Re: How To: Reduction Gear Oil Change
Posted: Tue Oct 06, 2020 7:50 pm
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.
The forum for all aspects of the Nissan Leaf
https://mynissanleaf.com/
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."
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.
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.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. ...
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.knightmb wrote: ↑Wed Oct 07, 2020 7:07 amIf 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.
![]()