How To: Reduction Gear Oil Change

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Valdemar said:
Closing in on 180k miles with the original oil, no major changes in the gear noise levels.

That's an amazing report. Mechanically speaking I don't think it has to be changed. With every thing in front of motor stripped off it was just a stand on your two feet job plus I wanted to see if adding the Archoil AR9100 additive could make a measurable difference in mileage. I expect the answer is no and have seen no report from the Russian Leaf owner that used the AR9100. I think the active ingredient is mined in Russia.

I hope saving our Leaf is as successful as in your case. Getting a new battery then getting totalled is a bad trip.
 
I changed ours at about 60,000 miles and it was dark and some metal & sludge on the magnetic plugs. I changed it again about a month ago at 125,000 miles and it was still very red and very little metal on the plugs. I doubt I will change it again based on how clean the second change was, I am guess the first one was more of a wear in, I did use the Redline D6 on the changes.

On the first change I did see a .1 to .2 increase in the miles/kwh but on this change I haven't noticed any change.

As with the first change the hardest part was getting the darn plastic belly pan off, breaking half the clips and then getting the pan back on, if it weren't for the belly pan it would have been a 10 minute job...
 
BrockWI said:
I changed ours at about 60,000 miles and it was dark and some metal & sludge on the magnetic plugs. I changed it again about a month ago at 125,000 miles and it was still very red and very little metal on the plugs. I doubt I will change it again based on how clean the second change was, I am guess the first one was more of a wear in, I did use the Redline D6 on the changes.

On the first change I did see a .1 to .2 increase in the miles/kwh but on this change I haven't noticed any change.

As with the first change the hardest part was getting the darn plastic belly pan off, breaking half the clips and then getting the pan back on, if it weren't for the belly pan it would have been a 10 minute job...

BrockWI thanks for your report and outcome of both changes. I expect your data sums the case. Someone had mentioned most of the metal sludge may be generated in the first 5K miles of driving. What you found at 60K miles matches we found at 37K miles.

The Toyota van that ran the red light and came to rest upside down removed our belly pan when he sheared our nose off just missing the front tires by 6 inches.

My son said we could just remove check level magnetic plug in the future to check for metal but from your report I don't see the need.

Valdemar's report of closing in on 180K running the factory fill and no problems indicates to me the two magnets must be doing their job well.
 
My recipe for getting the plastic clips out without damage is to gently wiggle the center pin to shake out the dirt and loosen them up. Then they come out as intended. Eventually the plastic gets old and stiff and they break but that actually takes quite a few years.

I share the majority opinion about the ATF: one exchange is mostly ** optional and more than that is overkill. I don't consider the time I spent on it wasted but I see no reason to ever swap it again.

** One could hedge and just pull out the fill plug for a cleaning one time. As Gale says though, most of the time spent is taking off the bellypan so <<shrug>>. I could see someone who wants to keep the OEM ATF cleaning the plug at 5 - 10k miles one time and calling the job done for at least 100k miles. That way the clips are still fresh :)
 
Yes, our salt / snow / fun winters do a number on anything under the car :) I tried my best and saved about half of the clips the first time and about half this time, luckily I have a large assortment box of plastic clips and just grab what I needed. I did grease up the 10mm screws that go in to the clips to help them last longer.

I bought 3 quarts when I did the first change, so it worked out well to do a second change anyway.
 
GaleHawkins said:
Valdemar said:
Closing in on 180k miles with the original oil, no major changes in the gear noise levels.
That's an amazing report. Mechanically speaking I don't think it has to be changed.
Just a note, in case it was missed, is that Valdemar reported a gearbox (or motor area?) noise 2 years & 15k miles ago.
And now we know the noise is still there. .... https://www.mynissanleaf.com/viewtopic.php?f=38&t=25076&start=60#p562946 ...
(Might be the CV joints half-shafts mistaken for gears or the motor bearings. Those joints can go out any time, but the dealership probably hand-shook the CV joints to see if they seemed loose.)

On the gears & differential box, looks like Nissan engineers, probably targeting ~150k miles life (middle of a bell curve) by design, got it basically right, as this thing can last anywhere from 120k miles to 250k miles on the original factory ATF fluid. Limited evidence though.

If you're not keeping a Leaf past about 100k miles, then don't change the fluid, unless you really want to. I found it easy to DIY, & I got an all-PAO stable "forever fluid" using Amsoil SS ATF in there. .. Truth is, Any cheaper ATF fluid will work OK, since they all do well with just gears & bearings like ours has.
 
If memory serves I first noticed the noise around 120k, it has gotten louder over time but for the last 20-30k has been more or less without changes, I got used to it and don't pay attention to it anymore. It comes from the reduction gear/motor area definitely not from CV joints. That said, it is hard to know what exactly causing it, but worn gears is a reasonable guess. A bit late to change the gear oil I think, so I'll just drive it until no longer can. Not putting as many miles as before on the car, so it should last couple more years and then I'll be ready to junk it.
 
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?
 
Wow that is a totally unexpected finding for an oil change, good thing that you decided to check.

Your gearbox is so clean that i doubt there was a leak at fault, more likely lack of initial fill.

Thanks for sharing. Guess now i have a new project for this weekend.
 
jaap said:
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.
Wow. Awful. .... I did hear of a an EV (Ford Focus EV) that went into the dealership to replace the differential (inside a similar gearbox to the Leaf's) and the technician forgot to put any fluid in. Failure occurred pretty quickly, after a few miles.
I'd guess, like you, that the factory assembly line worker didn't complete the fluid fill task. They squirt some in from a tank, and if that tank actually runs out, they have to stop the line, which they don't want to do. Could be that, of course guessing;;; looks like it.

