My '05 S2000 has 6,800 miles on it. I changed the diff fluid this weekend to Mobile 1 75w90. I only found two tiny shavings on the drain plug magnet and I understand this is completely normal. For some time I have been hearing a whine coming from what I believe is the differential. The whine is only noticeable from 52 - 60 mph in 5th and 6th gear at a constant speed or while slightly accelerating. The whine stops immediately if I let off the accelerator or put it in neutral.

I was really hoping that the whine would go away but to my dismay, it may actually be slightly louder now that I've gone to synthetic gear oil.

Is this normal or should I have my dealer take a look?

 

I've been noticing quite a bit of gear whine this summer too. Even more so after switching from LE607(dino) to LE1605(semi-synthetic). It's been a hot one here in Texas, so I've been driving with the top up. The road temps are taking the gear oil to higher temps quickly, so it doesn't take long for the whining to start. I think I may try a 85W-140 dino GL5 next summer, if there is such a thing.

 

My previous 05 and my current 06 both demonstrated a faint whine during the same circumstances described. I briefly used Mobil 1 75w90 previously and I'd venture to say that's when the whine was the loudest and now the quietest after I've made the switch to LE1605 (last 10k miles). I have also experienced a lot quieter operation in all situations, which is not surprising given it's close to the spec'd 90 SAE.

 

https://www.s2ki.com/forums/index.php?showt...&#entry14052213

I'm running Amsoil 75-90 GL-5 Gear Lube...smooth as silk (for now)

but I also read this

http://www.bobistheoilguy.com/forums/ubbth...&Number=1215282

 

Identical to what I'm experiencing.

https://www.s2ki.com/forums/index.ph...pic=627087&hl=

Looks like it's common. I may swap fluid once I pick up a pump.

 

Sure its not the intake howl? That is the exact speeds it does it at.

 

Factory fill? Mileage?

 

^^^

If the noise isn't constant with speed I think it's the intake howl you are experiencing. Sounds to me the throttle is causing this sound with <=20% throttle input.

 

I have an apt with my dealer tomorrow and I'll let you guys know what the outcome is. The service manager is going to ride along so hopefully he'll agree that something is wrong.

If it was intake whine, it wouldn't be speed dependant. It would be RPM dependant. Being that it's only audible between 52-60 mph, and the whine is comming from the rear end, I would think it almost has to be a diff issue.

 

good luck with your appointment...