Balance shaft sprocket M272/M273

jbanks15 · Nov 24, 2013

Applicable Models (Not Applicable to Model 164.156, 204 or 216.386): Equipped with M272 Engine Up to
Serial No. 2729..30 468993
or M273 Engine Up to Serial No. 2739..30 088611.
The material for the balance shaft sprocket and the timing chain guide wheel (idler) was modified on
engines past the serial numbers listed above.

the ... represents 'any number'

Courtesy Efair

Added by jbanks15:
Balance Shaft Gear Issues
M272 engines that were sold between 2004 and 2008 with engine serial numbers below 2729..30 468993 often show early wear of the balance shaft gears, requiring extensive repairs at a retail cost of over $4000. These complaints led to a class action lawsuit against Mercedes Benz (Greg Suddreth and Paul Dunton v. Mercedes-Benz USA, LLC), which alleged the M272 engines are equipped with defective balance shafts gears which "wear out prematurely, excessively and without warning, purportedly causing the vehicles to malfunction, the check engine light to illuminate and the vehicle to misfire and/or stop driving." The suit further alleged that Mercedes knew of this problem, sending out repair bulletins on how to address this issue and ultimately changing the balance shaft gears to avoid this problem. This suit was ultimately dismissed with the judge agreeing with Mercedes that because the gears fail at 60 -80K miles and outside of the warranty period, Mercedes is not legally responsible for these problems. A second class action lawsuit is being organized. [7]
7. "Mercedes Benz named in class action over safety issues related to its M272 or M273 engines". Retrieved Mar 12, 2013.
http://gotaclassaction.com/mercedes...z-named-in-class-action-over-safety-issues-related-to-its-m272-or-m273-engines/

**
Do the video test to see if you have the issue, posts 106 and 117 and here
from Michael H.

Video: Check your Balance Shaft Sprocket in 10 minutes.

**
Easy Balance Shaft Check from Brad Wessels here:

Easy Balance Shaft Check Revisited
*
From Lil Don Slk

**
Check your engine number in your free datacard:

FREE!! How to get a free datacard!
**
Here are sister threads on this issue:
Balance Shaft Sprocket

more balanceshaft questions for the pros!

M272 Engine : Fast and Simple Detection of Balance Shaft Failure

Here is Notice of Pendency and Proposed Settlement of Class Action attached
see last pages of this thread for discussion
***
The Balance Shaft/Idle Sprocket settlement was approved by the court
post 156
Read the court document Class Action Settlement Claim Form - PreMail
****

George_in_KG said:
FCPEuro is my first choice for on-line MB and Volvo parts. They just published this guide for common problems with the M272/273 engines and I thought everyone here would find it interesting. It is a nice summary of many topics that are covered here on slkworld.

The Definitive Guide To The Mercedes-Benz M272 And M273 Engines - Common Failure Symptoms and Diagnosis

..

Courtesy of @Ad B

Data from a member of a UK forum:
engines up to #2729..30 468933 -- this when the gear is the problem
engines up to #2729..30 759427 -- this when the adjustment solenoids are the problem
engines up to #2729..30 895140 -- this when the adjustment solenoids leak oil

Akonion · Dec 8, 2013

My engine (272963 30 003441) seems to fall within the range. If I were to encounter balance shaft issues what would the symptoms be, and what could I do to be proactive against it?

bac · Dec 8, 2013

Often there are no major symptoms until the CEL comes on. If you have STAR, you can periodically check for codes relating to cam bank timing issues. Other than that there is the visual inspection technique for checking the cam bank timing marks are still aligned (search on here for link to video).

Not much you can do to be proactive about it - if it's going to happen, it's going to happen.

Cheers,
Brian

efair · Dec 10, 2013

My invoice shows the balance shaft kit at $465 USD. Motor mounts, head gaskets, intake gasket, tensioner, breather cover, cam sensors, cam actuators, and fluids brings the parts tally up significantly though -- to about $1400.

