UOA: 02 WRX 5MT, 40K - Valvoline "cocktail" 80w90

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1,225
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SW Michigan
Got my 02 WRX with 109K on the clock. Previous owner, always took it to the dealer, and their fluids of choice were standard Valvoline oils. In the colder MI winter months it was really sluggish and hard to get into gear until warm. I tried full synthetic, and cold shifting was improved, but that darn first gear was still PITA to get into rolling, and it would grind sometimes. Swapped it out for Valvoline Synthetic Blend 80w90, and cold shifting was good as synthetic but the first gear issue still there. Read about the NASIOC "Cocktail Mix", but couldn't source anything but the syncromesh locally. So I armed myself with what I had on hand. 1.5 quarts of 80w90 Valvoline Conventional, 1.5 quarts of 80w90 Valvoline Synthetic Blend, and .7-1quart of Pennzoil Synromesh. Cold shifting was vastly improved. Getting into first gear from a roll greatly improved as well. I get the occasional notch feeling when doing it, but I don't often go into first from a roll. I probably ran it longer than I should have (40K), but I have no complaints with this cocktail mix. Blackstone did say the iron was a little high, but seems within what others were getting on NASIOC with original cocktail mix. I have missed a gear or let out too soon on occasion, so that would have caused some unintended wear shocked
 
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upstate NY
I think you've got a winning brew there! You have double the miles of the universal averages and still have great wear numbers. I see that the viscosity numbers are low for the 80w90 grade but nice results just the same.
 
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2,358
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Paradise of Florida
Too thin. I'd stick with a full synth non-lsd gear oil from Redline, Torco, Motul, Ford, Eneos, Subaru, Idemitsu... and enjoy a protected transmission that might need a little warm up. Drain plug magnet?
 

Buffman

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SW Michigan
Originally Posted By: Greasymechtech
Too thin. I'd stick with a full synth non-lsd gear oil from Redline, Torco, Motul, Ford, Eneos, Subaru, Idemitsu... and enjoy a protected transmission that might need a little warm up. Drain plug magnet?
Greasy, From everything I've read, Subaru 5MT transmissions do not like full synthetic oils, specifically the synchros. I experienced such with the Valvoline Full Synthetic, but perhaps something like Mobil Delvac™ Synthetic may be different. I would imagine the reduced viscosity is from the full quart of synchromesh. Yes drain plug magnet. Had the normal black sludge on it. Nothing major, no shiny pieces.
 

MolaKule

Staff member
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21,909
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Iowegia - USA
Quote:
From everything I've read, Subaru 5MT transmissions do not like full synthetic oils, specifically the synchros. I experienced such with the Valvoline Full Synthetic, but perhaps something like Mobil Delvac™ Synthetic may be different.
Have you tried something like Redline MT-90 or Amsoil MTG? Those would be 75W90s. The synchros don't know what the base oil is, they primarily care about the friction modifier, which is why you saw improved shifting when you added the Pennzoil Synchromesh. The Valvoline Full Synthetic differential lube does not have the friction modifier needed for the synchronizer assembly which is why it performed so poorly.
 

Buffman

Thread starter
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1,225
Location
SW Michigan
Originally Posted By: MolaKule
Quote:
From everything I've read, Subaru 5MT transmissions do not like full synthetic oils, specifically the synchros. I experienced such with the Valvoline Full Synthetic, but perhaps something like Mobil Delvac™ Synthetic may be different.
Have you tried something like Redline MT-90 or Amsoil MTG? Those would be 75W90s. The synchros don't know what the base oil is, they primarily care about the friction modifier, which is why you saw improved shifting when you added the Pennzoil Synchromesh. The Valvoline Full Synthetic differential lube does not have the friction modifier needed for the synchronizer assembly which is why it performed so poorly.
I believe the semi-synthetic, and full synthetic Valvoline both contain LSD friction modifiers?
 

