ABS Tone Ring
 

https://cimg5.ibsrv.net/gimg/www.mbw...14bb4e54a2.jpg
I have been having the ABS/ ESP/ Tire pressure warning Message coming up on my dash for the last week.
I have an MB2 Scanner ( worth the $200 I paid for it ) that told me the problem was the right rear speed
of Wheel Axel was off. I had just replaced the Wheel Sensor 3 Months ago and was thinking it might be, I had gotten a Bad Sensor.
It turned out to be the tone ring. Lots of stuff on the web about replacing axels @ big $$$$ and im not saying that might not be the problem for other people.
If you need to replace the Tone Ring the part number from MB is - 230-357-01-82 The picture above is of the Ring that came off my 2007 S550 / 4Matic.
I hope the above helps out if you have a problem like mine.
BTW: The Ring was $22.00 Canadian Dollars.

Hmm, I recently got a error like this where the NAV and the rear sensor had a delta between them. The alarm was cleared but did not come back.

Just an update:
I have been away with the car and have put 1300 kms on from having the tone ring replaced.
Im happy to report everything is still fine. I Also find the Tone Ring goes by the Name "Reluctor Wheel" just in case you see it listed on the internet with that term being used.
ABS / ESP / TIRE All fine and no Warning Messages in the Dash.

Looking at diagrams it appears the axle needs to come out to replace. Am I following this correctly? Cheap part, but expensive fix?

The Axle does come out of the car.
Total time was 4.5 Hours,
Tone Ring goes on easy.

Reverse Torque Nuts
 

I had my 2007 S550 4Matic in to my local mechanic to have the reluctor ring replaced. He believed he had to remove the reverse torque nuts. None of his tools fit. Do you know if it is a special socket or such, or do you not need to remove the torque nuts? Thanks very much Ed

I am not sure about your Torque nut question. may understanding is, all you have to do is roll the knuckle out of the way so you have room to work.
This set up is a lot like the Chrysler 300's

Your mechanic is going to have to buy the correct size eTorx socket.

Thank you for getting back to me. I was wondering if you need to remove the torque nuts or does the whole assembly pull off? The issue he had was that all the torque sockets he had were to deep too fit in the small space with the ratchet. I was not there so I do not know what he removed, but he is pretty good and would have tried a couple things before giving up. He could get on the torque nut, but he was on such and angle he was afraid of rounding them. The picture here shows the pulling off of the hub, but I do not see anything about removing the torque nuts first.
[img=left]https://cimg7.ibsrv.net/gimg/www.mbworld.org-vbulletin/960x720/5_f41e4102b0a6de62f39b7557e20278f5c21280d8.jpg[/img]

Thanks for the reply. He had two or three that were the correct size for the nut but he could not fit them in the tight area. Ed

Difficulty in replacing tone ring (reluctor ring)
 

I realize this an old thread but I'm hoping you'll still see my post. I have a 2009 S450 4matic which had an error for the front right wheel speed sensor. When I went to replace it, the the sensor broke off and after trying various "tricks" I had resort to trying to drill it out. To do it right, however, and to make sure that I didn't damage the reluctor ring I decided that I should remove the knuckle and try to drill/tap out the remnants of the sensor. That was last summer and I never got around to it. I'd like to tackle the job now, and I'm am speculating that I might have to remove and replace the reluctor ring. My question to you is how hard was it to the the old ring out and from where did you buy the new ring? I see you are or were in Nova Scotia. I am now in New Brunswick and the dealership in Moncton is a joke. I brought my GL into them last year for a brake booster recall, and not only did they completely destroy the braking system, somehow they managed to destroy the air suspension. When I picked up the GL, it was on all 4s and the pedal traveled right down to the floor. But I digress...

Hello, I had my car fixed at the local Chrysler Dealership, This system used on the W221 is very close to what was on the Chrysler 300's back in the day.
I still have my W221 and i have not had a problem with it anymore

Um ok. Thanks for the reply.

on 2WD version the front reluctor ring is part of the inner oil seal for the front wheel bearing, its a typical Merc idea. on the 4x4 ones the parts doc doesn't seem to show it

https://nemigaparts.com/cat_spares/e...221086/63w/33/

Thanks Botus. Yes, I've been looking for it just in case I need it, but I can't find a part number anywhere. I'm thinking it might be part of the axle, but I won't know until I get back in there. There isn't a whole lot of info of S Class' in general and basically nothing on this. I'm hoping that once I take the knuckle off, I'll be able to get a look at the ring to make sure it's not damaged in any way. I just don't like to be caught without a part I might need. Thanks again, and if you'd like to know what I find, let me know and I'll post an update.

whats the round bit here...

RS Collar 2213300285

https://cdn1.pelicanparts.com/catalo...2-85-MBZ_1.jpg

better idea go to the parts dept and ask - the specialists in what bits you can buy and what it is, is the parts guy at your main merc franchised dealership

Unfortunately, we moved to a small place in eastern Canada and there's only one dealership here. They are not only idiots, they are first rate rip off artists. I had a choice of dealers in Toronto, but they were all pretty good. Expensive, but at least they knew what they were doing. So, getting any advice from the local dealer is a non-starter for me. As far as the image from Pelican that you uploaded my guess is that the ring appears to be a seal for the outer cv boot.
https://classicparts.mbusa.com/oem-p...Y4LWdhcw%3D%3Dhttps://cimg0.ibsrv.net/gimg/www.mbw...337ce9b861.png

I'm going to get the knuckle off in the next week or so and I'll post an update with what I find. I didn't drill down very far in trying to get the bits of the speed sensor out, so I really doubt that I damaged the tone ring.

as per post #1 if they used that idea its normal to corrode and fall off

the rear is like that - I wonder if its the same bit for the front ?

https://nemigaparts.com/cat_spares/e...86/63w/35/030/

Part 120 IMPULSE RING LEFT 001 A 23 035 701 82 - $10.82

I can't find anything for the front. If you look at that part number on any online mercedes parts store, it's only for the rear. If you google any diy instructions or youtube videos, it's only for the rear axle. Hang tight...I'll try to solve this mystery next week.

If this is a 4Matic and the front, the tone ring is built into the bearing that the hub inserts into.

Thanks EasyPhil. Yes, it is a 4Matic and it's the front passenger side where the wheel speed sensor got stuck and broke. I was going to remove the knuckle so that I can clean it out on the workbench. If there's no damage to the ring, then I won't need to replace it, but I was just trying to account for the possibility.

I found some pics on benzworld https://www.benzworld.org/threads/4m...s-r-r.1579512/ . I would post them but for some reason, it's not working.

They make the picture much more clear. If I have to press out the bearing, I can get that done at a shop. Thanks for the heads up.

The only cleaning you would able to do is behind the knuckle. The speed sensor inserts into the knuckle at the back which gets its signal from the magnetic ring on the back of the bearing. Removing the bearing requires replacement with a new one because it's destroyed on removal and there's no getting around that.