Ben535 · Dec 23, 2013

jbanks15 said:
Applicable Models (Not Applicable to Model 164.156, 204 or 216.386): Equipped with M272 Engine Up to
Serial No. 2729..30 468993 or M273 Engine Up to Serial No. 2739..30 088611.
The material for the balance shaft sprocket and the timing chain guide wheel (idler) was modified on
engines past the serial numbers listed above.

Courtesy Efair

Hi, since what model year could we say this issue was resolved? I am looking to buy a used one and it would be easier for my search.
Thanks!

jbanks15 · Dec 23, 2013

see the reply by Woolly in your other post. Oil was usually 2005 and sprocket 2006-8

journeyman · Jan 27, 2014

Found this amateur video showing exactly what a worn balance shaft looks like and its location within the engine. Also gives tips on repairing the job yourselves... yeah, good luck.

RobHufton · May 14, 2014

SLK 280 Balance Shaft Problem

Are there any other people on here in the UK that has had this issue?

I have recently purchased an SLK 280 and have now been told that balance shaft needs replacing at a cost of £5000+

Car is 2007 and only 22,000 miles

Repair represents almost half the cost of the car :-(

Rob

mchild · May 15, 2014

RobHufton said:
Are there any other people on here in the UK that has had this issue?

I have recently purchased an SLK 280 and have now been told that balance shaft needs replacing at a cost of £5000+

Car is 2007 and only 22,000 miles

Repair represents almost half the cost of the car :-(

Rob

Seems like very low mileage for this to be showing up. What are the symptoms and what has been done to confirm the problem? Is a second opinion warranted? Since you just recently purchased the car does the seller share any obligation here?

bac · May 14, 2014

Very sorry to hear it! Would have thought it quite unlucky to strike this problem on a 2007 car...

Have you tried approaching Mercedes directly for a goodwill gesture given the very low mileage and the fact that it's a well known problem?

Hope things eventually turn out OK.

Cheers,
Brian

RobHufton · May 15, 2014

bac said:
Very sorry to hear it! Would have thought it quite unlucky to strike this problem on a 2007 car...

Have you tried approaching Mercedes directly for a goodwill gesture given the very low mileage and the fact that it's a well known problem?

Hope things eventually turn out OK.

Cheers,
Brian

Thanks very much Brian,

I have asked my local MB service manager to ask MB if there is a possibility of contribution towards this known problem, but he does not hold out much hope as car is more than 6 years old :-(

Regards,

Rob

Sandtoes · Jul 7, 2014

Different Part Number for improved part?

Wife drove home today from running an errand, describing the rough running and CEL that came on - I fear the sprocket issue is saying, "Hello!" Our SLK350 has about 41,000+ miles.We'll be taking it in tomorrow.

Didn't have luck searching but I apologize if this is answered already...what I'm curious about is did Mercedes come out with an improved sprocket to replace the problematic one? Is there a part number revision from the old part number that confirms there is a change? Just would like to know if this is going to become a "regular replacement part" to be aware of, or the fix is a long term/permanent solution.

journeyman · Jul 8, 2014

Sandtoes said:
Just would like to know if this is going to become a "regular replacement part" to be aware of, or the fix is a long term/permanent solution.

It seems only Mercedes knows the statistics on this sprocket failure. The teeth wear occurrence is sporatic; I've found the mileage range to be from 20k-120k. How are some cars having this issue at only 20k miles?

My trusty mechanic says if you use a good oil (not Mobil 1), and change your oil every 5k miles, you will not see this sprocket wear problem. The main goal for engine oil is to prevent wear of the internal metal parts. There is a reason why Mercedes updated the oil change interval from 12k miles to 5-6k miles.

jbanks15 · Jul 7, 2014

per efair's post above:

My invoice shows the balance shaft kit at $465 USD. Motor mounts, head gaskets, intake gasket, tensioner, breather cover, cam sensors, cam actuators, and fluids brings the parts tally up significantly though -- to about $1400.

so i think it would be the parts kit n not just the sprocket.

i checked epc and there is no new 'shaft/sprocket' replacement number i can find

Sandtoes · Jul 7, 2014

Ooo man, that doesn't give me the warm fuzzies. I'll give up thinking about it until tomorrow - no sense in wasting the last hours of a long holiday weekend dwelling on it. Jeff - your powers of replying to all these posts - amazing! Thanks!

efair · Jul 7, 2014

Don't panic -- the balance shaft symptoms aren't "sudden onset" like this; plus there are specific codes for the problem. Have your codes read and cleared for free -- most parts places offer this service (just be sure you write them down before they're cleared). Let us know what they are.

