7g transmission failure rates C250 Bluetec

Page may contain affiliate links. Please see terms for details.

Animal

Member
Joined
Oct 8, 2014
Messages
46
Car
S205 C250d Bluetec Sport Premium Plus, Est
What is the general reliability of the 7G transmission?
my 2014 S205 C250 Bluetec has been having issues for a few months now, in and out of what appears to be limp mode, EML occasionally coming on and no fault codes (Star).
During diagnostics there were some references to issues with the lock up clutch and a selection range valve on the conductor plate.
After first visit to the Indy they suggested an update and thought that had cured it.. It had not. More symptoms then started, the engine was also surging when accelerating underload, it also stalled when coming to a stop.
I managed to book car for a more thorough examination, Indy initially was thinking the torque converter and valve might need replacing but that didn't cure it either.
Further examination showed lots of metal shavings in the gearbox, I have been advised that an exchange gearbox from Mercedes is the answer!
All parts including torque converter etc £4.5k plus vat.
This car has covered 62k miles, I mean WTF!
What are peoples experiences with this gearbox?
 
What is the general reliability of the 7G transmission?
my 2014 S205 C250 Bluetec has been having issues for a few months now, in and out of what appears to be limp mode, EML occasionally coming on and no fault codes (Star).
During diagnostics there were some references to issues with the lock up clutch and a selection range valve on the conductor plate.
After first visit to the Indy they suggested an update and thought that had cured it.. It had not. More symptoms then started, the engine was also surging when accelerating underload, it also stalled when coming to a stop.
I managed to book car for a more thorough examination, Indy initially was thinking the torque converter and valve might need replacing but that didn't cure it either.
Further examination showed lots of metal shavings in the gearbox, I have been advised that an exchange gearbox from Mercedes is the answer!
All parts including torque converter etc £4.5k plus vat.
This car has covered 62k miles, I mean WTF!
What are peoples experiences with this gearbox?
I think you are 7g+ , my 7g is on 118k with never an issue
 
My 7G is on 143'000 Mils, still sweet. Recently changed the oil and filter, nothing untoward in the sump or on the magnets, so fingers crossed for the next 142'000 Miles.
 
Has it had the transmission fluid replaced?

My 320 CDI with a 7G gearbox has covered 160k and is smooth running and it handles a lot more torque than in a 250 CDI
 
What is the general reliability of the 7G transmission?....?

With respect OP , your question to us is a bit redundant as it would appear that your transmission is toast. Why ? , where ? and how ? is not really the issue in your case. It's fooked . The question now is how you move forward.

The world is full of MB Taxis with the same transmission running on stellar mileage with the correct servicing.

Not sure what you mean by this "Indy initially was 'thinking' the torque converter and valve might need replacing but that didn't cure it either. " Did your just Indy 'think ' about replacing these parts ? or actually replace them ?

A bit more detail might help us to help you.

PS , if you buy a new transmission or get yours repaired remember to flush out or replace the cooling lines/radiator.
 
Metal shavings in the gearbox is terminal. Looks like you've been unlucky. Looks like something was starting to happen a few months ago and its just got worse. Was it low on fluid?
If it is replaced, as said above, everything needs to be flushed within an inch of its life - there needs to be no possibility of any metal particles being left behind, otherwise it will just happen again.
 
Buy and fit a used replacement gearbox, have them swap over your control unit while replacing filter etc before filling it. That's surely going to be more cost effective.
But back to the original question..... No, it's not that common. These gearboxes do ask for more regular servicing than other brands, but generally seem quite capable of skipping a few services without drama.
 
As I've just bought a 31,000 mile 2016 W205 with the 7 speed auto I have found out that the next service due should include changing the transmission oil and filter. I plan to do all my own servicing, though this job looks like it might be difficult for access without a proper car lift, so I might have to take it to a local Indy. Does anyone have a rough idea of costs for getting this done?

Parts (Eurocar parts prices) seem to be about £70, plus the oil ,not sure how many litres needed and the exact spec required yet as I haven't looked too far into it once I watched a video of it being done.

My only concern would be that it is properly drained out as I understand the torque convertor contains about 4 litres of oil, so that needs to be drained as well (possible shortcut if not?). I do wonder whether my work C Class cars actually had this done, not that I ever had any problems with the 7G or 9G gearboxes in them, but I know the Lease company would cut corners if they had the chance.
 
As I've just bought a 31,000 mile 2016 W205 with the 7 speed auto I have found out that the next service due should include changing the transmission oil and filter. I plan to do all my own servicing, though this job looks like it might be difficult for access without a proper car lift, so I might have to take it to a local Indy. Does anyone have a rough idea of costs for getting this done?

Parts (Eurocar parts prices) seem to be about £70, plus the oil ,not sure how many litres needed and the exact spec required yet as I haven't looked too far into it once I watched a video of it being done.

My only concern would be that it is properly drained out as I understand the torque convertor contains about 4 litres of oil, so that needs to be drained as well (possible shortcut if not?). I do wonder whether my work C Class cars actually had this done, not that I ever had any problems with the 7G or 9G gearboxes in them, but I know the Lease company would cut corners if they had the chance.
I would suggest that it is not really a DIY job. As say, access is difficult without a lift.

As for ECP, I would be wary about their knowledge when it comes to the correct fluid specification etc.

