Jump to content

Recommended Posts

Hello, good day to you.

I would like to have some advice on the gearbox jerking issue of Mercedes-Benz, A class model.  Is there any discussion on this topic?  Hope you can direct me to that link, thank you.

↡ Advertisement
  • Praise 2

Share this post


Link to post
Share on other sites

Hello, good day to you.

I would like to have some advice on the gearbox jerking issue of Mercedes-Benz, A class model.  Is there any discussion on this topic?  Hope you can direct me to that link, thank you.

 

Created a new topic for you. Please post your issues here.

Share this post


Link to post
Share on other sites

Hello to all MB A-class owner (transmission: 7G-DCT),

 

Does anyone encounter the transmission jerking during gear changing or jerking even stay on 5th gear?

Sometimes after jerking, the gear (at 7th) will not change to lower gear when slowing down to 50km/hr.  The paddle shifters is not response as well.  When the vehicle reached less than 20km/hr, the gear will change very fast from 7th to 2th.

 

The temporary solution is to switch off the engine and re-start.  Everything will back to normal.

Unfortunately, this jerking issue is intermittent.  I sent my vehicle to CC but they can't find any problem.  Sign...

 

Appreciate for any feedback, thanks.

 

 

 


1st gen A class or the latest. Need to be more specific on the year made.

Sorry, not sure which generation.  It was manufactured in year 2016.

  • Praise 1

Share this post


Link to post
Share on other sites

It is time to get 2nd opinion from Merc specialist.

 

Anyone can intro?

↡ Advertisement

Share this post


Link to post
Share on other sites

Under warranty right? Have to let CnC manage it. 

 

No point going outside for a 2nd opinion.

 

Video it and show them if you can.

Share this post


Link to post
Share on other sites

Under warranty right? Have to let CnC manage it. 

 

No point going outside for a 2nd opinion.

 

Video it and show them if you can.

 

A lot of times, staff has no idea no matter how many times you go.

 

It is better to pay someone to diagnose.

 

After that, tell CnC how to fix it under warranty.

Share this post


Link to post
Share on other sites

If no warning lights lit up the AD will not be able to find anything. Cos what they do is plug in the diagnostic tool to check for faults. If nothing show up to them there's nothing wrong. even if you go other places to get a 2nd opinion they will also do the same. What you will get is the same answer.

 

If I'm not wrong it's a sign the DCT clutches are worn. It's time for replacement. Once the clutches are worn they will slip much like a manual transmission clutch but becos DCT has two clutches when one clutch couldn't engage due to slipping the ecu or computer will try to engage the next one. As you have read or watch video on DCT one clutch engage odd number gears, other one engage the set of even number gears so you see your gears hopping like what you mentioned.

Share this post


Link to post
Share on other sites

its a 2016 unit and surely the wear and tear is not that bad, unless used it like  a PHV.

 

Sacly WOT all the times and launch control for all traffic lights... :blink:

Share this post


Link to post
Share on other sites

It is a DCT, if you drive like an automatic car, the clutch will wear prematurely.

 

Do you let your car creep in? (Not depressing the accelerator pedal while letting the car move forward?)

That is a no-no for DCT.

  • Praise 1

Share this post


Link to post
Share on other sites

For a manual transmission clutch plate it will also wear. The half clutch during slow traffic or on a slope/ramp. It's the same type of wear you cannot get away from when it comes to driving.

 

Whether it's a manual transmission clutch or a DCT clutch the contact medium is the clutch plate. No way of avoiding the replacement cost. Torque converter the contact medium is the fluid or hydraulic oil inside the drum hence no clutch or clutch wear. There are always pros and cons to everything related to cars.

Edited by Watwheels
  • Praise 1

Share this post


Link to post
Share on other sites

If no warning lights lit up the AD will not be able to find anything. Cos what they do is plug in the diagnostic tool to check for faults. If nothing show up to them there's nothing wrong. even if you go other places to get a 2nd opinion they will also do the same. What you will get is the same answer.

 

If I'm not wrong it's a sign the DCT clutches are worn. It's time for replacement. Once the clutches are worn they will slip much like a manual transmission clutch but becos DCT has two clutches when one clutch couldn't engage due to slipping the ecu or computer will try to engage the next one. As you have read or watch video on DCT one clutch engage odd number gears, other one engage the set of even number gears so you see your gears hopping like what you mentioned.

Yes most likely is due to clutch issues. Just watched a angmo video last night on how to choose a used B-class, and the narrator mentioned about it.

Share this post


Link to post
Share on other sites

Yes most likely is due to clutch issues. Just watched a angmo video last night on how to choose a used B-class, and the narrator mentioned about it.

 

This DCT is still new to a lot of ppl including mechanics who are supposedly proficient but they still lack the relevance experience about the gearbox. Anyway....I hope TS can better communicate with the workshop mechanic to tell them his car's issue. Cos I know many ppl will just kpkb kick up a big fuss at the workshop and push everything to others. Knowing what is the problem is half the problem fixed.

 

It's just like going to the doctor. The doctor is not a fairy from the heavens he's just interpreting whatever the symptoms you tell the doctor. You know your body best. I so lor soh is becos I see many ppl communication fail and start to verbally abuse others. When you see something like this you know that person is an empty shell.

  • Praise 3

Share this post


Link to post
Share on other sites

This DCT is still new to a lot of ppl including mechanics who are supposedly proficient but they still lack the relevance experience about the gearbox. Anyway....I hope TS can better communicate with the workshop mechanic to tell them his car's issue. Cos I know many ppl will just kpkb kick up a big fuss at the workshop and push everything to others. Knowing what is the problem is half the problem fixed.