72 dudes · Jul 8, 2014

I wondered this, but difficult to say that the fault was present at time of purchase, even though SOGA relies on seller to prove that the fault was NOT present at time of purchase - only applies if seller was a motor trader.

But I seem to recall that Rob bought his car privately?

efair · Jul 8, 2014

journeyman,

What is a good oil (Not Mobil 1)?

My suspicion on why some fail and some don't is this: the sprockets were produced in multiple foundries, some foundries produced worse products than others. Just a guess though, I have no inside information.

journeyman · Jul 9, 2014

efair said:
journeyman,

What is a good oil (Not Mobil 1)?

Beekster said:
Mobil 1 is the factory fill, so Mercedes-Benz must be satisfied with it.

The only thing Mercedes was satisfied with was the large sum of money Mobil 1 paid them to sponser the oil in their engine bay. Now that problems like this sprocket issue arise, Mercedes said to change oil at every 5k miles instead of 12k. RedLine oil is a safer bet at going 12k miles before a change because it has a much higher TBN (total base number) than the Mobil 1 0w-40, but I still change mine at every 5k-6k.

Red Line is an ester oil rated for "off-road use only" because it bypasses itself from having to follow EPA's regulations for restricting engine oil of its most valuable additives, so we can help our beautiful Earth from blowing up in on itself and turning into a black hole due to our Styrofoam and carbon monoxide. RedLine oil is used in aircraft. Motul also makes a very good ester oil, my mechanic said Motul is better than RedLine.

Maybe I put too much faith in my mechanic. Much of the stuff he has told me though I was able to verify online.

Beekster · Jul 8, 2014

Mobil 1 is the factory fill, so Mercedes-Benz must be satisfied with it...

The balance shaft sprocket problem was traced to improper heat treatment of the part by a vendor for certain batches of parts. That is why the problem persisted for a relatively long time. The fact that it was intermittent and not on all batches is likely traceable to human error; a couple of people not following the procedure correctly...especially if they were behind schedule on the parts and wanted to catch up.

72 dudes · Jul 11, 2014

Well, I sure hope Herr Glockenspiel at the supplier was having a good day when he made mine!

Sandtoes · Jul 9, 2014

Well, picked up the car today (side note: realized we don't have a nick-name for our SLK).
Codes read by the shop showed a misfire. But, of course its a gremlin - the CEL is gone and the car ran fine during the time spent in the shop. Shop swapped ignition coils and even plugs, but could not re-create the misfire.

efair · Jul 9, 2014

I guess that's good news...

efair · Jul 10, 2014

Thanks journeyman, good info that led me to do a little reading. I'm not convinced yet that a different oil, and/or a more frequent change interval, would mitigate the premature balance shaft wear. If that's what you're saying please explain!

Beekster · Jul 10, 2014

I don't think anything will mitigate the wear problem, efair. It is a function of improper heat treatment, so the metal itself does not possess the hardness specified on the engineering drawing that went to the vendor. If the metal does not possess the material properties it ought to have according to the engineering specifications, it will wear improperly regardless of the oil being of good, bad, or indifferent quality or how often it is changed. In short, if the part is bad because of poor quality control on the part of the vendor then it's only a matter of time before it fails.

But like you I'd be interested in journeyman's thoughts on oil quality making a difference. But he'll have a hard time convincing me he's right.

allanrbaird · Sep 8, 2014

My engine number is 272963 30 080036.

It looks like I am at the tail end of the bad sprockets. the dealer I bought the car from says the following: "they need to check the timing which will take about 3 hours, they feel like the solenoids are the problem. they believe the solenoids fail causing the rods to break."

