Roughly 350 miles after the diff was replaced, I had the diff fluid replaced to Mobil 1.

Also to answer the other question regarding the drained fluid by SpitfireS, I can't recall to an exact science, but if I recall it smelled like the old fluid a friend of mine and I drained out previously, the original fluid from the factory. It didn't seem exceedingly burnt or dirty. However, this is all recollection from a few weeks ago. Also, the work was done at a Honda dealer service Dept, a rather large one at that.

Thanks for the pointers so far guys.

 

Let's say you got a brand new diff from Honda, shipped from Japan. It is unlikely that it was sent with fluid. Usually, shipping companies will insist that auto parts that normally contain fluid, be drained before shipping. If it was new, it probably didn't get filled. If this was the case, then the dealer was left up to their own devices to find a fluid to put in it.
Let's say you didn't get a brand new diff from Honda. The same reasoning would apply as in my first scenario. The dealer would have had to put fluid in.
Go to the Oil Journals at the top of this forum and read the 2 threads near the top of that thread to see what happens when a dealer puts in the diff fluid they have in their parts dept.
Ask you dealer what kind of fluid they loaded your new diff with.

 

I actually just fired off an e-mail to my service advisor asking exactly that, as I just checked out the effects of the wrong fluid going into the differential. I guess I was not thinking that those early miles couldnt have an effect earlier, it just seemed really odd that the noise persisted, so i thought it was possibly a problem that wasnt addressed during the initial diagnosis and repair. Will be inquiring fully tomorrow. Thanks again.

 

Just as an update, I received my car back and they did confirm that the noise is coming from the differential. They did fill it with adequate fluid during the replacement. Just because it was asked earlier too, they did also check the wheel bearings.

The shop foreman does agree there is a slightly abnormal sound compared to others and does believe it is coming from the differential. However, since they just replaced the differential very recently, they are reluctant to swap it out again until or unless more symptoms arise or worsen where the issue will require more urgency.

I think I will seek another opinion at another Honda dealer, as I somewhat understand their reasoning, but that resolution doesnt sit well with me at all.

 

Could you get it confirmed the diff you have now was brand new?
Or was it an "exchange unit"?
Worth finding out.
Maybe there are markings on the diff that can tell?
(production dates?)

 

You know, I totally forgot to ask. I will try to confirm with actual markigns/data, as I was informed that it was 'new' previously.

 

I've cleaned my old diff core before shipping it back to Rick's and I have looked for markings, dates or codes.
I've seen some, but I do not recall what numbers or anything.
(and they dont show on the pictures)
And I certainly do not know what they mean.
My new (Comptech) core also had numbers on it.
Sorry to say I did not write them down for you to compare.

 

the symptoms, as other members pointed out, sounds just like my diff. my diff does make that sound but it's due to changed 4.57 gear. this was a earlier version and I believe it's been corrected with 4.57r or 4.56. if you happened to notice any metal shaving while you change diff fluid, you might be in trouble but if not, it might be possible that the gap on final gear - there's a term for it and I forgot what they call it - might be set too tight. but this gap should not be changed once FG is installed. I wish i was more helpful. good luck.

 

i have the same problem but its more like a rattling when at cruising speeds and only from 4k-5k. that is the only time it makes te noise

 

My local Honda dealer sold me the wrong DIFF fluid but I didn't find out till 5 months after the fact when I read the Oil Journals. I paid them a visit to address the issue and the parts guy agreed it was the wrong fluid. The service manager told me to replace it with the proper fluid and expected me to handle it on my own but I just stood there and said nothing. He then asked what I wanted from them and I requested they change the fluid. It was their mistake and they still tried to screw me. I have some light ,whining drivetrain noise but can't pinpoint where it's coming from but if my DIFF goes I'm gonna hold them responsible. Thanks to the Oil Journals.