Hello. So I’ll try to summarize this with few words it’s a long story. I have a 2014 mercedes E550 4 matic. This summer I noticed I had some varying vibration which felt like engine mounts. In late September I decided to start with changing my tranny mount. After changing I noticed a slight vibration felt in the gas pedal (I know the gas pedal does not vibrate). I discarded it because I knew I needed engine mounts (put it on the lift, pulled the rubber, and they weren’t horrible but needed replaced). After getting the engine mounts replaced I noticed the vibration felt in the gas pedal was getting worse. It was very random (different speeds, temperature, certain roads, even same roads different times of day it would come and go). Took it back to the local mercedes shop who did the mounts and he suggested it could be a torque converter shutter. I have the 7G+ and know those are not as common as the previous 722.9 7G. We did another tranny service (the dealer did it this past summer) and notice the fluid was pretty black. Anyway, later in the day I noticed the vibration was back. Initially it was felt at higher speeds but eventually moved into lower speeds. Last weekend I was taking a sharp turn off an interstate on ramp (with an old mercedes tech friend of mine trying to show the vibration) and my front drive side CV axel popped out of the hub (outer CV axle). When we took it apart it there was no damage in the basket, the ***** were there, it was as if the axle just popped out. I asked the shop if they removed the axle to do the mounts and they said no, they took the exhaust out and bypassed the axle. Anyway my mercedes tech buddy and I bought a boot kit, and were sure this was going to fix the problem (because at times the vibration felt so strong like my axle was vibrating and was mostly felt in the gas pedal). Put it together and after driving for awhile the vibration is back. A couple of weird things I’ve noticed....

- when I let the car sit for a day or so then drive it’s minimal at first, but as the day goes on, the more I drive it’s gets much worse where it’s a constant horrible vibration.
- sometimes it’s random, and sometimes it’s constant vibration and lower and higher speeds (higher speeds are worse)
- it’s ALWAYS felt in the gas pedal and floor (right under my feet), never in the steering wheel.

Any help is much appreciated!

 

Have you check if your wheels are bent?

 

yes sir. had new tires put on early this summer with new wheels. The car was riding like a dream before all this crap. All started with the engine/tranny mount replacement.

 

Did you buy it new? Only reason for the question is whether the axle is new or not. If it just fell out, I wonder if it's an aftermarket. The aftermarket ones are known to cause a vibration if they're not good ones. Probably should take a closer look to see if it's OEM or not. If it isn't, I would suggest a used one from a junkyard or get one that is rebuilt. I wouldn't trust a new one.

Also describe the vibration a little more specifically. Is it there when the car is stopped? Do you notice it when the car is in park vs in drive?

 

Hi cetialpha5. I bought the car used but the axle was the original OEM, still had the sticker on it. Since the vibration was there prior and after the boot was replaced I’m wondering if the axle falling out is the symptom of something causing this vibration?

 

Well you're probably going to have to check a bunch of other stuff then. Driveline, bearing support, etc. Might help to put it on a lift and start it up and see what parts underneath are vibrating. These types of problems are hard to diagnose online.

 

That is the plan this weekend to put it up on the lift and drive it. I’m hoping it’s not a torque converter shutter, I’ll sell the car. Thanks

 

Good luck with it, you have one of the rare last E550's made for the US market. Be a shame to just dump it.

 

I agree, love the car! Thank you.

 

Two things come mind.

1) flex couplings on the driveshaft ends. They do wear out, will get hairline cracks and are known to cause weird vibration issues. How many miles? And with the V8, more torque going through the shaft.

2) drive shafts just don’t pop out like that. Somebody messed with it. When my motor mounts were changed, the front driveshaft had to come out to get it done. My mechanic is a multi-decade MB mechanic and has personally owned a 212 like ours. Knows them like the back of his hand, and said the process involves removal of the axle to get to one of them.

2a) removal of the front driveshaft is the process to replace the front diff fluid. Since yours came out, I am curious how your front diff fluid is? Maybe that’s what caused it to come out in the first place - someone tried to change it in the past and didn’t put it back together with proper torque of the bolts?

 

Hi nc211 thank you for your response! So the car just past 103,000 miles. I drive a lot. That’s why on long days it’s strange that by the end of day with a lot of driving the vibration gets much worse, and is only felt in the gas pedal or under my feet (near the front diff right). So the flex discs I checked and did not see any cracking but I know they are made of rubber and can wear out so we will definitely check those.

I agree with you about the cv axle. The shop told me they took the exhaust out, and steering column and did I not have to remove the axle but I can clearly see where bolts were removed. Also they did also supposedly drain my diff fluid I just wish I could prove something.

 

MB procedure to fill the diff is removing the axle... so there you go. They could fill it by pumping up thru the drain plug. Then, they aren’t following their own procedures.

*edit* at least on earlier w212


Popping out of the hub side would indicate they forgot to secure the axle nut.

 

And those axle nut bolts are supposed to be one time use bolts, but I've reused mine before. That's why the MB boot kits come with the axle bolt.

 

Thanks for the response. So that is what is very strange, when I pulled the axle out it wasn’t damaged, the axle nut bolt was still tight, even the boot basket was in good working shape with all the *****. All the bolts were tight it just literally looked like the it disconnected. Do you guys know how much play you should have with your front drive shaft (going from the tranny to the differential). When I move my tire back and forth it has a decent amount of play but not sure what the threshold is?

 

I’m sorry, but what your saying doesn’t make sense...

The axle nut was tight, yet the axle popped out from the hub? Was the nut cross-threaded and not tighten down all the way? That would allow the axle to slide on the splines.

I guess I’m confused about the “pop out”. Now I’m thinking the CV joint came apart. No way it was “fine” as you mentioned and referenced a “basket” and “*****”...

 

Let me attached some pics. Maybe I'm using the wrong terminology....

 

Hello again everyone. Just an update and any new advise would be great! We rebuilt the boots on that front driver side axle (see pictures). Vibration is still there. So put the car up on the lift and drove it while I looked underneath. Front right tire looked like it was wobbling ever-so-slightly. So changed front passengers side axle (opposite the side where the axle popped out). Vibration got worse after replacement where the whole axle is wobbling and shaking the whole front of the car.

Something is causing both of my front axles to have very strange issues (front left popping out clean. Front right wobbling after new replacement). The vibration is always felt in the gas pedal (even though I know it’s not, it’s a drive by wire), and down on the floor almost behind, and down from my radio (right where my tranny meets the oil pan, and diff).

I’m thinking my intermediate axel has to be bad (the one running through my oil pan and differential). Or the bearings in there are bad. Seems if this was the case though bad bearings make a very bad noice. I even put a stethoscope on the differential while it was being driven on the lift and did not hear anything crazy, a little grinding maybe....

All your thoughts, experience, and expertise is greatly appreciated!

 

That outer joint looks destroyed... the splined end of the shaft has separated from the inner race. Usually they have a circlip, did you forget to install or lock into place? I don't think rebooting it is an option. As far as the "new" axle, where did you source it from?