bit of a thump when selecting drive from cold

[such01]

I have noticed recently when starting in the morning and selecting D there is a bit of a thump when engaging gear. It does not do this when warm.

Not noticed this before. The ATF fluid was changed around 7k ago.

Should I be concerned?

Thanks

 

[whitenemesis]

Check atf level again when fully warm

 

[such01]

thanks, never done that before, how?

 

[gianton]

If ATF fluid was changed recently, then a worn trasmission mount is my 2nd thought.

 

[whitenemesis]

Worn mount worth checking but if thump goes once warmed up...

 

[whitenemesis]

thanks, never done that before, how?

You'll need a transmission dipstick and the ATF must be at operating temp ~80c and selector in Drive.

Find yourself a good Merc independent, most would check for a nominal fee. Whereabouts are you?

 

[such01]

thanks, I'm in kent nr dartford. Is there no way of checking DIY?

Also re worn transmission bush, how does one check that and is it an easy repair?

Cheers

 

[4life211]

Conduction plate contamination.when it is cold the conduction between electric valve and the plate is poor .when you replaced atf have you washed your conductive plate with electric spray ?

 

[DSM10000]

thanks, I'm in kent nr dartford. Is there no way of checking DIY?

Also re worn transmission bush, how does one check that and is it an easy repair?

Cheers

You will need a suitable dipstick and n external thermometer to measure the ATF temperature.

Probably cheaper to get a specialist to do it for you.

 

[such01]

Conduction plate contamination.when it is cold the conduction between electric valve and the plate is poor .when you replaced atf have you washed your conductive plate with electric spray ?

MB dartford replaced the ATF. Is the washing of the CP part of the procedure?

Thanks

 

[such01]

You will need a suitable dipstick and n external thermometer to measure the ATF temperature.

Probably cheaper to get a specialist to do it for you.

where does the dipstick go and can Icarsoft MB11 read the ATF temp?

 

[David404]

I have a 2008/09 W211 with the OM642 engine and 7G-Tronic tranny which I guess is very much like yours. Mine doesn't have a transmission dip stick.

My understanding is that the oil level is set with the tranny at 80c and its tower/overflow device in the transmission sump pan, the tranny is filled until oil overflows over the tip of an internal tower in the gearbox.

Think is temp is normally checked with an IR/Laser thermometer directly off the sump pan.

I'd go back to MB Dartford and ask them to re-check.

 

[4life211]

MB dartford replaced the ATF. Is the washing of the CP part of the procedure?

Thanks

When replaced my car's ATF (7 litres of oil) the mechanic removed the valve's mounting plate ,remove all the electro valves and he wash the plate with electric spray.

 

[DSM10000]

where does the dipstick go and can Icarsoft MB11 read the ATF temp?

The dipstick goes into the fill tube for the ATF , it is will be at the rear of the engine , where the gearbox is, it has a protective plastic cover that is secured with a pin, I think the pin / cover may need replacing once the cover is removed.

As for icarsoft, no idea, have you tried their website or emailing them?

Overfilling a transmission can cause damage as well as underfilling, if in doubt get a professional to check and adjust levels.

 

[ernie]

The dipstick goes into the fill tube for the ATF , it is will be at the rear of the engine , where the gearbox is, it has a protective plastic cover that is secured with a pin, I think the pin / cover may need replacing once the cover is removed.

Not on the 7 Speed Tranny!

Ernie

 

[DSM10000]

Not on the 7 Speed Tranny!

Ernie

Where then?

 

[whitenemesis]

From the 7g (722.9) MB training pdf, page 10

Transmission Fluid Level
• No dipstick or dipstick tube
• Fluid level checked using overflow method
• Oil pan has overflow pipe clipped onto pan, above drain plug
• Fluid level must be checked at specified transmission fluid temperature
• Special filling station used to add fluid through drain plug

 

[such01]

thanks for all the feedback / suggestions.
I've had a look here:

W212 E Class Transmission Thump | Mercedes-Benz Owners' Forums

am I allowed to post that?

Anyway, when the weight of the car is on the parking brake, it seems to go into drive without the thump.
When using the parking brake on my drive and then selecting P there is some slight movement when taking my foot of the brake.
I have tried what's suggested above ie - stopped, footbrake, selected N, parking brake and then P, release foot brake which results in no roll forward when taking off foot brake.

Since doing this, D is engaged without any thump or noise. Perhaps that was the problem as the space on my drive has been reduced, hence being parked on a slight slope.

Maybe the issue is due to the weight of the car being held by the transmission ?

Thanks

 

[Petrol Pete]

where does the dipstick go and can Icarsoft MB11 read the ATF temp?

MB11 can display ATF temp, but IR pointed at sump does the same thing, these things are cheap now from any good DIY store if you don't have MB11.

Advantage of MB11 is you do not have to get under the car.

 

[such01]

thanks I have MBII not tried it yet, but problem seems to have been resolved so far once parking brake is engaged fully whilst in N.