 

It's just like going to the doctor. The doctor is not a fairy from the heavens he's just interpreting whatever the symptoms you tell the doctor. You know your body best. I so lor soh is becos I see many ppl communication fail and start to verbally abuse others. When you see something like this you know that person is an empty shell.

 

I saw the same situation at the workshop where a customer was arguing with the mechanic, something along the line, "As a professional, how come you don't know how to advice on the issue when I explained to you." The mechanic just gave him the I have no idea what you're talking about.

 

I used to work as a IT helpdesk and people like to start with, " i have a problem with my computer ......". Full stop. No explanation of symptoms, how it occur, what is the situation you usually encounter the issue.

  • Praise 1

Share this post


Link to post
Share on other sites

Hello to all MB A-class owner (transmission: 7G-DCT),

 

Does anyone encounter the transmission jerking during gear changing or jerking even stay on 5th gear?

Sometimes after jerking, the gear (at 7th) will not change to lower gear when slowing down to 50km/hr.  The paddle shifters is not response as well.  When the vehicle reached less than 20km/hr, the gear will change very fast from 7th to 2th.

 

The temporary solution is to switch off the engine and re-start.  Everything will back to normal.

Unfortunately, this jerking issue is intermittent.  I sent my vehicle to CC but they can't find any problem.  Sign...

 

Appreciate for any feedback, thanks.

 

 

 

Sorry, not sure which generation.  It was manufactured in year 2016.

 

From D to R during parking, do you feel a jerk too? It comes randomly.

 

From 2 to 1 when slowing down to a traffic light, do you feel a jerk too?

 

From 2 to 1 when slowing down to a traffic light, before the jerk comes, do you hear a rattling sound too?

 

If the above are all true, then I know what's happening!

Edited by Pmet
  • Praise 1

Share this post


Link to post
Share on other sites

Most people don't know how to verbalize.

 

I saw the same situation at the workshop where a customer was arguing with the mechanic, something along the line, "As a professional, how come you don't know how to advice on the issue when I explained to you." The mechanic just gave him the I have no idea what you're talking about.

 

I used to work as a IT helpdesk and people like to start with, " i have a problem with my computer ......". Full stop. No explanation of symptoms, how it occur, what is the situation you usually encounter the issue.

 

Share this post


Link to post
Share on other sites

It is a DCT, if you drive like an automatic car, the clutch will wear prematurely.

 

Do you let your car creep in? (Not depressing the accelerator pedal while letting the car move forward?)

That is a no-no for DCT.

Sometime when reaching red traffic light.

When using Eco mode, the gear likes free when release the accelerator petal.  No gear number was shown on the display.

Share this post


Link to post
Share on other sites

From D to R during parking, do you feel a jerk too? It comes randomly.

 

From 2 to 1 when slowing down to a traffic light, do you feel a jerk too?

 

From 2 to 1 when slowing down to a traffic light, before the jerk comes, do you hear a rattling sound too?

 

If the above are all true, then I know what's happening!

Feel the gear engagement when switch from D to R.  Doesn't feel like jerking.

From 2 to 1, can feel the gear change but not consider jerking.  No rattling sound heard.

Share this post


Link to post
Share on other sites

Hi all, thanks for sharing the information and opinion in the discussion.  I have some information to add on.

 

The service advisor/CnC did mention about DVR may cause the voltage/current unstable. Especially those low quality of dvr.  Initially, I don't buy his commend until I disconnected the dvr.  The situation of jerking reduced and until no more jerking.

 

But the problem occurred again after few weeks.  Now, I have disconnected all the USB device, dvr and Sharp ionizer.  Still un-solved.  Decided to send CnC for further diagnose on last Thursday, 20-Sep.  At the end, I cancel the appt as not single jerking from 17th to 20th.  

 

I'm afraid CnC not able to find any problem after send in and wasting my time.  Perhaps, have to monitor and wait until more serious issue.

 

Thanks again for all the feedback.

Share this post


Link to post
Share on other sites

That's it is good to find a independent WS to diagnose the problem as and when it crops up.

 

Diagnose = find the problem.

Share this post


Link to post
Share on other sites

Hi all, thanks for sharing the information and opinion in the discussion.  I have some information to add on.

 

The service advisor/CnC did mention about DVR may cause the voltage/current unstable. Especially those low quality of dvr.  Initially, I don't buy his commend until I disconnected the dvr.  The situation of jerking reduced and until no more jerking.

 

But the problem occurred again after few weeks.  Now, I have disconnected all the USB device, dvr and Sharp ionizer.  Still un-solved.  Decided to send CnC for further diagnose on last Thursday, 20-Sep.  At the end, I cancel the appt as not single jerking from 17th to 20th.  

 

I'm afraid CnC not able to find any problem after send in and wasting my time.  Perhaps, have to monitor and wait until more serious issue.

 

Thanks again for all the feedback.

 

Sometimes stuffs fails or become intermittent due to temperature (e.g. night, noon, rainy, traffic jam, etc )

Try to see if there is a pattern due to these conditions.  Also check for corrosion at battery terminals.

 

My experience with ionizers not related to automotive,  it can zap electronics.  Perhaps don't use it for the time being. 

Share this post


Link to post
Share on other sites

Bought S320 new from C&C in 2016 which is still under 7gtronics.

Sometime face gears jerking to engage but never in situation that i have to stop and off the car.

 

IMO - Merc 7G-tronics are not the best.

 

i did not raise the issue with C&C as i think it will be a waste of time. I believe its the issue on the gearbox technology.

i hope the 9-gtronics are better technology.

 

prefer BMW 8speed zf  gear and porsche gearbox comparing to Merc.

↡ Advertisement

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×