Rear end noise

[poolshark743]

Have any of you ever had an issue with Mobil 1 75w90 gear oil? Ever heard that it may cause our diffs to be noisy? I am getting a whirring noise from the rear end. I recently changed the pads and thought I forgot to lube something up so I took everything apart and relubed it all. Still the noise. I recently changed the diff fluid 2k miles ago so the other day I drained it again just to look at it and refill it with new fluid. Fluid looked good and the drain plug showed no signs of anytiing floating around in it. I get no clicking when I start uplike the wheel bearings are going bad. I hear this noise, which sounds like a stuck pad against a rotor, when I am in gear and when I am out and even when I brake. I took it by this place by my work, Firestone which I would never take my car to but hey advice was free, and one of them told me to switch back to honda fluid. He stated he used to own one and the same thing happened. He changed fluids and all was ok. What do you think any help will be appreciated.

[darkside]

Mmm dont know about mobil one, I use some JDM mitsu straight 40 for the evo and have no probs or noise.

[SondraS2k]

I've had the Mobil 1 stuff in both of my Ss and Stefan has had it in his for 85k+ miles with no issues, so I don't think it's that. I wish I had more answers for you!

[Jasonoff]

What have you done in terms of "how you drive your car" in those 2K miles?

Any clutch drops hard shifts?

[repiv]

Many, many S2000 owners including myself, have used Mobil 1 75W90. I've been using it in mine after the 1st year. I've even got 4.44 gears. With stock gears, there should be no gear noise unless they've been damaged in some way or if the wrong fluid was put in there at one time (like Honda's VTM-4 fluid, which a few dealers have mistakenly thought was the "OEM" S2000 fluid - a couple of weeks of this fluid in the diff and it's permanently damaged).

BTW, there is NO Honda (car division) rear diff fluid for this car. You have to get it from their motorcycle division. If he's telling you he put in OEM diff fluid, he's blowing it out his butt.
If you suspect something amiss with the fluid, get a bottle of any SAE 90, GL-5, hypoid gear oil from a motorcycle shop, Honda if this makes you feel better about it and give it a try. Also, many of us have routinely put in an extra 100cc overfill for added heat dissipation and lubricating medium. Do this by jacking up the car from the driver's side after you've put in the correct amount.

PS. Do you have aftermarket gears?

[poolshark743]

No stock gears. I never shift hard and have never dumped the clutch. Of course there are sometimes I spiritly drive to get around someone but I always rev match. Any advice on what I should do if the fluid change doesn't work?

[repiv]

What have you done in terms of "how you drive your car" in those 2K miles?

Any clutch drops hard shifts?
Good point. Hard driving can place a lot of wear and tear on the inner and outer pinion bearing of the diff. When one of these get pitted or scored, you will hear some noise.

Another question ................... Did you put any sort of additive into the diff? None is required and none should be used.
Additionally, other things that could make noise like this are the wheel bearings. You don't have to get the single click to show that they are abnormal. The hub nut can be torqued correctly and still the bearing could be getting worn. You could have a propshaft bearing on the way out.
Oh, check the ABS sensor ring. It may be just making contact.

[poolshark743]

Never put any fluid additive. How do I check all the bearings and propshaft stuff. I can do the work myself but not sure where it all is at on this vehicle. I would rather do the work myself, besides noone wants to touch it and I hate taking it to the stealership.

[Jack Broughton]

I have been using Mobil 1 products for many years so it was quite natural to fill up with 70W90 in my S about a year ago. Shortly after the change I notice a clicking noise when making a turn from a stop. I let this go on for a while until I could figure out where and why. As it turned out the noise was from the differential and was caused, the best I could determine, by excessive friction between the LSD gears. I changed lubicant to Royal Purple Synthetic of the same viscosity and the noise ceased. There was no evidence of a mechanical problem in the Mobil ! when it was removed, but I expect that it would take quite some time for physical damage to occur.

[repiv]

How do I check all the bearings and propshaft stuff. I can do the work myself but not sure where it all is at on this vehicle.
These can be tough if you've never had bad bearings. For the wheel bearings, you would normally jack up the car securely and grab the tire and see how much "wiggle" room there is (top, bottom, front, rear, in and out). If the bearing has gone south, there should be an abnormal amount of movement. (More than a millimeter or so.)
The propshaft CVs are just behind the tranny and just in front of the rear diff. You'd have to get under there and also check for abnormal movement and free play in all directions (except fore and aft, as this is normal).
Oh, another thing I forgot is the rear output tranny shaft bearing. These have been known to fail and make a whining sound that seems to come from the rear. Check this for free play by trying to move the output flange on the tranny.
The ABS ring, you can watch very carefully as you turn each wheel. There should always be a small gap (air space) between the sensor and the toothed ring.
The inner and outer rear diff pinion bearings are real tough. You'd have to disassemble the diff and visually inspect those. I'd leave this as a last resort.

