80W90 Valvoline GL5 2000 Tundra 4X4

[INDYMAC]

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?

 

[Pablo]

Too few miles on the lube to comment, but it looked good so far.

The Honda comments seem a bit irrelevant because the VTF is something all together different and lighter than XW-90.

Also - where did you get those specs for XW-90's? They aren't correct.

 

[INDYMAC]

The 80W90 was in there for less than a year because I wanted to finally try some SAE 90 to see what happens. As you can tell, I am pleasantly surprised that the torque converter is finally smooth after all these years.

I used the VTF analogy to show that most dealerships don't have a clue when it comes to lubricants. That's the only relevancy.

The viscocity specs are probably not specs at all. Since they are a testing lab, they are probably just findings (universal averages) that Blackstone puts on their UOA reports. I will try to check to see if they are different from VOA findings on similar weights.

 

[Pablo]

This is kinda handy:

http://www.lubrizol.com/AutomotiveGearOil/j306_spec.asp

 

[INDYMAC]

Quote:

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This is kinda handy:

http://www.lubrizol.com/AutomotiveGearOil/j306_spec.asp

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This explains a lot about what Blackstone has found to be true and why the manufacturers specify SAE 90 for some differential applications where multi-vis 90W gear oils might fall short of equipment viscosity requirements. Thanks Pablo.

 

[Jasper8146]

I just wanted to say I had 2 different Lexus SC 400's over a 10 year period and remember the differential spec being SAE 90 and wondering why they seemed to be so adamant about it in the manual and yet the dealer didn't have any and only used Quaker State conventional 80w-90 unless the customer supplied something else. I never tried the straight 90 because it was never available and I thought it was too heavy anyway. I always ran a synthetic 75w-90 either redline or Mobil 1. Well, between the two cars, I actually blew 3 differentials and none of it was possibly due to abuse given the way I drive. Your thread makes me wonder if they would have blown anyway had I gone to the trouble of getting SAE 90 or would they have run smoother? Until your post here, I had never even considered whether the lighter synthetic fluid might have caused my problems. Glad you posted.

 

[Bror Jace]

Interesting Jasper8146, but I am reluctant to blame any gear oil under almost any circumstances for a blown differential. Excessive wear? OK. Howling at speed? OK. ... but blown up as in shrapnel wear gears should be? Sounds to me like the diff is/was under-engineered for the application.

As for the weights, 75W-90 and 80W-90 and straight 90 should all be the same thickness at operating temp. Yes, the multi-viscosity oils are prone to shearing ... but I have a hard time believeing that was the case here.