Amsoil 75W-140, 2003 Honda S2000 rear diff, 6K kms

[INDYMAC]

This is a friends S2000 with a stock Torsen LSD. He had 100K kms on the unit at the time, and 6000 kms on the gear oil. His previous fill was Amsoil 75W-110, but the sample got lost in the mail. Honda recommends SAE 90 GL5 or 6 for this unit. It holds 0.81 qts of fluid.

Toromont Cat Fluids Lab

Fe 297
Cr 5
Mo 2
Al 0
Cu 1
Pb 0
Si 0
Ti 12
Ni 10
Ag 0
Si 6
Na 3
K 2
Zn 4
Mg 0
P 740
Ba 1
kV cSt @100C 17.90
Anti-freeze neg
Fuel neg
Water neg

 

[Johnny2Bad]

Honda sources the rear diff in the S2000 from Mazda; same unit as found in IRS Mazda Miata, RX-7, RX-8 (although the half shafts are a bit beefier in the S2000 application).

 

[INDYMAC]

Originally Posted By: Johnny2Bad
Honda sources the rear diff in the S2000 from Mazda; same unit as found in IRS Mazda Miata, RX-7, RX-8 (although the half shafts are a bit beefier in the S2000 application).


Where did you get this information? I heard a few years ago that it was a KIA 4.10 gear set. I'm not sure about the Torsen LSD though.

 

[MolaKule]

This is not too bad for 6k km and an 18 cSt GL.

Fe 297, Cr 5, Ti 12, Ni 10 are usually alloying components of steel and this indicates some wear is occurring.

 

[NorWest5]

Curious as to why 75W-90 Mobil1 synthetic was not used in the S2000's diff fluid change as Honda requirement for this vehicle was and is 90W diff fluid?

 

[INDYMAC]

Originally Posted By: NorWest5
Curious as to why 75W-90 Mobil1 synthetic was not used in the S2000's diff fluid change as Honda requirement for this vehicle was and is 90W diff fluid?


The proper viscosity was SAE 90 GL5 or 6. It is now SAE 110. Do not use 75W-90. If you live in Canada, you are allowed to use 80W-90 in the winter.

 

[HTSS_TR]

I currently have M1 75W-90 in my S2000 along with Honda MTF, are you sure that Honda update the diff fluid to 75W-110 now ?

Other S2000 owners use these fluids:

Red Line Shock Proof 75w90
Amsoil Severe Gear 75w-90, 75w-110
Royal Purple 75w-90
Motul 90 PA
LE 1605

Amsoil website:
Differential, Rear......GL-5
All TEMPS......90
SEVERE GEAR 75W-90 Synthetic EP Lubricant (SVGQT)
75W-90 Synthetic Long Life Gear Lube (FGRQT)
SEVERE GEAR 75W-110 Synthetic EP Lubricant (SVTQT)
SAE 80W-90 Synthetic Gear Lube (AGLQT)

 

[INDYMAC]

the s2000 diff graveyard is littered with 75w-90 users. not so with pre j306 sae 90 or post j306 sae 110 users. that's about all i have to offer on the subject of viscosity choices. as far a brand formula products go, there is none better for protction than le 1605.

 

[Bror Jace]

INDYMAC, my gut tells me this is high (nearly 300ppm in 6000kms - not miles) but I don't have a reference point anywhere. I would have expected a value under 100 ppm ... but maybe that's not realistic for a Torsen LSD.

"the S2000 diff graveyard is littered with 75w-90 users."

I'm using Chevron Delo ESI 80W-90 right now. I changed out the factory oil at 15,000 miles and added this stuff. I dumped it 3,000 miles later and refilled with the same. I'd like to put 10,000 miles on the 2bd fill before I drain it again and have the sample tested. At the rate I put miles on this car, that will be at the end of next year.

Even if it is a poor choice, I can't do too much harm in 13,000 miles.

 

[sprintman]

Originally Posted By: INDYMAC
the s2000 diff graveyard is littered with 75w-90 users. not so with pre j306 sae 90 or post j306 sae 110 users. that's about all i have to offer on the subject of viscosity choices. as far a brand formula products go, there is none better for protction than le 1605.


What's your opinion on 75W90 syn in general? I'm running 75W140 Redline in a newish 4-pinion LSD, but considering replacing it completely in 5,000 kms with say
Amsoil SVG 75W90, or half of it with RL 75W90 to get a rough 75W110.

 

[INDYMAC]

Originally Posted By: sprintman
Originally Posted By: INDYMAC
the s2000 diff graveyard is littered with 75w-90 users. not so with pre j306 sae 90 or post j306 sae 110 users. that's about all i have to offer on the subject of viscosity choices. as far a brand formula products go, there is none better for protction than le 1605.


What's your opinion on 75W90 syn in general? I'm running 75W140 Redline in a newish 4-pinion LSD, but considering replacing it completely in 5,000 kms with say
Amsoil SVG 75W90, or half of it with RL 75W90 to get a rough 75W110.


I like SAE 110 for rear, and 75w-90 in t-case and front diff. Conventional or synthetic doesn't matter to me, as long as it performs well.

