How To: Reduction Gear Oil Change

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dm33 said:
You should never have to replace this oil. There are lots of lubricants all over a car that you don't need to change. This is one of them. Only if there's a leak. The notion of changing this oil is a left over from having an ICE. Doesn't apply. Likewise you don't need to change oil in the engine/motor. The bearings are lubricated for life unless there's an issue.

Forgive me for being a little harsh, but it must be said for the sake of the other posters....

You really should not be giving anyone any advice on NOT changing fluids on cars, as your lack of mechanical experience is so blatant...

1) Car companies with all cars today have conveniently "forgotten" to place antifreeze, brake fluid, power steering, and transmission fluid changes on their "maintenance schedules", or even say that the fluids are for "lifetime". That is another way of saying that in 10-12 years of use (when the car has 100K miles and the car breaks down), you will write the car off and buy a new one. If you want to keep a car going to 200K+ miles, you will need to change ALL fluids.

2) there is no "lifetime" fluid on a car. ALL fluids deteriorate in their protection properties or collect harmful substances that need to be removed. Transmission fluid can go longer than oil changes because it is a sealed system, and does not collect byproducts of gas combustion. It also does not reach high temperatures that will degrade it. HOWEVER, transmission fluid lubricates all the gears and rods that spin at very high speeds, AND collect fine metal particles from the wearing of the mechanism. That is why they put a magnet in there to collect the steel shavings.. (PS - that fine paste on the tip of the bolt IS steel shavings). So, after 1000s of miles, you must change the engine oil and transmission fluid (even if it looks good) to remove the harmful metal shavings that will otherwise chew up the parts of the transmission.
 
Do be fair, on old Automatic transmissions with many miles, if the user has never replaced the fluid, you're better off not replacing it as the fluid couplings now depends on the more viscous fluids to turn the gears.
 
Tunamelt said:
Do be fair, on old Automatic transmissions with many miles, if the user has never replaced the fluid, you're better off not replacing it as the fluid couplings now depends on the more viscous fluids to turn the gears.

Yes, but that argument does not hold on a Leaf or a CVT transmission. On these cars, even if you have never changed the fluid, you can only help the car if you change it. you need to get out the junk along with the old fluid....
 
LeftieBiker said:
If there is a problem with reusing the metal gasket it will likely occur at least a few months from now, in the form of the plug loosening. I'd have used thread lock if I had to reuse the gasket.
If anything you'd have a leak. I reuse the crush washer once or twice before replacing it (because I always forget to get a new one before draining the oil. :p ) I take it off, wipe it down and flip it over when I reinstall it, then properly torque the plug. Never had an issue. If the washer is severely deformed from someone over torquing it, then it won't seal.
As long as the plug is tight, it's not going to fall out.
 
Tunamelt said:
Do be fair, on old Automatic transmissions with many miles, if the user has never replaced the fluid, you're better off not replacing it as the fluid couplings now depends on the more viscous fluids to turn the gears.
On a very old automatic (any automatic for that matter...) you don't want to FLUSH the transmission. A drain and fill isn't going to hurt it.
 
powersurge said:
1) Car companies with all cars today have conveniently "forgotten" to place antifreeze, brake fluid...

2) there is no "lifetime" fluid on a car. ALL fluids deteriorate in their protection properties or collect harmful substances that need to be removed. Transmission fluid can go longer than oil changes because it is a sealed system, and does not collect byproducts of gas combustion.

1) I thought that Nissan says to replace the brake fluid every one to two years and the antifreeze at 150,000 miles. But still, there are other "forgotten" fluids.

2) Transmissions and differentials actually have a breather somewhere, so they're not truly sealed. As air expands and contracts due to changing ambient temperatures, barometric pressures and changing in altitude, dirt eventually finds it's way into the oil through that breather. Either that or there is a little filter where air can go in and out but not dirt. But after a while those can become clogged up, sometimes rather quickly in certain conditions, and then you build up pressure in the transmission or differential housing and lose your seals and leak oil.
 
estomax said:
some preliminary results are in over the last 3 weeks of driving and i seem to be settling in at 3.9 miles/kwh vs the 3.7 that i had averaged for the month and a half that i reset before that. Ambient temperatures here in the Seattle area have been about level.

this is obviously not very scientific but there are some single digit efficiency gains possibly to be had by swapping to the redline D6 fluid over stock fluid.

This is encouraging. Everything still running fine?
Since I was going to change anyway now that I'm out of warranty I think I'll try that Redline D6. Five percent is a pretty decent improvement.

