simons

Thanks for all replies!
What I understand from all the answers so far is that nobody that answered ever had a problem with their diff regardless of the used oil. Which suggests its doesnt really matter if you use 80w90, 75w110, 75w140 or anywhere in between.

I honestly have to say my diff oil hasnt been changed in 8 years (40k kms). I hope there's no damage. No strange sounds. Seems to work fine.

Dont know what oil is in it. From a dealer.

Basically still doubting between the 80w90 or 85w140 both mineral (110 not easily availabe).

There seems to be no agreement on what is best...

Btw, its a dd driver. Run vtec whenever driven. Sporadic drift.

simons

If anybody knows that the effect is of a thicker oil (..w140) vs thinner (...w90) with regards to the functioning of the diff and possibly different traction outcomes to the Torsen LSD function, I would be interested to learn!

I honestly have no idea how much the actual difference is between ..w90 and ..w140 in the real world. Anybody does know? It sounds like a huge gap. But perhaps the numbers dont reflect absolut thinkness numbers?

Chuck S

Ignoring scheduled maintenance has a nasty habit of biting hard.

The normal service maintenance schedule calls for the the differential oil to be changed every two years or 30,000 miles/48,000 km (whichever comes first). Severe service schedule is half that mileage/time. Changing the differential oil is no harder than changing the gearbox oil. $25 and an hour of your time.

The paramount criteria is to use "an SAE 90 viscosity hypoid gear oil, API service classified GL5 or GL6 only." (Honda owners manual.) The SAE 90 viscosity spec changed since our cars were build and the "new SAE 110" meets the same spec. Multigrade oils are neither thicker nor thinner than their single grade counterparts but have the corresponding lubrication in a range of temperatures. Note these are multigrade, not multhickness nor multiweight.

Any proper grade GL5 or GL6 meets spec and multigrades provide stable lubrication in a wider range of temperatures than single grade. Am$oil gives some of us warm fuzzy feelings and I have a bottle of differential oil sitting in a cabinet in case I can no longer fine LE-1605 (which makes me feel warm and cuddly).

-- Chuck

Jub

AmsOil 75w140. Unless someone has solid data to back up why they use what they use, it's a pretty useless guess. I picked what I perceived as the highest quality diff oil that I could get at my local store and feel good that 140 is higher than 110. Theoretically, it should have a higher heat tolerance and I autocross my car. So far, so good. I doubt my use of AmsOil 75w140 significantly changes my risk of breaking parts as opposed to someone using Mobil1 75w110.

I am curious if the fluid has any effect on the LSD behavior but I don't believe so in a torsen since it's all gear driven.

Slowcrash_101

Torsen LSD has slightly less locking the thicker the fluid, it's not enough for you to notice.

75w-140 here 4 years on, change every 20k miles, comes out clean.

jackmugen02

What I use and what Puddymod recommended 75W140(I use Amsoil).

simons

okay, so I have to choose between 80w90 or 85w140. No amsoil available here. Both oils are mineral hypoid. No limited slip. Just regular gear oil.

I have no idea what the difference to the diff would be. And if I would be able to feel it?

The local honda service dealer drops in 80w90. But perhaps thats just what they have available.

please advice! Thanks again

alSpeed2k

Where are you located?

flanders

Why would you not use a synthetic?

Opie Oils

Hi,

75w-90 and 75w-140 are the same viscosity when cold, the only difference is when hot and the viscosity of the SAE140 is thicker than the SAE90. How this effects the way the diff performs in theory is the thinner the oil the more aggressive the lsd becomes as the thinner oil will allow it to lock quicker, you can also play around with friction modifiers that also affect how the lsd behaves.

Cheers,

Guy