal goo on the magnets, but given that there was hardly any oil there, I still think the metal residue is reasonable.
Maybe there wasn’t even enough oil in there to transport all the metal residue to the magnets, so I’m thinking about changing (or at least draining) the oil again after 1000km to see how much dirt will accumulate now that there is oil.
My 2nd-gen Leaf is from 11-2018 and has 45.000 km on it. I never had any problems or noises from the reduction gear, the only reason to change the oil was because I want this car to run forever without problems and my definition of a car lifetime is much longer then Nissan would aim for (my other cars are 45 and 54 years old).
My guess is that something went wrong during production and the reduction gear oil just wasn’t filled at all. What was in there is about what you expect to find in such a gearbox before assembly. There’s also still an option that the gearbox is leaking and the oil leaked out before I bought the car (when it was 1 year old). I never saw any leakage.
These pictures show the magnets and the oil that came out
. It’s actually a bit more then what came out, because it also contains a bit of the fresh oil that leaked when I filled.
Of course, I could have inspected the reduction gear oil earlier and according to the maintenance schedule, the dealer should have inspected it at the 12-month periodical check they did when they sold it to me. Apparently, they didn't. Any thoughts on what would be my best course of action to make sure this mistake has no (or least) consequences for the lifetime of the vehicle?