PS. Start by trying a different fluid. That's would be the cheapest and simplest.

[SondraS2k]

Never put any fluid additive. How do I check all the bearings and propshaft stuff. I can do the work myself but not sure where it all is at on this vehicle. I would rather do the work myself, besides noone wants to touch it and I hate taking it to the stealership.

Dealership=bad! If you need to take it somewhere, JC Autospec is pretty familiar with the S2000 and has done a great job for those of us who have taken our cars there (I won't let any other shop touch my car). I can't recommend them highly enough.

[poolshark743]

If I can just take it somewhere and get a diagnosis is all I need but most places want to do the work. Will JC give me a diagnosis?

[SondraS2k]

If I can just take it somewhere and get a diagnosis is all I need but most places want to do the work. Will JC give me a diagnosis?

I can't imagine why not.

[poolshark743]

I called them and they said half hour fee to diagnosis. Thanks. I will go and see them on Wednesday.

[kmcs2000]

any good shop in the sacramento area where i can take it in to get check? i hear a whining noise in my diff too...

[dumbkid]

Check Your Drive Shaft Bolts.

[thereur]

LE 607/LE 1605 quieted down my diff nicely.

[S2KPUDDYDAD]

Lots of good advice here:thumbup:

Did you have the noise before the brake job? if not then look back at the brakes is what I'm thinking.

Good luck

[twizted]

I'm having an issue also, I purchased my 05 about 3 weeks ago and I love it... but recently i've noticed that my rearend whines when I cruise between 85 and 95 kph about 55 mph. but only when there is little load on the rear like maintaining speed or coasting. I don't know if it was there when I bought it. it has just over 30k miles on it. would replacing the diff fluid help? or is this normal?

[repiv]

I'm having an issue also, I purchased my 05 about 3 weeks ago and I love it... but recently i've noticed that my rearend whines when I cruise between 85 and 95 kph about 55 mph. but only when there is little load on the rear like maintaining speed or coasting. I don't know if it was there when I bought it. it has just over 30k miles on it. would replacing the diff fluid help? or is this normal?
Well, this somewhat depends on if you have a stock rear diff or if you have aftermarket gears in there. A stock rear diff should make no whine at all. It has been reported that the 4.56/4.57 Richmond gears do make noise. The later generation make a bit less whine. Using a thicker gear oil like the new LE product or a 75W140 has been shown to reduce the whine considerably.
If this car is new to you, it would be wise to find out what's in the rear end and to do a fluid change according to what you find out. If you are running stock gears go with the LE or an SAE 90 hypoid gear oil (GL-5) or a 75W90 GL-5 gear oil like Mobil 1.
If it's a Richmond gear, go with the LE or the 75W140. Not only is this a smart thing to do since you don't know when the last change was, this will show you fairly quickly if it's actually the rear diff that's whining. If the noise doesn't do away after the fluid change, then you need to be looking at other stuff, like wheel bearings, brakes, etc.

[twizted]

Thank you for the reply, that was very informative.
How can I tell if the gears are stock or aftermarket? And I'm going to go with royal purple fluids in the car, is it wise to change the trans fluids also? or should I wait until the scheduled service?

[repiv]

Thank you for the reply, that was very informative.
How can I tell if the gears are stock or aftermarket? And I'm going to go with royal purple fluids in the car, is it wise to change the trans fluids also? or should I wait until the scheduled service?
I would strongly advise against Royal Purple. It's only claim to fame is that it's PURPLE. People have had problems with RP in the S2000. They don't make suitable fluids for every S2000 application. You might do OK for engine oil, but you may be very sorry if you use their product for tranny and rear diff.
A typical suggestion would be Mobil 1 or Castrol syntec 10W30 for engine, Honda MTF for tranny and the fluids I've already talked about for the rear diff.

To tell if you have aftermarket rear gears, go on the highway where you can set the cruise control. You must then have an alternate means of clocking your true speed. A GPS would be best. Unless you know exactly what gears you have in your rear diff and that you know for a fact that there is a speed compensator installed, you can't rely on what your speedometer says. Get into 5th gear around 60 mph, then use your "accel and decel" buttons on the CC to get to exactly 60 mph by GPS.
A stock geared AP2 with a GPS confirmed speed of 60 mph in 5th gear WILL be turning at 4000 rpm. If it is not, then you have an aftermarket gear set. *This is also assuming you have stock sized rear tires.

PS. If you don't have a GPS, then you can get paced by another car with a known accurate speedometer. You just need to know when you are doing exactly 60 mph true speed.

