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Re: How To: Reduction Gear Oil Change

Posted: Tue Oct 06, 2020 7:50 pm
by GaleHawkins
This data may support the first change at 5K miles. Nissan changed all gear boxes fluids after first 600 miles on my new 1973 B-110.

Re: How To: Reduction Gear Oil Change

Posted: Tue Oct 06, 2020 9:48 pm
by HRTKD
Considering that many manufacturers are setting the oil change interval on transmissions to more than 100,000 miles, the oil that Nissan put in the gearbox doesn't seem to be high quality. Medium quality at best.

I understand this isn't a transmission that has a cooler and filter. But even transfer cases are rated for a lot of miles before a change is scheduled.

Re: How To: Reduction Gear Oil Change

Posted: Tue Oct 06, 2020 10:00 pm
by Nubo
knightmb wrote:
Tue Oct 06, 2020 7:23 pm
The report is here :mrgreen:
I do give credit to Blackstone for having a real person look at and analyze about the test results. Or at least it seems that way. If not I don't want to know. :lol:

Re: How To: Reduction Gear Oil Change

Posted: Tue Oct 06, 2020 10:23 pm
by HRTKD
Nubo wrote:
Tue Oct 06, 2020 10:00 pm
I do give credit to Blackstone for having a real person look at and analyze about the test results. Or at least it seems that way. If not I don't want to know. :lol:
All my reports from Blackstone were custom. The one where I forgot to change the oil on time was kind of funny. It started with, "You went too far."

Re: How To: Reduction Gear Oil Change

Posted: Wed Oct 07, 2020 5:47 am
by Steelcity
Knightmb & olipan4 thanks for posting, good info. I'm glad I changed mine at 34k and 7 yrs old . Went with synthetic for less friction and better range . Still waiting on that range thing.

Re: How To: Reduction Gear Oil Change

Posted: Wed Oct 07, 2020 7:07 am
by knightmb
Steelcity wrote:
Wed Oct 07, 2020 5:47 am
Knightmb & olipan4 thanks for posting, good info. I'm glad I changed mine at 34k and 7 yrs old . Went with synthetic for less friction and better range . Still waiting on that range thing.
If I am reading my report correctly, my old oil viscosity is much higher than the new stuff I replaced it with, especially given the temperature difference that the old stuff needed to be heated near the boiling point of water to be within the "recommended" range. The new stuff remains low even when not heated. I suspect that the gears in the Leaf will never reach the boiling point of water since it is not in an ICE engine, so anyone that does a replacement, make sure you get fully synesthetic that has a low viscosity even at low temperatures. The viscosity of my old oil at over 200F was 44, the new stuff I replaced it with is 5.91 at over 200F, 28.82 at 100F, so even cooler still has better viscosity than my old stuff. I suspect that is where I see the slight improvement in my range, which continues now that it has gotten much cooler outside. I haven't seen 80+ miles on the guess-o-meter in years. My actual real-world test of how much can I run it down to, I'm still getting +70 miles per charge when I use to only get lucky if I got 60 miles per charge.

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Re: How To: Reduction Gear Oil Change

Posted: Wed Oct 07, 2020 3:43 pm
by Steelcity
Knightmb, 84 miles!! Thats pretty impressive, my 11 bar leaf is 85 miles at 100%.

Re: How To: Reduction Gear Oil Change

Posted: Wed Oct 07, 2020 6:24 pm
by Nubo
knightmb wrote:
Wed Oct 07, 2020 7:07 am


If I am reading my report correctly, my old oil viscosity is much higher than the new stuff I replaced it with, especially given the temperature difference that the old stuff needed to be heated near the boiling point of water to be within the "recommended" range. ...
The two viscosity readings of the old fluid on the report were essentially at the same temperature (100c vs 210F) ; they're just two different ways of measuring.

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Re: How To: Reduction Gear Oil Change

Posted: Fri Oct 09, 2020 6:58 pm
by Oilpan4
knightmb wrote:
Wed Oct 07, 2020 7:07 am
Steelcity wrote:
Wed Oct 07, 2020 5:47 am
Knightmb & olipan4 thanks for posting, good info. I'm glad I changed mine at 34k and 7 yrs old . Went with synthetic for less friction and better range . Still waiting on that range thing.
If I am reading my report correctly, my old oil viscosity is much higher than the new stuff I replaced it with, especially given the temperature difference that the old stuff needed to be heated near the boiling point of water to be within the "recommended" range. The new stuff remains low even when not heated. I suspect that the gears in the Leaf will never reach the boiling point of water since it is not in an ICE engine, so anyone that does a replacement, make sure you get fully synesthetic that has a low viscosity even at low temperatures. The viscosity of my old oil at over 200F was 44, the new stuff I replaced it with is 5.91 at over 200F, 28.82 at 100F, so even cooler still has better viscosity than my old stuff. I suspect that is where I see the slight improvement in my range, which continues now that it has gotten much cooler outside. I haven't seen 80+ miles on the guess-o-meter in years. My actual real-world test of how much can I run it down to, I'm still getting +70 miles per charge when I use to only get lucky if I got 60 miles per charge.

Image
Where the gear teeth touch and metal to metal contact is made under heavy load the surface of the gears may reach 800 to 1,000F. That's the activation temperature of the ZDDP anti wear additive. When the heat and pressure breaks down the ZDDP it coats the gear teeth with zinc and protects the metal underneath. It's nano technology from the 1930s.
Too much heat and pressure blows right through the zinc coating, not enough heat and pressure and the ZDDP never activates.

Re: How To: Reduction Gear Oil Change

Posted: Sun Oct 18, 2020 4:46 pm
by bobkart
I'll be doing this oil change soon, and as I was looking the area over I saw what looks like a third drain plug:

Image

It's a bit left/below center in that picture, somewhat illuminated, at the top of the same housing that the other two plugs thread into.

I guess 'fill plug' would be a better term, assuming it goes to the same space as the other two plugs go to.

Before I open that one up and have a look, can anyone confirm or deny my hypothesis? It will be a lot easier to fill this gearbox back up with a vertically-oriented opening.

(But starting to doubt that this is the case as the service manual would surely use this one if it were an option.)