This sample of Valvoline High Performance GL5 Gear Lube SAE 80W90 (mineral based) was taken from a 2000 Toyota Tundra SR5 TRD 4X4 rear differential (no LSD) on a recent drain and fill. The truck has 128,042 miles on it. The gear lube was in use for 13,067 miles. The only extreme use this truck sees (if you could call it that) is a lot of mud driving during hunting season. I do not toe anything with it. The coldest temperature it saw this winter was 8degF. Toyota specifically states to use SAE 90 hypoid type GL5 gear oil. If temperatures are expected to be below 0degF, 80W90 GL5 should be used. This rear differential has never seen SAE 90 GL5 in 128K miles (maybe the factory fill was SAE 90). It's been on a steady diet of various 75W90 and 80W90 gear oils until the new fill, LE 607. I will give you my impression of LE 607 after the report:
Blackstone Labs
Element/80W90 Valvo/Universal Averages
Aluminum/0/2
Chromium/0/1
Iron/47/106
Copper/0/31
Lead/1/4
Tin/0/0
Moly/0/34
Nickel/0/1
Manganese/0/2
Silver/0/0
Titanium/0/0
Potassium/0/1
Boron/215/70
Silicon/2/16
Sodium/0/6
Calcium/19/149
Magnesium/5/6
Phosphorus/1364/657
Zinc/11/144
Barium/0/2
SUS@210F/75.7/68-82
Flashpoint/420F/>405
Water%/0.0/ Insolubles%/0.1/
Blackstone's comments:
JACK: We didn't find any problems in this sample of gear oil. Iron was the only metal to show up at a
significant level, and it's still lower than universal averages show is typical of a gear box. No moisture or
other contaminants were present, and the insolubles level (solids due to oil oxidation and heat) was low
at 0.1%. The viscosity was normal for an 80W/90 oil. You can run the next oil in this gear box longer than
13,000 miles -- we'd give it 20K miles before changing it.
My comments:
As I mentioned before, this differential has seen only 75W90 and 80W90 gear oil over the years and as you can see, the UOA of this sample is hard to find fault with. Like several other Toyota owners, I've always wondered why the owners manual is so specific about using SAE 90 while they don't even carry it in their dealerships. Honda has the same problem with the S2000. That manual states SAE 90 only, no exceptions. Yet Honda dealers don't carry SAE 90 either, nor do they know much about the S2000. Many try to put the CRV diff fluid in the S2000 and the diff is destroyed within hours. Well, not to get off topic too much and make a long story even longer, I've decided to try a straight mineral based SAE 90 this time. LE 607 is now in the pumpkin. I didn't expect to notice any difference because I didn't think there was anything wrong with my diff. But I did notice something different. My transmission is a 3 speed mechanical automatic with an electronic 4th gear (overdrive). It has often upshifted hard into 3rd gear when you let off on the accelerator after pushing it somewhat hard from 2nd gear (in Drive). I always attributed this phenomenom to a funky torgue converter locking hard instead of smoothly when I let off the gas a little. I have not been able to duplicate this since filling the diff with LE 607. That's the only thing I've noticed, and I didn't expect this phenomenom to be related to the differential oil weight. But it may be so. Thoughts?
For comparative purposes:
SUS viscosity @ 210F for 75W90 gear oil should be 67-80. Redline 75W90 tests at 83.7.
SUS viscosity @ 210F for 80W90 gear oil should be 68-82.
Valvoline 80W90 tests at 75.7.
SUS viscosity @ 210F for SAE 90 gear oil should be 85-105.
LE 607 SAE 90 tests at 89.4 and 93.4.
I respectfully submit that there is a difference in viscosity at high temps between multi-vis 90 wt gear oils and straight SAE 90 gear oils. Maybe the manufacturers do know something us internet Tribologist wannabe's don't?
Blackstone Labs
Element/80W90 Valvo/Universal Averages
Aluminum/0/2
Chromium/0/1
Iron/47/106
Copper/0/31
Lead/1/4
Tin/0/0
Moly/0/34
Nickel/0/1
Manganese/0/2
Silver/0/0
Titanium/0/0
Potassium/0/1
Boron/215/70
Silicon/2/16
Sodium/0/6
Calcium/19/149
Magnesium/5/6
Phosphorus/1364/657
Zinc/11/144
Barium/0/2
SUS@210F/75.7/68-82
Flashpoint/420F/>405
Water%/0.0/ Insolubles%/0.1/
Blackstone's comments:
JACK: We didn't find any problems in this sample of gear oil. Iron was the only metal to show up at a
significant level, and it's still lower than universal averages show is typical of a gear box. No moisture or
other contaminants were present, and the insolubles level (solids due to oil oxidation and heat) was low
at 0.1%. The viscosity was normal for an 80W/90 oil. You can run the next oil in this gear box longer than
13,000 miles -- we'd give it 20K miles before changing it.
My comments:
As I mentioned before, this differential has seen only 75W90 and 80W90 gear oil over the years and as you can see, the UOA of this sample is hard to find fault with. Like several other Toyota owners, I've always wondered why the owners manual is so specific about using SAE 90 while they don't even carry it in their dealerships. Honda has the same problem with the S2000. That manual states SAE 90 only, no exceptions. Yet Honda dealers don't carry SAE 90 either, nor do they know much about the S2000. Many try to put the CRV diff fluid in the S2000 and the diff is destroyed within hours. Well, not to get off topic too much and make a long story even longer, I've decided to try a straight mineral based SAE 90 this time. LE 607 is now in the pumpkin. I didn't expect to notice any difference because I didn't think there was anything wrong with my diff. But I did notice something different. My transmission is a 3 speed mechanical automatic with an electronic 4th gear (overdrive). It has often upshifted hard into 3rd gear when you let off on the accelerator after pushing it somewhat hard from 2nd gear (in Drive). I always attributed this phenomenom to a funky torgue converter locking hard instead of smoothly when I let off the gas a little. I have not been able to duplicate this since filling the diff with LE 607. That's the only thing I've noticed, and I didn't expect this phenomenom to be related to the differential oil weight. But it may be so. Thoughts?
For comparative purposes:
SUS viscosity @ 210F for 75W90 gear oil should be 67-80. Redline 75W90 tests at 83.7.
SUS viscosity @ 210F for 80W90 gear oil should be 68-82.
Valvoline 80W90 tests at 75.7.
SUS viscosity @ 210F for SAE 90 gear oil should be 85-105.
LE 607 SAE 90 tests at 89.4 and 93.4.
I respectfully submit that there is a difference in viscosity at high temps between multi-vis 90 wt gear oils and straight SAE 90 gear oils. Maybe the manufacturers do know something us internet Tribologist wannabe's don't?
