Diaqueen (now MZ320345) SAE90 LSD Oil Discussion

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I've seen this brought up here and there but I'd like to bring up a new discussion on it. evolutionm.net swears by this oil as the only oil to use in the t-case and rear differential. I've actually had a t-case go bad (not uncommon at all, especially at higher power levels) on my old evo while using amsoil severe gear 75w90. I don't attribute it to the failure, just a note, however:

Is there something special about this fluid? I've never been able to find any specs on it, other than it is SAE90 & GL5. However, it seems all SAE90 fluids run in the 13-24 range at 100c, and 600-700 at 40c.

Obviously, there is more to it than just viscosities, but here are a few examples of 75w90:

amsoil severe gear 75w90: 16.8 @ 100c, 109 @ 40c
motul gear 300 LS 75w90: 16.4 @ 100c, 109.6 @ 40c
redline 75w90: 16.1 @ 100c, 112 @ 40c

75w110:
amsoil severe gear 75w110:
redline 75w110: 20.9 @ 100c, 131 @ 40c

motul 90PA (not sure if this is sae90, doesn't seem to match specs): 14.5 @ 100c, 140 @ 40c, rated for GL4 as well as GL5.

Is there any reason why a 75w90 or 75w110 wouldn't work in place of the Diaqueen? Some special additive that isn't disclosed? The hearsay on evom is there have been a lot of failures on non-diaqueen fluids, but I'm not sure why that would be the case.
 
I too have read praise for the Diaqueen fluids on 3si.org. If you have any doubts,I'd just swing by a Mitsubushi dealership and buy some.
 
currently is what I'm using, I just don't understand why there's something so special about it. if any of the amsoils or redlines could provide the same protection at hot but flow better at cold, to me that'd be a lot more beneficial than diaqueen...
 
My uneducated guess would be that it's the same reason why a regular gear oil can roach certain clutch LSD's, or why the wrong trans fluid can cause torque converter clutch problems: Wrong or lacking friction modifiers for the application.

But again, just an uneducated guess.
 
Originally Posted By: DoubleWasp
My uneducated guess would be that it's the same reason why a regular gear oil can roach certain clutch LSD's, or why the wrong trans fluid can cause torque converter clutch problems: Wrong or lacking friction modifiers for the application.

But again, just an uneducated guess.


gotcha... well, I hope when RL says they're a replacement for diaqueen they mean it!
 
On a lighter note, that's one of the silliest names I've ever seen for a lube.
grin.gif
 
Originally Posted By: DoubleWasp
On a lighter note, that's one of the silliest names I've ever seen for a lube.
grin.gif



Molybdenum Dialkyl Dithiohosphate - it's in the Mitsi gear oils, hence the Dia prefix I presume. We try and use Mitsi products in all Mitsubishi's....but sometimes customers want cheap. Mitsubishi will honour warranties if you use their products, if you don't they won't at all.
 
interesting, first i've seen on anything regarding its make up. i assumed the dia started from diamond star motors
 
Only their trans oils are called Dia, engine oils, coolants, additives don't have it anywhere in the name. They have an engine additive based on Molybdenum Diakyl Dithiocarbamate (MoDTC)and it's just called Mitsubishi Engine Oil Treatment.
 
Originally Posted By: kyoo
currently is what I'm using, I just don't understand why there's something so special about it. if any of the amsoils or redlines could provide the same protection at hot but flow better at cold, to me that'd be a lot more beneficial than diaqueen...


Not quite true .... in terms of components durability.

That's where transmission power trains components ,especially differentials, of some Evolution owners 'could' fail prematurely ....
 
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In my car I have RP 75w90 in the rear differential and transfer case. I have about 45,000 miles.

Around 10,000 miles I swapped out the OEM fluid with VWB 80w90 and about 15,000 miles, the RP went in.

I have a hard time believing that the Diaqueen LS90 is anything special. Practically every other Japanese car that needed gear oil did fine when replacing the SAE90 with 80w90 conventional or 75w90 synthetic.
 
We're using Castrol 75w90 gl5 in all rear diffs and transfer cases. Not in limited slip diffs, there we use a Valvoline Synpower LS 75w90.

We only had issues with diffs or TC that didn't get serviced.
 
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thanks for all the inputs guys!

I think right now I'm looking at Redline Lightweight Shockproof to replace the diaqueen. I realize it's just a tagline, but protection of 75w140 while flowing like 80w sounds about exactly what I'm looking for.

My diff builder actually recommended 75w140, which is way too thick IMO considering I'm driving the car regularly, and on the way to and from events as well.

I was hoping to find a 75w90 that would provide enough protection over the SAE90, at least on a viscosity level, and shockproof sounds pretty good. From the other threads on BITOG I've found regarding shockproof though, sounds like it uses calcium, rather than the boron that's in Diaqueen, to protect against EP.

Any thoughts on that?
 
Originally Posted By: kyoo
I've seen this brought up here and there but I'd like to bring up a new discussion on it. evolutionm.net swears by this oil as the only oil to use in the t-case and rear differential. I've actually had a t-case go bad (not uncommon at all, especially at higher power levels) on my old evo while using amsoil severe gear 75w90. I don't attribute it to the failure, just a note, however:



The SAE90 spec'ed is NOT the same as 75W90 you'd used when your tcase gone bad.

At higher power levels ?? ...... surely you were not 'abusing and subject it to out of intended use' right?



