jaap
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Re: How To: Reduction Gear Oil Change

Thu Oct 14, 2021 1:35 am

nlspace wrote:
Wed Oct 13, 2021 4:46 pm
jaap wrote:
Wed Sep 22, 2021 1:58 am
...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!
Oh yeah now we know how and why it was so extremely low on oil--it all puked out the tube with the missing breather valve.
I think most likely is there are parts missing (and that also caused the low oil level). I'm quite sure the dealer never even got the bottom plate off although they should have done that during the 1-year maintenance check they said they did when they sold it. So I'll go back to the dealer, see if they can get me this breather and ask what they are going to do about the probable damage to the gearbox.

voltamps
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Re: How To: Reduction Gear Oil Change

Sat Oct 16, 2021 9:19 am

On jaap's gearbox issues, Nissan may try to wiggle out of the Powertrain Warranty (only 2 years left on it) since somebody at some unknown point broke off the breather cap. Or, could be Nissan might think it just broke off on it's own, which would be covered under warranty. They could also point to the annual oil level inspection that is supposed to be done & cancel the warranty cuz of that.

Right now, as long as the gearbox isn't making funny noises, it's not considered broke. Strange case.
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GaleHawkins
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Re: How To: Reduction Gear Oil Change

Wed Nov 03, 2021 6:04 am

jaap wrote:
Wed Sep 22, 2021 1:58 am
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?
Awesome photos and logic.

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Stanton
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Re: How To: Reduction Gear Oil Change

Wed Nov 03, 2021 9:08 am

Finally "pulled the plug" (so to speak) on my Reduction Gear Oil Change using Valvoline ULV.
Thanks to @knightmb for all of his (early) postings/work.
It's probably too soon (and temps too cool), but early indications show a slight improvement in miles/kWh. For the record, the oil coming out was pretty "clean" (~86k miles) and the oil going in has yielded smooth performance; I'll post an update when I have more meaningful data.
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voltamps
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Re: How To: Reduction Gear Oil Change

Fri Nov 05, 2021 4:21 pm

jaap wrote:
Thu Oct 14, 2021 1:35 am
I think most likely is there are parts missing (and that also caused the low oil level). I'm quite sure the dealer never even got the bottom plate off although they should have done that during the 1-year maintenance check they said they did when they sold it. So I'll go back to the dealer, see if they can get me this breather and ask what they are going to do about the probable damage to the gearbox.
Interesting to hear the dealership's and maybe Nissan's warranty response on this issue. Don't forget us.
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jaap
Posts: 8
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Delivery Date: 15 Nov 2018
Leaf Number: 123456

Re: How To: Reduction Gear Oil Change

Sun Nov 14, 2021 12:18 pm

voltamps wrote:
Fri Nov 05, 2021 4:21 pm
jaap wrote:
Thu Oct 14, 2021 1:35 am
I think most likely is there are parts missing (and that also caused the low oil level). I'm quite sure the dealer never even got the bottom plate off although they should have done that during the 1-year maintenance check they said they did when they sold it. So I'll go back to the dealer, see if they can get me this breather and ask what they are going to do about the probable damage to the gearbox.
Interesting to hear the dealership's and maybe Nissan's warranty response on this issue. Don't forget us.
It took a while before I had time to visit the Nissan dealer... this week I finally went there.

The workshop manager at the Nissan dealer agreed that having almost no oil on the first change was a strange situation. There was plenty of oil leaking from the reduction gearbox again, but it was so much that it was very hard to find out where it was coming from. They made a lot of pictures, because they seem to agree "something went wrong at Nissan", although we're still not sure what.

To find out where the leakage comes from, we compared the construction of the breather with another Leaf of the same type. It looks the same, it also has the tube hanging down. But that car is completely dry.

Since we could not find the leak, they kept the Leaf for a few hours, cleaned everything and checked the oil level. There was still enough oil in there, so the leakage wasn't that bad. They made a test drive, but after that, no new oil leakage was found. So I've taken the car home and will drive around for a week, after that we'll check again.

The workshop manager thought it might be possible I over-filled the reduction gearbox when I filled it myself (both times, in that case). I find that hard to believe, because I measured what went in and it was very close to 1.4 liters. Also, I had the side plug out while filling, so it overflowed a bit and I let it drip for a while. I guess that even if here was 1.5 liters in the gearbox, that should not come out through the breather.

Next friday, I have another appointment at the dealer, and we'll have a look if there is new oil leakage or not. Maybe it was a matter of over-filling, after all. But even if that's true, that doesn't explain why there was only 0.1 liter in there to begin with.

