'92 Legacy, 6,500 miles on a cocktail ("USC")

[bluesubie]

This is not my uoa.

It was posted on nasioc and is a very popular cocktail used by folks looking for the right combination of friction for the synchros and protection for the gears (hopefully). It is known in the Subaru community as "Uncle Scotty's Cocktail" and I know that there have been people here that have tried it.

I've never used it because I only use GL5 gear oils and have never mixed different brands. Given the mileage, I would guess that the high iron is due to the age of the car but it's hard to tell without a comparison. There will be a WRX uoa on it soon.
Do you see many uoa/voa's here with this amount of calcium, moly and magnesium?

Would appreciate some comments!! Anyone think that a thicker viscosity oil would be more appropriate for this car? Or maybe a GL5?

Unviversal averages in parentheses:

Equipment make: Subaru
Equipment model: Legacy
Oil use interval: 6,500
Make-up oil: 0
Oil type & Grade:
1.0 qt. Redline Shockproof Heavyweight
1.0 qt. Pennzoil Synchromesh
1.7 qt. Castrol Hypoy C 80W90

Miles on unit: 264,191

Aluminum 10 (13)
Chromium 1 (2)
Iron 90 (107)
Copper 7 (26)
Lead 0 (15)
Tin 0 (1)
Molybdenum 1228 (14)
Nickel 0 (1)
Maganese 2 (4)
Silver 0 (0)
Titanium 1 (0)
Potassium 1 (1)
Boron 147 (151)
Silicon 43 (38)
Sodium 24 (5)
Calcium 10900 (257)
Magnesium 1453 (4)
Phosphorous 1384 (1533)
Zinc 310 (413)
Barium 0 (11)

Properties
cStViscosity @ 100C: 13.78
Fuel: -
Antifreeze: -
Flashpoint: 395F
Water: 0
Insolubles: .8

Thanks for the note. This is an interesting mix of oil here, in Uncle Scotty’s Cocktail. Is it corrosive? Well, we didn’t find anything in this sample that would indicate it’s corrosive, though if you wanted to do a TAN test, that would tell you how acidic it is. Iron read high, when you consider that averages are based on 33,000 miles on the oil and this oil was run 6,500. We don’t know where the metals stood before this – whether they’re getting worse or better. Iron is the only thing reading out of line.

-Dennis

 

[SubLGT]

My guess: there is elevated ring and pinion wear because of lowered concentration of EP additives.

 

[MolaKule]

The EP additives are fine, but the Moly is not needed in a manual transmission fluid, the Calcium is way too high, and it would be helpful to see how much sulfur is produced by this mix.

I suspect the sulfur and moly contributed to high wear for this short a period.

I would retire Uncle Scotty and and his mix.

 

[SubLGT]

Originally Posted By: MolaKule
.......... I suspect the sulfur and moly contributed to high wear for this short a period...........


Interesting. Do sulfur and moly create high wear by corrosion? By interfering with other additives? Inquiring minds want to know.

 

[MolaKule]

The sulfur could be contributing to Fe corrosion and bearing wear, and the disulfide in the moly disulfide simply adds to the sulfur concentration.

The moly contributes nothing to synchro engagement and actually interferes with the synchro friction modifier.

The magnesium is low but the viscosity is about right.

A VOA of this mix (with sulfur concentraion and TAN stated) would be very interesting.

 

[bluesubie]

Thanks, Sub and Mola.

Does Blackstone measure sulfur?

-Dennis

 

[SubLGT]

Originally Posted By: bluesubie
Thanks, Sub and Mola.

Does Blackstone measure sulfur?

-Dennis


Yes, for $40.00 extra

 

[SubLGT]

I see that the VOA on the "cocktail" has been completed, by Blackstone.

100 degC vis= 11.79, which makes it a SAE85 (SAE J306 specs)

Sulfur= 1.73%

Moly= 182 ppm

TAN= 2.4

TBN= 0.1


http://forums.nasioc.com/forums/showthread.php?t=1489327&page=2

 

[bluesubie]

Mola? Hello?

-Dennis

 

[SubLGT]

Originally Posted By: MolaKule
..................

The moly contributes nothing to synchro engagement and actually interferes with the synchro friction modifier...........


Motul 300 Gear 75W90 contains 767 ppm moly, according to this VOA:

https://bobistheoilguy.com/forums/threads/motul-300-gear-75w90-voa.89351/

Bluesubie, isn't the Motul 300 popular with WRX owners?

 

[SubLGT]

Originally Posted By: SubLGT

..................

The moly contributes nothing to synchro engagement and actually interferes with the synchro friction modifier...........


Motul 300 Gear 75W90 contains 767 ppm moly, according to this VOA:

https://bobistheoilguy.com/forums/threads/motul-300-gear-75w90-voa.89351/

But an earlier VOA from 2006 shows zero moly.

http://www.bobistheoilguy.com/forums/ubb...true#Post706793

The Motul 300 gets good reviews from some Subaru STI owners on IWSTI.com, and lackluster reviews from others, regarding synchro action.

 

[Bror Jace]

bluesubie, as Mola and others have chimed in, this was an interesting ... but not terribly successful experiment. These formulations are more complicated than the handful of elements on a $20 UOA will show. That leads us to guessing what's going in here.

Speaking of which, I vote for little or no corrosion taking place ... as the first thing I'd think you'd see is a spike in copper ... and then tin, at 20% of your copper value.

I'd use Red Line MT-90 or Amsoil MTG as solid, reliable performers in this application (90 weight syncromesh fluids) and be done with it. Of course Motul makes some good lubricants so I wouldn't hesitate to use their GL4/5 90 weight gear oil as well.

A UOA using any one of these three should be a serious improvement over what you have right now.

Tell 'Scotty' he needs to go back to engineering and dream up somethin' else.

 

[bluesubie]

Sub - Yes, the Motul Gear 300 is getting more and more popular on nasioc as well. One of the tuners there that rebuilds lots of tranny's is now recommending a blend of Gear 300 and something else (one of the Redline's maybe?) and seeing so many trashed tranny's from USC.

I tried Gear 300 in my '03 WRX and liked it at first, but it felt notchy the more mileage on it. The Amsoil Severe Gear is feeling better after 12k than it did the first 10k.

10 years of driving Subaru 5mt's and I've never mixed any gear oil.

Bror - Great points although Subaru's do call for GL-5. I know it's hard to tell from the cocktail.

-Dennis

 

[SubLGT]

Originally Posted By: Bror Jace
..................

I'd use Red Line MT-90 or Amsoil MTG as solid, reliable performers in this application (90 weight syncromesh fluids) and be done with it................


These oils would certainly ease up the synchro action in the Subaru transmission, especially at sub freezing temps, but they would also eat up the ring & pinion gear set that comprises the front differential inside the transmission.