FWIW the 75/110 is a better choice it is much closer to the SAE90 wt spec if I remember correctly.

 

yes, this is only posted in the FAq, and two hundred other posts, and even the post five above this. Let's stop pandering to those who can't use the search function.

 

Really? I'm not the OP but I was recently looking for the same answer and this definitely isn't obviously. I do agree with use of the search function but s2ki has the worst search function of any forum I've used. It took me some time but I eventually found it. Maybe I just suck at the internet but I couldn't find a definitive answer in this FAQ or a few searches.

FAQ

Differential fluid search

 

I've been using LE stuff for at least 5 years now. Used to use 607, now using 1605. Some really great stuff.

 

I completely agree we should search first. But it's sometimes difficult to find a perfect answer in the archives. I picked through a lot of old threads when I was trying to choose a diff fluid and I don't remember reading that 75w-110 is the closest to SAE90.

The reason I ended up with 75w-90 is because there were knowledgeable people recommending both and I couldn't find anyone reporting problems with 75w-90, so I decided that 75w-110 seemed like overkill. Plus from the threads I read, more people in my regional forum used 75w-90.

I'm not saying this to make a case for 75w-90; just to point out that just because someone came up with a different answer doesn't mean they didn't search. And to say that I appreciate the info being posted here about how 75w-110 is a better match to the SAE90 spec. (Thanks, Swiftoy ) In light of this, I may switch to 75w-110 next time.

 

It has been apparent ever since SAE J306 went into affect, there has been much confusion as to what gear oil viscosity to use. Please don't belittle those who are not aware of the changes on s2ki. Some have never heard of the changes, and the search function is pretty worthless. Here is a good summary of what took place with J306 changes:

http://www.lubrizol.com/DrivelineAdditives...ifications.html

 

Nice link Indymac, great info.

Dont' sweat the 75w90 thing, Puddydad still recommends 75w90 for daily drivers, it isn't going to casue you any harm in daily driving unmodified S2Ks. I trust his opinion as he's torn apart enough diffs and has real work experience on this subject. You are safe because the minimum thickness is still acceptable.

I do think 110 is a better choice as it lands right in the middle of the minimum and maximum viscosity range of the old SAE90 spec.

 

Redline 75-90 GL5 has always treated me well.

Remove the fill plug before the drain plug.

Remove the fill plug before the drain plug.

Remove the fill plug before the drain plug.

Remove the fill plug before the drain plug.

Remove the fill plug before the drain plug.

Remove the fill plug before the drain plug.

Remove the fill plug before the drain plug.

Remove the fill plug before the drain plug.

 

I have put mobil1 75w90 to the ultimate test and it comes out spotless. Even after 35k of very hard driving, drifting.....

 

what the? US dealers don't carry the OEM SAE90 API Honda hypoid gear oil?
Strange, I picked up a bottle from my dealer last week