The good news is that the gearbox does not make any strange noises and the oil that they took out as a sample looks very clean. So probably the damage to the gearbox is limited, if any.

To be continued...

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knightmb
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Re: How To: Reduction Gear Oil Change

Sun Nov 14, 2021 3:42 pm

jaap wrote:
Sun Nov 14, 2021 12:18 pm
The workshop manager thought it might be possible I over-filled the reduction gearbox when I filled it myself (both times, in that case). I find that hard to believe, because I measured what went in and it was very close to 1.4 liters. Also, I had the side plug out while filling, so it overflowed a bit and I let it drip for a while. I guess that even if here was 1.5 liters in the gearbox, that should not come out through the breather.
I've done a dozen of this gear oil changes now across many multiple generations of Leafs when doing my research some time back. It takes the full 1.4 liters just to reach the bottom of the second plug when the Leaf is level, but even that is not enough to really "over-fill" it. To do that, you would have to take the top "3rd" hidden plug out and then continue to fill at that point to really over-fill it. Since you filled at the second plug like the manual says, I would be highly doubtful that you did an over-fill unless the Leaf was at such an extreme angle facing down and forward that it wouldn't be safe. :lol:

But, even if you did manage to actually over-fill it, the extra pressure would just blow the excess out the breather anyway, but unless the tube comes out lower than where it started, I don't see it making a suction pump to just pull everything out at once via gravity.
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moo
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Re: How To: Reduction Gear Oil Change

Thu Nov 18, 2021 1:59 pm

I also just did a transmission fluid change for my 2012 leaf that I bought used yesterday. I also used the Valvoline ULV fluid. Since it is becoming winter my efficiency is all over the place. I am excited to see the potential efficiency gains or preemptive failure of the gear box. I still need to put the bottom cover back on to get an idea if there are any immediate subjective differences. Will report back with some non-scientific results soon.

jaap
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Re: How To: Reduction Gear Oil Change

Fri Nov 19, 2021 4:07 am

jaap wrote:
Sun Nov 14, 2021 12:18 pm
Next friday, I have another appointment at the dealer, and we'll have a look if there is new oil leakage or not. Maybe it was a matter of over-filling, after all. But even if that's true, that doesn't explain why there was only 0.1 liter in there to begin with.

To be continued...
So, I went back to the dealer this morning. There was oil leakage again and when opening the side plug, oil came out, even though they opened it last time too. So the leakage wasn't caused by over-filling, that's for sure. The leakage seems to come from the little tube, but also the dealer doesn't know why. It remains an unsolved mystery.

Next step: I will bring the car to the dealer again on November 29th. They will replace the oil with the "Genuine Nissan Oil". They have to order that, because they never filled a Leaf before (!). With the original oil in, they'll do more tests and searching to see why it's leaking and how.

In the mean time, we can just speculate on what's happening...
  • Why is it leaking from the tube? Could that be cause by a faulty breather?
  • How come oil comes out when you open the side plug, even though that was opened before and drained until it didn't leak any more?
  • Could the oil be foaming, causing increased volume?
  • Is there another liquid that could leak into the gearbox, raising the oil level? Coolant maybe? Any cooling pipes nearby?
The dealer does not believe in internet Fora as a source of Leaf-wisdom, but it doesn't really look like they have their own source of knowledge either. Maybe we can come up with the right answer before the 29th.

To be continued!

nlspace
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Re: How To: Reduction Gear Oil Change

Fri Nov 19, 2021 8:41 am

jaap wrote:
Fri Nov 19, 2021 4:07 am
...

In the mean time, we can just speculate on what's happening...
  • Why is it leaking from the tube? Could that be cause by a faulty breather?
  • How come oil comes out when you open the side plug, even though that was opened before and drained until it didn't leak any more?
  • Could the oil be foaming, causing increased volume?
  • Is there another liquid that could leak into the gearbox, raising the oil level? Coolant maybe? Any cooling pipes nearby?
Most likely a faulty breather or faulty/clogged tube. They should have just replaced all the tubes and breather, then you could rule out possible culprits. Or at the very least run a wire thru the tubes to verify they aren't blocked with dirt or insects, and replace the breather.

Oil will come out due to thermal expansion from the higher temperature of driving and the resulting increase in volume and ullage pressure. That is the reason to have the breather tube to provide for expansion. The theory is that the vapor will rise into the breather where it will condense with cooler temperature and the liquid can drip back down to the gearbox; only air fumes should travel thru the breather vent.

If there were a coolant leak then why was there only 0.1L in the gearbox--you would expect it to be full of something other than oil? That possibility doesn't seem likely.

i'm guessing there is a blockage or defect in the housing nipple, the tubing or the breather causing this malfunction.

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