Do you recall what length of hose was required?
 
i had something in the 3 foot range for the hose. everything is still fine, 6 months and about ~8k miles later.

the efficiency improvement was not scientific to say the least but if you do it and can correlate a similar effect then that's worth something
 
In case anyone wants a source for the crush washers
https://www.amazon.com/gp/product/B072627HB9/
pack of 10 but cheaper than getting 2 from Nissan and seem to be a common size so maybe useful for other vehicles
 
A Nissan dealer sold me the wrong sealing washers so I will wait until tomorrow to refill. The correct size is 18 mm ID and 24 mm OD (flat aluminum sealing washer). The dealer sold me copper crush washers that were only about 1/2-inch ID even after I asked for confirmation of size and material since they looked small and I expected aluminum. The old oil was black and there was a lot of debris stuck to both magnets with slightly less than 64k miles so I will be changing the oil more frequently in the future. I will try to post some photos later.
 
Did this about a month ago@62k miles, the mi/kwh meter has increased from 4.7 to flopping between 5.0 and 5.1. About 950 miles into the fluid change w/ Redline D6. The before estimate was determined over the course of the month preceding. The power pulled from the wall as also decreased by the same. 2011 Leaf.
 
I replaced the gear oil on our 2011. It was dark in color and felt less viscous than the new Redline D6. Little accumulation on the magnets. After 7 years of no car maintenance I did not realize I did not have the Allen wrench sets anymore. Gave them away to afriend years ago to unblock the garbage disposal. So after removing the tray/shield, I put the wheel back for a day. The next day I was too lazzy to remove the wheel again and did the oil change and put the tray back without jacking the car. I have long hands but I am not a slim guy. A steep driveway helped when I reached for the back bolt on the tray.
 
If I'm understanding this right, the gear reducer in the Leaf is analogous to a transfer case in a 4x4 truck. In my Titan I changed the transfer case fluid (plain old ATF) about every other third engine oil change. The truck was running synthetic engine oil with lab testing at each oil change. The oil change interval was 10,000 miles.

The transfer case was a sealed system but unlike the transmission had no cooling system. The oil after 30,000 miles was downright nasty.

Teflon tape can be used on the threads of the drain/fill plugs. We used that on our transfer case plugs on the trucks with no issues, but eventually I just slapped the plugs back in without any further enhancements. No leakage over 100K miles there.

I'll be doing this fluid change soon. I didn't realize it was something we could maintain so many thanks to the OP of the thread for this information. I have a couple cases of AMSOil synthetic ATF leftover from my Titan that I've been wanting to use up and a couple bottles will work fine for the Leaf.

I have pump spouts on the ATF bottle. So I don't need to use a hose from above. At least I'm hoping it will work out that way.
 
I did this service at 48K miles..

The fluid was not nasty... It is not like a differential that turns into sludge.. It was in the brown range (from the original red).

You need to do this with the car level. There are 2 ways to do this. One, with the car lifted at 4 points (level).

- you take off the large engine compartment protector from underneath.
- you first remove the top (fill plug), and then the bottom drain plug.
- you DO NOT NEED to use Teflon tape... no good
- fill until the fluid is generously coming out of the fill hole.

Alternate way to fill - After you drain, replace the drain plug, and lower the car back to level ground...
- With a section of tubing you can refill until the extra comes out, and replace fill plug from above. There is room to squeeze your arm through the engine area to hand tighten the plug, and finish with a closed end wrench.

easy.
 
I checked the level per the maintenance schedule at 15k miles/2 years. I used a bunch of extensions so I didn't have to pull the belly pan.

This is what the plug looked like — should I be worried?!
geSVlNQ.jpg
 
I would say that is normal. If you are worried, clean the plug and check it again in a year. It will probably be much cleaner next time. It's normal for some metal to wear off the gears as they break in, that's why the plug is magnetic.

I'm more used to seeing powdery looking deposits instead of the longer shard-like metal on your plug but it could just be the magnification of the picture or maybe it's just because it's new. Or maybe if you wipe the plug the deposits are actually smaller and they just lined up in that shape due to the magnetics....
 
goldbrick said:
I would say that is normal. If you are worried, clean the plug and check it again in a year. It will probably be much cleaner next time. It's normal for some metal to wear off the gears as they break in, that's why the plug is magnetic.

I'm more used to seeing powdery looking deposits instead of the longer shard-like metal on your plug but it could just be the magnification of the picture or maybe it's just because it's new. Or maybe if you wipe the plug the deposits are actually smaller and they just lined up in that shape due to the magnetics....
Thanks, I'm not particularly worried. I just have no baseline. I did wipe it clean and will check it before the powertrain warranty is up :)
 
Goodbar said:
I checked the level per the maintenance schedule at 15k miles/2 years. I used a bunch of extensions so I didn't have to pull the belly pan.

This is what the plug looked like — should I be worried?!
https://i.imgur.com/geSVlNQ.jpg

Looks fairly normal. Manufacturing the gear teeth perfectly polished and mated to each other would be prohibitively expensive, so it's done inside the gearbox by the driver. Most of those metal particles are from the first few thousand miles of use.

But -- the effort it takes to get the fill plug out is not all that much more than draining and re-filling. I like the idea of getting the initial wear-metals out of the case.
 
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