It did appear like the seals were in very good shape. Clean. If it was leaking before & simply cleaned well, some would have still gotten out when you owned the car, even with the small amount in there, as it was splashing around.

Metal stuff on the magnets looked about normal anyway. Amazing how little it takes in there to grease everything up with only a little splashing & the big gear scooping some up as it's gear teeth get wet down low.

For the future, there is nothing special you can do. Check for leaks once a year. Fill it with any Dexron VI or Mercon LV or Redline or Amsoil ATF fluid or Matic S fluid of course. You did have a good idea to change it again soon to make sure the most metal particles in there get out.
 
So the best is term of efficiency(long car range) is to change change oil to factory fitted Nissan Matic S.
Matic S it is a little expensive. What do you think about LIQUI MOLI TOP TEC ATF 1800 ?
https://pim.liqui-moly.de/pdf/en_GB/liqui/87/P000243
Viscosity at 100 °C 5,8 mm²/s
ASTM D 7042-04
 
mattUK said:
So the best is term of efficiency(long car range) is to change change oil to factory fitted Nissan Matic S.
Matic S it is a little expensive. What do you think about LIQUI MOLI TOP TEC ATF 1800 ?
https://pim.liqui-moly.de/pdf/en_GB/liqui/87/P000243
Viscosity at 100 °C 5,8 mm²/s
ASTM D 7042-04
Liqui Moly Top Tec ATF 1800 is good. LM says it is Nissan Matic S compatible, and indeed the 5.8 cSt viscosity matches Matic S.

LM is a good company, no problems with their quality reputation, good ATF.
Here in the U.S., LM tends to be a little more expensive than most other brands. Not as popular as the many other ATF options in the 5.8 cSt category. ATF fluid works fine in our simple Leaf gearbox, yet GL-4 oil in the same viscosity could be better.

In the U.K., I think Kia sells a bunch of Kona EV cars, so you might buy Kia's GL-4 for the Kona EV. I've always felt that ATF (DexronVI, MerconLV, MaticS, etc.) has unnecessary and possibly problematic requirements to work with clutches using a friction additive that prevents shudder, meaning the increasing friction needed ("Positive u-v curves" in https://www.tandfonline.com/doi/abs/10.1080/10402004.2010.491174?needAccess=true&journalCode=utrb20 ) in a conventional gasoline (petrol) car's automatic transmission, not our Leaf's. Kia avoids all this by specifying a GL-4 oil which will work great in a Leaf too.
 
You mean Hunday Kona.

There is information that Matic S viscosity is 5.2ct in this thread. Anyone have datasheet that can confirm this ?
 
mattUK said:
You mean Hunday Kona.

There is information that Matic S viscosity is 5.2ct in this thread. Anyone have datasheet that can confirm this ?
Right! Hyundai Kona. My bad. I conflate those 2 sister companies sometimes.


One Idemitsu Matic S ATF spec page ( https://www.idemitsulubricants.com/product/atf-type-s-1 ) had 5.2, although I now believe they made a typo. Mistakes on spec sheets happen more than you might think. If 5.2 is correct for the Idemitsu sauce, 5.2 isn't much different than 5.7 or 5.8 anyway.

The actual contract for dealership ATF fluids is with Eneos, and their Nissan Matic S specific juice is 5.7. I think 5.7 is a better number to assume dealership ATF is.
https://www.eneos.us/wp-content/uploads/2021/05/PDS-of-ENEOS-Import-Series-20210430.pdf

Basically any "low viscosity" ATF fluid is fine in a Leaf. No clutch inside, it doesn't care which you feed it. Besides the Hyundai-Kia EV recommendation of their thin GL-4 oil, anything in the low visc column below will work:

uS1wOvF.png
 
jaap said:
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?
One more thing that occurs to me: Make sure you use actual Nissan Matic S when you re-fill, take pictures of the bottles, with a receipt, etc., and document that you at least got it from the dealership (where they should have checked the level). Just because the gearbox could start to make funny noises soon & it may need to be replaced under the powertrain warranty.
 
jaap said:
...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.

It took a bit longer (2.500km) but now I changed the oil again. There was more dirt on the magnets then you would expect after 2.500km, so my assumption that the dirt was not transported because of lack of oil was probably correct. The oil that came out still looked still a bit red, but it was already "mostly black" so I guess by now most of the dirt left the reduction gearbox with the oil.

Next problem.... there is also some red oil on the outside of the gearbox. It seems to be leaking somewhere! The oil is on the right side of the gearbox. It seems to come from a little black tube next to the thick electric cable. What is this tube? Is it an air filter for the reduction box? And if it's so high up, how come it's leaking oil?

It could also be that the right side drive shaft oil seal is leaking and the oil is spread upwards by the drive shaft, but the oil seems to be inside the little tube too. I'm sure it's not the plugs, they are dry and the oil is on the right side of the gearbox, not on the left side where the plugs are.

Any ideas?

The picture (taken from under the motor, upwards), shows the little tube next to the electric cable.

https://owncloud.zb45.nl/index.php/apps/gallery/s/zOP1nqZrJCZKTWk#
 
nlspace said:
Looks like the breather tube--how much oil did you put in when you refilled it?

I filled it until it came out again from the filler hole. That was approx. 1.4 liters.

Where is this breather tube connected? It's hard to see in this exploded view (and also in the engine compartment without taking the engine out).
 
jaap said:
nlspace said:
Looks like the breather tube--how much oil did you put in when you refilled it?

I filled it until it came out again from the filler hole. That was approx. 1.4 liters.

Where is this breather tube connected? It's hard to see in this exploded view (and also in the engine compartment without taking the engine out).


Was the car level when you refilled the gearbox?
 
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