To the OP:
Bad luck

Based on your pictures it looks to me the oil was not that old.
My guess is it was changed, probably with a multi weight like 75W-90.
Multi weights diff oils still are very popular... for some reason.
That goes against Honda's recommendation (yeah.. that's a FACT! )
Yes.. I know about the Canadian 80W-90 diff oil service letter.
Up to today the MY07 manual the SAE 90 GL-5/6 recommendation hasn't been changed though.
I'm not saying in this case a straight SAE 90 would have saved the day = diff.
It also doesn't help.

To Ckit:
Based on your posted picture (and nothing else!) I think the wear pattern on your 4.57 pinion is kinda odd.
NOTE: it might be the lighting!
I've put a circle in your picture.
In there you can see an "unused" part of the pinion.

That makes me believe the checking distance wasn't correct.
It seems like it was only wearing on the top of the pinion teeth.

What shim was used?
What checking distance was engraved on the set?
(I've asked this in the other thread too.. no answer yet)

 

spitfires,

very good questions!

 

This is disturbing me. Ive had some diff whine(more than a typical s2k) for sometime now. I just replaced my inboard joints with the newer versions to remedy a vibration on acceleration. Thats all well now, however.....im worried about this bloody diff!!!

 

Please don't be bothered by these pics, as I beleive these are both extreme cirmunstances. I put my diff through repeated hell. And once it stated wining, I knew I broke something permenant on the downshift. When it did finally go the wining noise had become louder, now at all RPM's that very day, with the noise no longer dependant on load. Then boom.

Lesson Learned : Unless you have the $$$, or want the experience of changing out diff's, Learn to lay wheel properly, or not at all. The car is great, It's just the downtime thats not worth the risk it to me at the moment.

 

Changing the diff is the easy part. My biggest concern is the replacement diff doing the same thing! I can say that ive never done a full out launch and that im not that hard on it. Down shifting is more than likely the problem here. Several times ive done a rapid downshift and ive actually heard some tire chirping! Could this really be the cause??? I would hope not! We shall see if my diff is doomed in due time.