C63newdude

Folks,

I need your inputs. I did a pre-trade for a new Mercedes but I just can't pull the triga on a new car because I am reading the issues about the 7 speed transmission having to be replaced whenever the diff goes bad on the 4 matic.

I am very interested on buying a E550 sedan 4-matic but just the idea of having to replace the whole 7 speed transmission because of the Diff going bad makes me worry. I heard this topic about the GLK 4matic breaking the diff and having to replace the whole thing (transmission and diff) because the diff is inside.

Is this the same issue on the cLA 45 AMG? If this is an issue I might turn around and look for a RWD car.

spyked

Are you sure it's the diff?

All the reports and complaints I see are due to the internal transfer case on 7G Tronic 4MATIC.

The CLA won't have that problem - it's a FWD-based car. Totally different transmission and AWD set up. Not saying it won't have problems....but they won't be the same as the 7G Tronic 4MATIC on the RWD-based sedans and SUVs.

sleewell

I love my 4matic; wont ever buy another car without it.

Munich77

I would not worry about it - if this were such a big problem on the 4matics we would have heard about it by now. Remember they sell tons of 4matics.

C63newdude

My bad, you are right, the transfer case

C63newdude

Well, the problem is the amount of torque that the E550 puts. I plan to eventually get a tune if I get the car, that would put the car into a ridiculous amount of torque. That and the act that you can disable the traction it makes me think that something is going to give.

ImInPA

If you are this worried, then just buy a different car. Buying a car is supposed to be enjoyable. If you are already stressing, then this is obviously not the brand for you.

finman

My 14 E 550 performs great
no issues at all with the transmission

Arrie

Does E63 have a different transmission than E550?

Munich77

That is true that something has to give - although I have not heard of any blown transfer case due to a tune on an E550 or CLS550. Of course, there are not that many of those around. I do wonder how much the internals share with the transmission/transfer case in the E63 AMG. I suspect quite a bit....I would be more concerned about modifying a CLA 45 than an E550.

E Classy

E550 has a glob of torque already. how much more can you add (that would break the threshold)?

Arrie

No transfer case on these cars. It is differential, more precisely center differential. It is the differential that works between the front and rear axles just the same way as the differential on an axle works between the right and left wheel.

Transfer case is a part of the old fashioned 4-wheel drive that does not have the center differential. These 4-wheel drive vehicles are not supposed to be operated with 4-wheel drive engaged when driving on dry pavement where tire grip is good. 4-wheel drive is meant to be used on slippery surfaces where the tires don't have the best grip.

All Wheel Drive cars have center differential meaning that the front and rear axles are allowed to turn at different speeds as the center differential allows for this without stressing the power transmission parts too much. Well, MB may have a little problem here as they don't want you to have the staggered tires with the 4Matic obviously because this would cause a speed difference between the axles and wear on the "primitive" center differential lock, which I believe is a simple spring loaded "disk brake".

W210

All I can say is, I have heard faint ticking noise when accelerating from rest, had the transmission replaced twice already, just got the car back tonight.

Will see if the peace and silence will last.

martinlarose

I have reported recently that I have 20000 kms on my 2014 e 550 and it's been flawless...truly a great car

marvinlee

Staggered tires do not inevitably create an important speed differential. Check tire companies revolutions per mile data on their tires and select staggered sizes with similar turn numbers per mile.

usamuscle

Can you post something that is actually useful ? Instead of telling people they should get something else? . Lol , you did the same **** with me when I posted. Why even comment if you have nothing but bs to spew?
These are car forums , guys who ask car questions, some of which you may not like but they are asking because there is genuine interest. Not get another car.

instantfob

You can call it transfer case/center diff.

MB basically mated this unit into the 7G box and sell them as one for $7xxx. Makes it easier for dealer save time to "swap" things out.

ImInPA

Don't post ridiculous concerns if you don't want ridiculous answers. MB has sold millions of 4Matic vehicles. If you add up all of the complaints on these forums, it is a very small percentage of vehicles that(<1%) have any transmission issues at all. My response to you was a genuine "helpful" comment. If you are truly that worried about the 7G transmission then don't get a car with it. Period. If you are just a drama queen that needs to hear from others that it is a decent transmission, then, just buy the car. Your reaction to my comment tells me that you may not know very much about cars in general. If you think my advice about not buying a car that you have "serious concerns" about is BS, than you have a real dismal life outlook.

Tjdehya

I agree 100%.
I would have posted the same thing when I first saw this thread but I chose to ignore the thread instead.

Now that we are all being honest.
This is a DUMB thread.

C63newdude

^ This is not about you. Look at post number 13, he already replaced the transmission twice.

Arrie

No, this has nothing to do with center differential. I may have misunderstood the whole 4Matic construction as this tells me they use a simple "slip clutch" on the drive shaft to the rear axle to break or "slip" the mechanical connection between front and rear axles.

This also shows that any tire diameter difference between the axles will cause movement on this clutch that wears it over time.

It also says that these 4Matic cars are basically FWD cars with a "helper drive" at the rear wheels.

And now I see why Audi Quattro drive is so much better.


P.S. Found below Youtube and it really explain how the 4Matic powers the rear axle when needed, i.e. it is a FWD car with the RWD enabled when needed. This does not mean it is something bad. It just means it is a FWD car on good grip surfaces and here is where the staggered tire setup is a problem. With speed difference between the axles the system engages the rear axle, which then makes parts to wear as something has the give. Mostly this would probably show in very fast tire wear.

boltonblue

Arrie, I think that only refers to the new gen of little cars which are FWD by default.
The slightly older versions, like I've had all had open diffs and utilized the ABS wheel speed sensors and brake loading to balance slipping wheels.
I have a recollection that the current E has something similar to what you posted but in reverse whereas the front wheels are enabled when the rears are slipping.

Arrie

Don't know but they have a CLS driving in that video. And it clearly says rear axle is enabled only when needed.
Further, if you have a system that use brakes for "locks" like Audi Quattro system does you really need the center differential for true AWD functionality. By what the video shows MB 4Matic is NOT an AWD system as world knows these three letters mean. It is far from it.

E Classy

The CLA is a FWD architecture, so naturally that's the way it works for engaging AWD.

instantfob

A class 4matic system is for FWD platform cars A/B class.




C and above have the traditional Rear drive based 4Matic like the picture below