[BearNVa]

Well I have the same problem... I thought it was the clutch because my clutch felt like it was getting too soft so I had it replaced today. Then after driving for a while the noise started again. I had all my fluids changed when I had the new clutch installed. So I guess my next guess would be the driver side rear wheel bearings because that's where the noise is coming from. I'm gonna jack the rear up tomorrow and do the little test as stated above. I'm lowered on coilovers about 1.5" and I'm running wider tires 255 on the rear. I would take it to a dealer but there is no dealer that I really trust plus they rape you on labor costs... Hopefully I can figure out what it is because it is really annoying!

[repiv]

Well I have the same problem... I thought it was the clutch because my clutch felt like it was getting too soft so I had it replaced today. Then after driving for a while the noise started again. I had all my fluids changed when I had the new clutch installed. So I guess my next guess would be the driver side rear wheel bearings because that's where the noise is coming from. I'm gonna jack the rear up tomorrow and do the little test as stated above. I'm lowered on coilovers about 1.5" and I'm running wider tires 255 on the rear. I would take it to a dealer but there is no dealer that I really trust plus they rape you on labor costs... Hopefully I can figure out what it is because it is really annoying!

Man, I hope you didn't do a clutch job solely on the basis that your clutch pedal felt "soft". There are several things you could have done first that are much cheaper and faster to figure why a clutch is soft. A worn out clutch won't make pedal feel any different. Slippage tests should have been done.
Running wider tires isn't a big issue either so long as the diameter is similar to stock. However, being lowered may have contributed to your inner CV joints taking a crap. This is well known whenever an S is lowered if the CV joints have already developed distinct wear patterns already before lowering. Although it generally begins with vibration on acceleration, it is quite possible that noises will accompany this. Did you ever install spacers when you lowered the car?
A wheel bearing that is going and then making noise can be caused by inadequate torque on the rear hub nuts. Even fully torqued nuts can loosen due to thread stretch on the axle end and nut. A bad bearing will usually get abnormally hot after a good drive. Feel around (carefully) the hub area and compare the temp with the other side. If there is a difference in temps, it's likely bearing.
So far, people have posted that they have the "same" noise, yet nobody has given a precise and accurate description of exactly what the driving parameters are when they hear this noise. Such a description is paramount if there is any chance of someone coming up with an applicable idea. You can chase a lot of wild geese before you finally catch that little rubber ducky.

[BearNVa]

Well I did replace the clutch because because someone recommended it and I'm actually glad I did the car feels I lot better now however it still didn't fix the problem. I'm not rich but do not regret replacing it. Well here is the best I can do as far as describing the driving parameters. When I first start driving the car when it's cold the car wheel doesn't make the noise however after about 20-30 mins of steady driving it starts like metal rubbing metal and you only hear it when driving slow or coming to a stop. It sounds like a steady and constant rhythmic noise, so I'm figuring heat has a lot to do with it. The longer I drive the louder it gets. I'm planning on replacing the rear bearings along with the diff because I found out that the metal shavings in the fluid were actually teeth and not just shavings so before it drops I'm going to replace it.

[repiv]

Well I did replace the clutch because because someone recommended it and I'm actually glad I did the car feels I lot better now however it still didn't fix the problem. I'm not rich but do not regret replacing it. Well here is the best I can do as far as describing the driving parameters. When I first start driving the car when it's cold the car wheel doesn't make the noise however after about 20-30 mins of steady driving it starts like metal rubbing metal and you only hear it when driving slow or coming to a stop. It sounds like a steady and constant rhythmic noise, so I'm figuring heat has a lot to do with it. The longer I drive the louder it gets. I'm planning on replacing the rear bearings along with the diff because I found out that the metal shavings in the fluid were actually teeth and not just shavings so before it drops I'm going to replace it.
You are likely very correct about this being a heat related issue. Wheel bearing or rear diff are strong possibilities. Note my comments about checking the wheel bearing from my previous post. Have you ever had the clicking sound when initially driving forward or reverse from a stop? This would indicate that the hub nut was inadequately torqued. Not resolving this immediately would cause bearing damage. If you are going to do bearings, before you take them off, check what kind of torque is on those nuts. If you can increase the torque to 221, then they have come loose and you may have your answer.
As for the rear diff, I must leave the analysis of the used fluid and what's on the drain magnet up to you since I can't be there to see it. In this case, I suggest changing the diff fluid to a thicker fluid, if only to test the noise afterwards. Try some GL-5 75W140 and go out and drive till it gets hot. Take note if the noise alters in any way. If it does, then rear diff is the most likely source of the noise.
One must also consider that your brakes pads are getting thin for numerous reasons. Pop off the wheels and check them for thickness, both inner and outer pads. They should be more or less even with each other and also even with the pads on the opposite side of the car.