MolaKule

Staff member
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21,909
Location
Iowegia - USA
Originally Posted By: Buffman
Originally Posted By: MolaKule
Quote:
From everything I've read, Subaru 5MT transmissions do not like full synthetic oils, specifically the synchros. I experienced such with the Valvoline Full Synthetic, but perhaps something like Mobil Delvac™ Synthetic may be different.
Have you tried something like Redline MT-90 or Amsoil MTG? Those would be 75W90s. The synchros don't know what the base oil is, they primarily care about the friction modifier, which is why you saw improved shifting when you added the Pennzoil Synchromesh. The Valvoline Full Synthetic differential lube does not have the friction modifier needed for the synchronizer assembly which is why it performed so poorly.
I believe the semi-synthetic, and full synthetic Valvoline both contain LSD friction modifiers?
Differential fluid friction modifiers are NOT the same chemistry as the friction modifiers in MTL's, so you cannot equate the two. Manual Transmission Technology and Lubricants
 
Last edited:

Buffman

Thread starter
Messages
1,225
Location
SW Michigan
Originally Posted By: MolaKule
Originally Posted By: Buffman
Originally Posted By: MolaKule
Quote:
From everything I've read, Subaru 5MT transmissions do not like full synthetic oils, specifically the synchros. I experienced such with the Valvoline Full Synthetic, but perhaps something like Mobil Delvac™ Synthetic may be different.
Have you tried something like Redline MT-90 or Amsoil MTG? Those would be 75W90s. The synchros don't know what the base oil is, they primarily care about the friction modifier, which is why you saw improved shifting when you added the Pennzoil Synchromesh. The Valvoline Full Synthetic differential lube does not have the friction modifier needed for the synchronizer assembly which is why it performed so poorly.
I believe the semi-synthetic, and full synthetic Valvoline both contain LSD friction modifiers?
Differential fluid friction modifiers are NOT the same chemistry as the friction modifiers in MTL's, so you cannot equate the two. Manual Transmission Technology and Lubricants
Thanks Mola. Most of what's recommended in that thread is for GL4 spec'd transmissions. The 5MT in the WRX, specs GL5, I believe because of the unique drivetrain.
 
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MolaKule

Staff member
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Does it have a common sump for the differential AND the transmission? If this subie has the common sump for the hypoid differential AND the transmission then it does needs a 75W90 GL-5 synchromesh fluid.
 
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2,358
Location
Paradise of Florida
What you experienced with the Valvoline full synth is the lsd additive. If you want to thin out whatever NON-LSD 75w90 gear oil that you found, use Lubegard supplement. copy/paste is link don't work. http://www.lubegard.com/~/C-269/LUBEGARD+Gear+Fluid+Supplement
 

Buffman

Thread starter
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1,225
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SW Michigan
Originally Posted By: MolaKule
Does it have a common sump for the differential AND the transmission? If this subie has the common sump for the hypoid differential AND the transmission then it does needs a 75W90 GL-5 synchromesh fluid.
Yeah the front diff and trans share a common sump.
 

Buffman

Thread starter
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1,225
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SW Michigan
Originally Posted By: Pablo
For Subaru MT's with shared front differential requiring GL-5, the solution is easy. Amsoil SVT 75W-110 I know my 2014 is slightly different, but after 2000 or so miles the stock fluid shifted like grit. The SVT is like butter.
may have to give it a try. Although I think after 2006 they changed the internals a bit to help with some of the quirks the older 5MTs had.
 
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22,188
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Colorado Springs
Originally Posted By: Greasymechtech
What you experienced with the Valvoline full synth is the lsd additive. If you want to thin out whatever NON-LSD 75w90 gear oil that you found, use Lubegard supplement. copy/paste is link don't work. http://www.lubegard.com/~/C-269/LUBEGARD+Gear+Fluid+Supplement
I agree on both points. All Valvoline gear oils now contain LSD additive, which is a shame because prior to that, I had successfully used their GL-5 products in my Corolla manual transaxle. in fact, the conventional 75w-90 high performance gear oil was the best shifting fluid I've used until they added the LSD additive. I also use Lubegard gear fluid supplement in mine and it noticeably helps cold weather shifting and shifting in general. It's now almost impossible to find a conventional GL-5 product without LSD additive. In fact, the only one I know of is Coastal.
 
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