Gearbox thump when cold

[Surreygraham]

Hi,
I have just bought a w212 E350 coupe with 55k on the clock. It’s a lovely car but......

When cold it will thump very loudly when changing down from 4th to 3rd (I think) at slow speeds. When the car is warm this completely disappears as a result it’s going to be a hard one for the dealer to find I suspect.

The forums suggest it’s some kind of component and not the gearbox itself.
Any thoughts would be appreciated.

Thanks

 

[DSM10000]

Firstly when was the fluid last changed, where did you buy it from and what does the service history show?

Secondly: The 7G and 7G+ boxes do have a reputation for slightly harsh downshifts when cold.

It may be a problem with the valve body but the mileage is low for those faults to manifest. If bought from a dealer then it is down to them to fault find and repair.

 

[Jigglyjohnson]

Petrol or diesel ? The gearshifts can be thrown out if there are any defects with the engine. If you had a serious issue with the box I'd suspect it would be there all the time the diesels used to suffer with the air filter blocking up and can cause issue with the air flow meter readings. Even if they have been changed on the service schedule I'd still check them if they look blocked for piece of mind just change them and reset all engine values. I'd also check the gearbox oil and filter to see if it has ever been changed again if you can tell piece of mind get it changed and test again

 

[markjay]

Does your car have the older 7g gearbox, or the newer 7g+?

My experience is that the 7g+ gearbox can be harsh when cold.

That said, what you can do is the following:

- Get the car of STAR to check for any TCU fault codes.

- Get the transmission software updated to the latest revision.

- Change the ATF and filter (if not changed already at the due internal - 5 years or 77,500 miles for the 7g+).

If after that the problem still persists, it will need to be investigated further.

 

[Surreygraham]

Thanks everyone.
I don’t think it’s the gearbox as it would be there all of the time.
I bought the car privately with a full service history and the balance of a warranty.
I’ll get the codes checked and the oil changed and see what that looks like.
This is my first Mercedes and it seems a great car apart from this minor issue and the less than healthy mpg- but I guess that’s the price of the 350 engine!

 

[Yex]

Depending on whereabouts in Surrey you are based it might be worth a call and a drive down to see Ollie and the team at Prestige Car Service:

Mercedes Benz & Smart Specialists | Prestige Car Service | Horndean, Hampshire

www.prestigecarservice.co.uk

Great team who are worth contacting if you have an issue you are concerned about.

 

[mersum1es]

I could well be gearbox, many problems there are temp related.