Originally Posted By: kyoo
Is there something special about this fluid? I've never been able to find any specs on it, other than it is SAE90 & GL5. However, it seems all SAE90 fluids run in the 13-24 range at 100c, and 600-700 at 40c.



This fluid is nothing special ..... the difference is in KV@40*C/KV@100*C.

The pre-SAE J306 classification of SAE 90 was split into 2 categories as follows:

a )Current SAE '90' of KV@40*C of 135-165 cSt / KV@100*C of 13.5-18.5 cSt (AGMA 4EP /ISO150);and

b )Current SAE '110' of KV@40*C of 198-242 cSt / KV@100*C of 18.5-24.0 cSt (AGMA 5EP /ISO 220).

Similarly pre-SAE J306 SAE 140 has been split into current SAE '140' and SAE '190'.



Originally Posted By: kyoo
Obviously, there is more to it than just viscosities, but here are a few examples of 75w90:

amsoil severe gear 75w90: 16.8 @ 100c, 109 @ 40c
motul gear 300 LS 75w90: 16.4 @ 100c, 109.6 @ 40c
redline 75w90: 16.1 @ 100c, 112 @ 40c

75w110:
amsoil severe gear 75w110:
redline 75w110: 20.9 @ 100c, 131 @ 40c

motul 90PA (not sure if this is sae90, doesn't seem to match specs): 14.5 @ 100c, 140 @ 40c, rated for GL4 as well as GL5.



Only Motul 90PA from above numerically falls under SAE '90' -- AGMA 4EP /ISO 150 of KV@40*C of 135-165 cSt.

The rest is a grade lower. One may consider LE 1604/1605 too.

http://lubetechnologies.com/assets/1601-1610-product-info.pdf.



Originally Posted By: kyoo
Is there any reason why a 75w90 or 75w110 wouldn't work in place of the Diaqueen? Some special additive that isn't disclosed? The hearsay on evom is there have been a lot of failures on non-diaqueen fluids, but I'm not sure why that would be the case.



75W110 may work, if it's not subject to too high a power level utility.

Additives isn't an issue here.



Originally Posted By: kyoo
thanks for all the inputs guys!I think right now I'm looking at Redline Lightweight Shockproof to replace the diaqueen. I realize it's just a tagline, but protection of 75w140 while flowing like 80w sounds about exactly what I'm looking for.
My diff builder actually recommended 75w140, which is way too thick IMO considering I'm driving the car regularly, and on the way to and from events as well.
I was hoping to find a 75w90 that would provide enough protection over the SAE90, at least on a viscosity level, and shockproof sounds pretty good. From the other threads on BITOG I've found regarding shockproof though, sounds like it uses calcium, rather than the boron that's in Diaqueen, to protect against EP.
Any thoughts on that?


I'm with your diff builder.

Pick a 75W140 over Motul 90PA or 75W110 from above for components durability , and you may push your EVO to even higher level of power beyond what you'd done.

For your application ..... keep the 75W90 aside ... far far far away!

OP: You may keep the 75W90, but pleaseeeee...... drive it like a granny ...... if you know what I mean.
blush.gif
 
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you're pretty focused on the 40c temps - is there a reason that is more important than the 100c temps? I would otherwise assume thinner at cold is better, as it is still very thick. also keep in mind that's pretty much 100f, normal temps I drive will be at most 70f, and typically 50f or lower than that

I'm going to send blackstone some clean samples of diaqueen, svg gear, and redline 75w90 and see what the viscosities come out as. t-case I'm still leaning toward shockproof heavy, diff I'm still not sure. yes, when my t-case failed I happened to be using severe gear. after it was rebuilt, I was using severe gear, and no problems after inspection and much, much more racing.

again, autoxing, 1-2 road races/yr, etc. near-stock power levels. will keep looking into things. hard to imagine sae90 is still the best fluid, and that what makes it best is because it is thicker when cold?
 
Originally Posted By: kyoo
you're pretty focused on the 40c temps - is there a reason that is more important than the 100c temps? I would otherwise assume thinner at cold is better, as it is still very thick. also keep in mind that's pretty much 100f, normal temps I drive will be at most 70f, and typically 50f or lower than that


I'm inclined to agree -- why are we focusing so much on KV @ 40 C? It's only one piece of the puzzle here. Unless you have a sensor back there and know the oil is typically operating right at 40 C, that value is of very limited use.

You need to look at it as a whole, not just one number on a spec sheet.
 
Originally Posted By: dparm
Originally Posted By: kyoo
you're pretty focused on the 40c temps - is there a reason that is more important than the 100c temps? I would otherwise assume thinner at cold is better, as it is still very thick. also keep in mind that's pretty much 100f, normal temps I drive will be at most 70f, and typically 50f or lower than that


I'm inclined to agree -- why are we focusing so much on KV @ 40 C? It's only one piece of the puzzle here. Unless you have a sensor back there and know the oil is typically operating right at 40 C, that value is of very limited use.

You need to look at it as a whole, not just one number on a spec sheet.


dparm

thanks for the input - I THINK I watched your run on the autobahn not too long ago. i'll probably be there in July for an HPDE, but I think only the south course.

I'm going to send in some clean samples to blackstone to get some reads on the additives & viscosities at various heat temps, to see how these fluids behave.

I just want my drivetrain cool, protected, and happy, and I'd assume a lighter, high quality oil like redline or motul would do a better job than mitsu's sae90, but sounds like it's just plain hard to tell
 
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