I am unsure about the transmission in your vehicle but most MB units usually hold around 8 litres. Some Independents do not drain the Torque converter (not all TC units have a separate drain plug), as for cost, my 7 speed transmission cost £200 about 4 years ago and I am sure prices will have risen.

I would highly recommend PCS at Horndean near Portsmouth. They are not local to me (circa 50 miles) but I found them to be a very professional team who are renowned for their excellent work.

I booked my car in for 08:30, went off to have breakfast and it was ready just after 10am 👍
 
Excellent info @DSM10000 though I wouldn't rely on ECP for the oil information I'd research that elsewhere first. However, just for pricing information they are listing a 4 litre ATF for £68 total parts costs would be £140 ish. Therefore an extra £60 or so on top for the price you paid (albeit 4 years ago) seems worth paying to have it done. Not sure I'd want to have to get to Horndean for 8:30 though...maybe they do afternoon bookings. :D

There are Merc specialists near me, though I've not had reason to use them previously due to company cars and my wife had an MB service contract on the SLK we used to have, so I didn't need to do much to it. All useful info though thank you.
 
Excellent info @DSM10000 though I wouldn't rely on ECP for the oil information I'd research that elsewhere first. However, just for pricing information they are listing a 4 litre ATF for £68 total parts costs would be £140 ish. Therefore an extra £60 or so on top for the price you paid (albeit 4 years ago) seems worth paying to have it done. Not sure I'd want to have to get to Horndean for 8:30 though...maybe they do afternoon bookings. :D

There are Merc specialists near me, though I've not had reason to use them previously due to company cars and my wife had an MB service contract on the SLK we used to have, so I didn't need to do much to it. All useful info though thank you.
I recently had the gearbox service done on a B180 for £250 at a Mercedes independent in Glasgow. I do most of my own servicing and repairs but, like you, decided this one was beyond me.
 
Excellent info @DSM10000 though I wouldn't rely on ECP for the oil information I'd research that elsewhere first. However, just for pricing information they are listing a 4 litre ATF for £68 total parts costs would be £140 ish. Therefore an extra £60 or so on top for the price you paid (albeit 4 years ago) seems worth paying to have it done. Not sure I'd want to have to get to Horndean for 8:30 though...maybe they do afternoon bookings. :D

There are Merc specialists near me, though I've not had reason to use them previously due to company cars and my wife had an MB service contract on the SLK we used to have, so I didn't need to do much to it. All useful info though thank you.
Give Ian @ Star Services, Caversham,Reading a ring he is an MB specialist.
 
What is the general reliability of the 7G transmission?
my 2014 S205 C250 Bluetec has been having issues for a few months now, in and out of what appears to be limp mode, EML occasionally coming on and no fault codes (Star).
During diagnostics there were some references to issues with the lock up clutch and a selection range valve on the conductor plate.
After first visit to the Indy they suggested an update and thought that had cured it.. It had not. More symptoms then started, the engine was also surging when accelerating underload, it also stalled when coming to a stop.
I managed to book car for a more thorough examination, Indy initially was thinking the torque converter and valve might need replacing but that didn't cure it either.
Further examination showed lots of metal shavings in the gearbox, I have been advised that an exchange gearbox from Mercedes is the answer!
All parts including torque converter etc £4.5k plus vat.
This car has covered 62k miles, I mean WTF!
What are peoples experiences with this gearbox?
I had probs with my gearbox...(e63 bi turbo) Different to yours though...think i caused the initial fault when brakes were jammed but could just be coincidence.... Anyway needed replacement box....eventhough no metal fillings in the oil....internal main drivetrian was all damaged.... Wasnt throwing up any codes as well. Did alot of research and took a punt on 15,000 s63 box... Which i bought for £800.. Wayne gates fitted it and necessary coding etc and also advised to change wet clutch as well... Wayne gates also did a service on my car as well... Wasn't cheap BUT would have cost alot more getting recon box etc
Main issue is some garages dont want to commit to suggesting what boxes will fit... From other mercs as they dont want any comeback and so i done alot of research myself and asked forum members .... Box came with 3 months warranty as well.... All good at the moment and happy it worked out.. good luck on what you decide
 
As I've just bought a 31,000 mile 2016 W205 with the 7 speed auto I have found out that the next service due should include changing the transmission oil and filter. I plan to do all my own servicing, though this job looks like it might be difficult for access without a proper car lift, so I might have to take it to a local Indy. Does anyone have a rough idea of costs for getting this done?

Parts (Eurocar parts prices) seem to be about £70, plus the oil ,not sure how many litres needed and the exact spec required yet as I haven't looked too far into it once I watched a video of it being done.

My only concern would be that it is properly drained out as I understand the torque convertor contains about 4 litres of oil, so that needs to be drained as well (possible shortcut if not?). I do wonder whether my work C Class cars actually had this done, not that I ever had any problems with the 7G or 9G gearboxes in them, but I know the Lease company would cut corners if they had the chance.
Cost me £155 in parts to do mine, if you can get it done using genuine parts for £250 then its a bargain,
You can see here the parts you need if you fancy DIY.
To view this content we will need your consent to set third party cookies.
For more detailed information, see our cookies page.
 

Users who are viewing this thread

Back
Top Bottom