After the last time they worked on it the cel went on about 10 minutes after I got the car back. Then it went off for 10-15 minutes then came back on. It has been on since then. Does what they are telling me make sense?

efair · Sep 8, 2014

No, it's total nonsense.

Kwaka · Oct 13, 2014

I've just bought an SLK 350 2005, that's done 43k miles. The engine number is 272 963 30 014400, so I guess mine is in the bad batch?

Is it worth me trying to reject the car with the dealer even though nothing is wrong with it?
It's due back in for a service with MB this week.

mchild · Oct 13, 2014

Kwaka said:
I've just bought an SLK 350 2005, that's done 43k miles. The engine number is 272 963 30 014400, so I guess mine is in the bad batch?
Is it worth me trying to reject the car with the dealer even though nothing is wrong with it?
It's due back in for a service with MB this week.

There is a simple procedure that allows you to align things so that if there is excessive wear starting to happen it can be detected. It takes about 15 minutes to do. If it were my car I would either do the procedure myself (I did) or have the MB dealer do it and show you the results so you can be comfortable with this car or start discussing with them the return of the car.

Having said that, your engine number is low enough that I am guessing your car may have been built in 2004. From what I have heard not only are few SLK's affected by this problem but the very early ones (built in 2004) have not been showing up with the issue. If your car was built in 2005, it may be a little higher chance that you may have an issue down the road.

jbanks15 · Oct 13, 2014

Several things to consider.

it might have been fixed by previous owner. It might never have occurred. It might never occur.

My previous 05 350 was on the list and had it new and never had any issue.

marktrue · Oct 15, 2014

My car is in the effected range and it just turned over 75,000 miles.

To the best of my knowledge and research, only 10% of engines ever develop the problem. And of those, most are in the heavier cars, like the GL. SLK very rarely develop the problem.

I came to the conclusion that I love my car, and stopped worrying about it. if it happens, I'll fix it as there is no car I would rather have than my SLK.

Enjoy your car and don't worry about it.

Kwaka · Oct 19, 2014

marktrue said:
My car is in the effected range and it just turned over 75,000 miles.
To the best of my knowledge and research, only 10% of engines ever develop the problem. And of those, most are in the heavier cars, like the GL. SLK very rarely develop the problem.
I came to the conclusion that I love my car, and stopped worrying about it. if it happens, I'll fix it as there is no car I would rather have than my SLK.
Enjoy your car and don't worry about it.

I pretty much got the same advice from my MB technician when it went in for a service last week. He said there's no signs of swarf in the oil anyway and said not to worry about it. So that's what I'm doing, enjoying the car. If it goes wrong it goes wrong and that's that.

DSSG · Oct 24, 2014

Can anyone tell me how to decode the engine serial number? Specifically the two numbers that precede the final six digits, the serial number? On the site they are 30.

BTW, I was able to obtain the engine serial number from my dealer.

Thanks

Sneaky Pete · Oct 25, 2014

DSSG said:
Can anyone tell me how to decode the engine serial number? Specifically the two numbers that precede the final six digits, the serial number? On the site they are 30.

BTW, I was able to obtain the engine serial number from my dealer.

Thanks

As I understand (not 100 % sure) these 2 numbers designate the production plant of the engine. I believe (again not 100 % sure) 30 stands for Untertürkheim. So only the final six are of interest.

jbanks15 · Oct 24, 2014

Your engine serial number is in your datacard if you requested one from us free

ted · Oct 26, 2014

Just had a look through all the reciepts that came with my car and there is one for this job being done in june 2013 for £1544 after a 50% discount from mercedes. Work was carried out at the supplying dealer where it has also always been seviced and mot'd. So at least a bit of financial help was given.

Beekster · Oct 26, 2014

Then you're good to go! Once fixed this issue does not reoccur, since the new parts have been properly heat-treated. Keep the car serviced according to the manual, and you can expect another couple of hundred thousand miles out of it at the very least.

Balance shaft sprocket M272/M273

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