[spatz]

Hi all
We have had our 2015 CLA 200 Auto for around 6 months now , I have noticed an annoying whine from the transmission when on the overrun and coasting which is worse between 35-40 mph as the car is used around town a lot this whine is very noticeable and unlike mercedes , the car was put into the selling dealer for investigation but the response was "there is nothing wrong they are all like that" so if that is true how many more of us are tolerating noisy transmissions?

 

[jmc]

Might be a bad bearing??
Consider sticking a small microphone under the bonnet ... or at least try an in cabin recording??

 

[spatz]

I'm taking the car back to road test with the dealer technical specialist next week so I will record the noise as a back up but it does it all the time so we'll see what they say, I've worked for BMW , MB, and Volvocars in the past and driven lots of those models and never heard such a thing on a car with only 8000 miles up so for the dealer to say, no to its fine makes me think they are not interested in even looking at the problem, of course the second they agree it is noisey they then have to sort it.

 

[jmc]

I'm taking the car back to road test with the dealer technical specialist next week so I will record the noise as a back up but it does it all the time so we'll see what they say, I've worked for BMW , MB, and Volvocars in the past and driven lots of those models and never heard such a thing on a car with only 8000 miles up so for the dealer to say, no to its fine makes me think they are not interested in even looking at the problem, of course the second they agree it is noisey they then have to sort it.

A noisy bearing may bust before warranty expires ... though collatorals will be bad

 

[spatz]

UPDATE:-
This noise referred to by Mercedes as (Howling noise between 60 km/h and 80 km/h in acceleration and deceleration mode) is a known issue going well over a year
with some DCT7G transmissions , - it is simply cured by the installation of a resonance damper on the short drive shaft , have now tested the car and
the howling noise has gone.
A quick fix indeed ,very pleased the car did not req to have the transmission taken out , it is now enjoyable to drive

 

[weiyun]

Good to hear. So the question is, why does it happen to some and not others?

 

[jmc]

Glad to hear of the well documented fix ...
As to the "why" a resonance suggests some mechanical design parameter (eg rotational harmonic) violation due to material and density variances ... though "where" they installed that damper may be indicative ... towards the engine or towards the wheel or smack in the middle?

 

[spatz]

Ok, This is what I know from a MB tech info document,

The gearing of the spur gear excites the side shaft at its natural frequency > a howling noise can be heard
The damper is fitted close to the cv joint , effects a few variants diesel or petrol.

hope this info helps anyone else dispairing at the thought of living with a noisey transmission , it might just be a ten minute fix

 

[jmc]

Ok, This is what I know from a MB tech info document,

The gearing of the spur gear excites the side shaft at its natural frequency > a howling noise can be heard
The damper is fitted close to the cv joint , effects a few variants diesel or petrol.

hope this info helps anyone else dispairing at the thought of living with a noisey transmission , it might just be a ten minute fix

Thats good info to know.
Some time when you feel inquisitive perhaps you can upload a picture of this said fix?
We are a curious sort ... ?
And do you have the number for the service bulletin for this fix? It might be printed out on your repair order.

 

[tekfoc]

Honda's use them for many years

 

[jmc]

Honda's use them for many years

None of my 3 Acura (well Honda Japan) drive lines had any external harmonic balancers ... instead the x-sections had minor mods (done and painted over at the factory) so those were dynamically balanced parts. Not sure if the American Honda lines did that though ...

 

[tekfoc]

It's a round rubber bushing going around the inner part of the axle.
My old Honda had one.

 

[jmc]

It's a round rubber bushing going around the inner part of the axle.
My old Honda had one.

Yup ... I have seen those external harmonics modifiers ... and luckily in my cases they balanced
the metal shafts themselves instead ... those were the good o' days ...

 

[Stage2CLA45]

UPDATE:-
This noise referred to by Mercedes as (Howling noise between 60 km/h and 80 km/h in acceleration and deceleration mode) is a known issue going well over a year
with some DCT7G transmissions , - it is simply cured by the installation of a resonance damper on the short drive shaft , have now tested the car and
the howling noise has gone.
A quick fix indeed ,very pleased the car did not req to have the transmission taken out , it is now enjoyable to drive

Hey Hi, I know its a long shot but do u have the part number of this resonance damper that was fitted on the short drive shaft close to the CV joint?

Any members know what is this damper in discussion and where is it located?

I am still trying to figure out if it is replacing an existing damper or adding an additional damper.

Thanks all!

 

[Stage2CLA45]

Update: I changed the drive shalf damper part number A2464110015 (not sure if its the one that was mentioned) but it didn't solve the problem

Its a pity Spatz didn't come back to add more details on what was done.

Anyone still holding on the their CLA45 and still has this issue? Maybe we can share and help solve this issue. Cheers!

 

[Gla45amgg]

Hi, did you guys figure it out? My car is making whining noises from the rear at higher speeds. Even when the engine revs back down (from eco mode) and I'm going 140km, the noise is still there. the faster I go, the higher pitch it becomes. If the car slows down, the noise also starts pitching down until you cant hear it anymore.

 

[nogosen9]

?


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[wokeva86]

?


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What?


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[jmc]

speed correlated pitch
bearing whine?

 

[Stage2CLA45]

Hi, did you guys figure it out? My car is making whining noises from the rear at higher speeds. Even when the engine revs back down (from eco mode) and I'm going 140km, the noise is still there. the faster I go, the higher pitch it becomes. If the car slows down, the noise also starts pitching down until you cant hear it anymore.

hey hi! seems like it is the dreaded issue I mentioned. though mine seems to occur at two speed ranges now, 50-70 and 90-110 both during acceleration and deceleration. so far it comes to suggest that the rear diff pinion bearings are the culprit.

its seems like quite isolated because not many people have shared this issue.

I will be trying out a thicker rear diff oil with Nulon additives to see if it will help soon. I will update the outcome. Fingers crossed.