By the way I am the mechanic... This is just one remedy I found that someone else posted on another forum. Sorry I just copy and pasted here.


Im new to this website but not new to working on cars. vettdvr makes good points, you have to learn by doing and be safe at the same time. I also attempted to replace the bearings on the front hubs. Dealer was only showing the entire hubs as replacement, I tried to take another route and just get the bearing numbers off of the old bearings and install the replacement bearings with a new oil seal, (tone ring to mercedes) more on that in a minute. after unsuccesful attempts to get the ABS, ESP warnings off of the dash after installing the hubs with replacement bearings, I finally researched the bearings more. I only found the bearings that orinially came out of the hubs available from china.. the national bearing replacements were not an EXACT micro match of the old bearings, these newere bearings caused a difference in diameter or distance from the sensor in the knuckle which thru off the computer, hence my ABS, and ESP lights went off. I highly suggest that you buy the OEM mercedes hubs, they come fully assembled and ready to install with grease. just get your torque right on the spindle nut and you should be ready. Now the tone ring.... they call it the tone ring because it is a metal ring surrounded by rubber. this oil seal ring is installed same way as grease seal and it is used by the sensor to calculate your speed, ABS and ESP. so in short, I spent $80bucks on replacement bearings and then had to spend the cost of the new hubs on top of that. all is well now...