Why not use Amsoil 75w-110 SVT? I've seen a decent UOA of that in an S2000 recently.

 

[sprintman]

Originally Posted By: INDYMAC
Originally Posted By: sprintman
Originally Posted By: INDYMAC
the s2000 diff graveyard is littered with 75w-90 users. not so with pre j306 sae 90 or post j306 sae 110 users. that's about all i have to offer on the subject of viscosity choices. as far a brand formula products go, there is none better for protction than le 1605.


What's your opinion on 75W90 syn in general? I'm running 75W140 Redline in a newish 4-pinion LSD, but considering replacing it completely in 5,000 kms with say
Amsoil SVG 75W90, or half of it with RL 75W90 to get a rough 75W110.


I like SAE 110 for rear, and 75w-90 in t-case and front diff. Conventional or synthetic doesn't matter to me, as long as it performs well.

Why not use Amsoil 75w-110 SVT? I've seen a decent UOA of that in an S2000 recently.

Not for an S2000 but I'll look for it. Amsoil isn't readily available unfortunately

 

[INDYMAC]

Amsoil in Ausralia
http://www.alphalubrication.com/

LE in Australia
http://www.lubeng.com.au/

 

[sprintman]

Originally Posted By: INDYMAC
Amsoil in Ausralia
http://www.alphalubrication.com/

LE in Australia
http://www.lubeng.com.au/


Know both but freight kills it. At least Redline is available locally

 

[INDYMAC]

I sent my friend a couple of quarts of Doulec LE 1605 to try. He ran it for 2 seasons and 9K kms. Here's the rsults from the first fill (Toromont LABS again):

109000 kms on equipment
Iron 56
Cromium 1
Molybdenum 1
Aluminum 1
Copper 0
Lead 0
Tin 0
Titanium 3
Nickel 3
Silver 0
Silicon 8
Sodium 3
Potassium 1
Zinc 31
Magnesium 0
Phosphorus 1210
Barium 1
Boron 66
Calcium 62
Manganese 2
Vanadium 0
cSt@100C 18.53
Water Negative

He says he wants to keep using this gear oil but doesn't have a source in Canada. Any help there? He lives near Toronto.

 

[INDYMAC]

Here is a link to another forum discussion about his LE 1605 UOA:

http://www.s2ki.com/s2000/topic/1058208-...-le1605-sae110/

 

[sprintman]

Originally Posted By: INDYMAC
the s2000 diff graveyard is littered with 75w-90 users. not so with pre j306 sae 90 or post j306 sae 110 users. that's about all i have to offer on the subject of viscosity choices. as far a brand formula products go, there is none better for protction than le 1605.

Why?

 

[INDYMAC]

Not sure why. But it's been obvious to me while following the issue for over 10 years. SAE 75W-90 was not the same viscosity as SAE 90 pre-J306, nor is it the same as SAE 110 post-J306.

Sometime in the early 2000's, Honda of Canada authorized 80W-90 GL5 during the winter months though.

 

[tudorart]

Originally Posted By: INDYMAC
Originally Posted By: Johnny2Bad
Honda sources the rear diff in the S2000 from Mazda; same unit as found in IRS Mazda Miata, RX-7, RX-8 (although the half shafts are a bit beefier in the S2000 application).


Where did you get this information? I heard a few years ago that it was a KIA 4.10 gear set. I'm not sure about the Torsen LSD though.


Here's what I know:
I can confirm the Kia match (sportage 4x4)on the pinion/ring. I bought my 4.7 set from a Kia dealer after researching autotrader for a VIN to provide them. The mazda rx8 or miata (don't remember) that had this torsen I believe has it specd with 75W140.
I can also say the the tranny was simillar or same as RX-8 and IS lexus if not mistaken and they had 75W90 GL4 specd.

The lube is indeed an issue. As this is a convertable driven in warm climate and also a low torque at low rpm, they wanted the thinnest but at the same time polymer free fluid for the diff to cut losses as 20% is about what you see on this car.
That would give out the most power at that level of viscosity protection which is about the same with base oil viscosity => a lot of film.

So off course any 75W90 would be short in viscosity protection.

First because the high VI would make them a lot thinner at true operating temps.
Second because most if not all 75W90 are syntehtics of group api 3 or 4 which both have less film under pressure compared to a mineral or ester, not to mention they likely also have polymers that give out even more.
Third what's been said. J306 changed and the upper part of the 90 is now cut and relabeled 110. In the past most fluids in that upper part of the 90 were sae90 monogrades GL5 and GL6 for heavy duty.

The recommended multigrade oil for this diff is at the very minimum a 75W110.
As far as monogrades, SAE90 is ok but must be petrol based/low VI, min.16-18.5cSt/close to 110, GL-5+LS ready.

They did a similar thing with the engine oil to maximize output but at least in Europe they also approve 5W40 (besides the 10W30). It should give out more losses, similar or better base oil protection after permanent and temporary shear (at 9k rpm) but more winter capability. Note, no 5W30 is listed ... anywhere. Not to say none of the 5W30's are incompatible, but they do seem consistent in their philosophy to avoid thin base stocks and polymers.