04 S2K: Whining from rear @ 3000-3500 RPM

[weneversleep]

I have an 04 S2000 with 23K miles on it. All Redline or Royal Purple fluids, maintained by Curt @ Track Time Performance.

I've started to notice a slight whine coming from the rear of the car in 6th gear, when between 55-60 mph, engine turning 3000-3500 rpm. Outside of that speed range, there is absolutely no noise. And, the whine is ONLY there when throttle is applied lightly, say when cruising down the highway. Lift throttle, whine goes away.

Any ideas? It seems to be getting slightly louder over time. Only thing back there to make noise under power would be the diff, right?

Thanks,
--michael

[Doctor Mugen]

do you have an aftermarket final drive gear like a Rick's 4.57?

[repiv]

All Redline or Royal Purple fluids

I've started to notice a slight whine coming from the rear of the car in 6th gear, when between 55-60 mph, engine turning 3000-3500 rpm. Outside of that speed range, there is absolutely no noise. And, the whine is ONLY there when throttle is applied lightly, say when cruising down the highway. Lift throttle, whine goes away.

Any ideas? It seems to be getting slightly louder over time. Only thing back there to make noise under power would be the diff, right?

Thanks,
--michael
First of all, which Redline and Royal Purple have you been using. If you were using Redline Shockproof, I have proven with oil analysis that this fluid is NOT good for our rear diffs. If not, then they had to have been GL-5 rated. Anything else and the rear diff will suffer.
A few things back there will make noise under power. The most likely is the rear diff. However, the wheel bearings can also make noise because when you apply power, you get a slight weight loading on the rear wheel bearings. If they are bad or going bad, they can make noise. The CV joints can also make a noise but that is generally a ticking sound, associated with vibration. Additionally, the rear propshaft CV joint can make a noise, too.
Have you tried running at that speed, but in 5th? That might eliminate the tranny output shaft bearing.
The Doc has a good question.

[weneversleep]

No, the car is completely, utterly, bone stock.

I don't know exactly what fluids are in the car--Curt put them in. I would think that with the amount of S2000s that Curt works on, he wouldn't put the wrong kind of fluid in.

Bearings going bad at 23K sounds strange to me, but I can have that checked.

Yes, I've tried running in 5th, and the whining is there, but a little fainter.

I appreciate the help. I'll just have to bring the car into Curt's to have it checked out.

--michael

[twizted]

that is the same problem i'm having.... and It also does it when I press the clutch in at that speed... I have a feeling its a bearing:(.. thats big bucks ain't it?

[repiv]

that is the same problem i'm having.... and It also does it when I press the clutch in at that speed... I have a feeling its a bearing:(.. thats big bucks ain't it?

That depends on what's going bad. If it's wheel bearings, then you're looking at pressing out the bearings and putting new ones. This will involve removing the rear wheel hubs and ending up with a wheel alignment.
If it's outer pinion bearing in the rear diff, this would be the least complicated job, but still a few hours works.
If it's the inner pinion bearing, this would involve taking the diff apart and lots of hours of work.
If it's the ring and pinion alignment, this would be the same - hours of work.

[twizted]

that makes me feel sick.. I just got her and was a little hard on her because you know.. had to let out some built up steam. I really regret that.. I learned all about the cpv in the burnout box.. never again. anyways.. I'm going to change the diff fluid tomorrow and I'm expecting to see some discolored fluid, Thanx alot "repiv" for all your advice and knowledge, I tried the whole gps at 60mph thing and the gears are stock, I've always used royal purple in my vehicles and I could tell the diference especially in my stock car, when I switched to purple, the overall engine temp dropped 30 degrees cooler then normal during the whole race compared to non synthetic.. but I wont put it in my hondas rear just because I trust your word.

[S2Kr]

Hi Dave,

I'm running Richmond's gears,4.57 R.and using Ammsoil 75-W140,GL-5.and still have a whining noise in the diff.

Would you be kind enough,to test drive my car,at Lake George,and tell me ,if the noise,is normal ???

Thank's,

-Emil.

[repiv]

Hi Dave,

I'm running Richmond's gears,4.57 R.and using Ammsoil 75-W140,GL-5.and still have a whining noise in the diff.

Would you be kind enough,to test drive my car,at Lake George,and tell me ,if the noise,is normal ???

Thank's,

-Emil.

Most certainly. I'm sure we can find the time to go for a run down the road and back. I would expect there to be some gear whine with Richmond gears. We can discuss a couple of other ideas I have when we do this.

[raymo19]

Not to suggest that the whine is not a concern with a stock diff or that a premature failure is not a possibility but it's also just as likely that the car will continue as is with the whine no better or worse for many thousands of miles. Some of them are just noisy even though they're within tolerance.

A straight 90 weight GL5 or even a multi-viscosity heavier gear lube like a 80W-140 will sometimes mitigate the noise.

[S2Kr]

Most certainly. I'm sure we can find the time to go for a run down the road and back. I would expect there to be some gear whine with Richmond gears. We can discuss a couple of other ideas I have when we do this.


Thank's Dave.:thumbup: