Bottoming Out/Tire Rub
 

I am having an issue with wheel rub when going over dips in on the highway at normal to high speeds. Sometimes it squats low enough to flash the display red (too brief to read it). Sometimes it's pretty bad and sounds like metal scraping. I'm not really seeing any indicators of rubbing but something is somewhere. I have 20" wheels on it. Not sure of the offset. These wheels were on the car when I bought it. The rodeo test was performed on the vehicle and no errors. I know the front struts need to be replaced soon but this happens front and rear.

i have 20x10 rears with a 285/35s. i rub under heavy compression but nothing serious.....you getting the red would worry me. not sure how low you drive; you could be tripping the abc sensor

I usually drive on the lowest setting unless I'm on a 2 lane country road with lots of dips. I find that even when I drive on the highest setting on those roads I still rub a bit.

Momentary red abc warnings on bumps indicates the 4 air cells/accumulators are due for replacement

Where are they located? Is that a difficult job?

Just finished replacing mine. One is in front of the drivers side front tire. You simply remove the plastic wheelwell liner to get to it.

Another identical one is located on the passenger side behind the rear axle above the exhaust. You need to remove that muffler to replace that one. Muffler removal is sImply a band clamp ahead of the axle, one bolt/nut connecting the two pipes, and slips out of the rubber hangers.

There is another by the fuel pump. Remove the plastic cover from the bottom of the car on the drivers side just ahead of the rear axle.

The last one is under the car about where your passengers feet sit. Remove the big plastic cover under that section of the car and it is easy to do, you just need a thin 24mm wrench for that one.

Like tunabes said, you need to replace all four accumulators. I did it myself a couple weeks ago, pretty easy job. It will get rid of that red error flash.

Will it stop my tires from rubbing?

Im not too sure if it will solve the rubbing but you have to keep in mind that you are running 20s and Im not too sure what the profile of your tire is so that can be the case. Im running on 2013 oem Cls550 wheels and tires and they rub when ever I hit a bump but thats because I'm lowered.

The tires are very low profile. I'm not running lowered. Had I been I would expect a little rub but I'm running factory height and getting a LOT of rub.

The offset of your wheels is wrong. Pull them off and take a look at the info stamped on the back. Stock rears are 19x9.5 with a 60mm offset (on a CL65, not sure on your 55). No reason you cant run 20's with the right offset, but if you are rubbing I bet it is because they stick out too far.

Short of buying new wheels, would it be advantageous to roll the fenders? It rubs front and rear. All I know right this minute is that the tires are 255 front and 285 rear.

If they are rubbing that bad you are not likely to gain enough clearance by rolling the fenders. Until you remove one you really have no idea what the issue is. For all you know, the previous owner liked the wide offset look and they rub because there are spacers behind them. Pull a wheel from the front & rear and find out what you have. Also, take pics of them on the car and post them up, maybe we can see if they are sticking out too far from some pics.

Rolling the rear might help a little but for the front, you would have to get them shaved since the fenders are plastic. The thing with shaving the front fenders, they become weak.

There's your problem, those tires are fat. The rim isn't sticking out too bad but it's those tires. You have to run a smaller tire to fit those rims, almost looks like a truck wheel haha.

The reason I assumed suspension is because there is a LOT of up/down travel. Reminiscent of a blown strut on a typical suspension. If that's normal then tires it is!

Thanks for all the input guys!

Hate to say it but I disagree JPhamily. 285's are not too wide, it's the wheel offset. I plan on running 295's on the rear with my 10" wide wheels when my current rubber wears out. There is plenty of room in the wheel well as long as the rims have the right offset. Those rims just stick out too far. I bet he has 2" of room on the inside of the wheel.

Heck there are a few guys running 305's.

The wheels that came on my car rubbed too and they were 19x9.5's with a 38mm offset running 275 wide tires. I know the 65 takes a different offsert than the other cars, but those wheels are wrong for that car.

What size are the front tires that are also rubbing?

255s in the front. I don't know what the offset is.

Here is a great wheel offset calculator for you to determine how different wheels will fit. Just entyer the dimensions of your stock wheels, then your options and see how things will line up.

http://www.jdmconcept.com.au/wheel-offset-calculator

I think you need a 30 series tire at the back and 35 at the front for 20" rims.

Look here to see what will fit http://www.alloywheelsdirect.net/inf.../mercedes-benz go to the w215 section

And your offset is all wrong!

Will I need to buy new wheels then to solve this or is there another way to alter the offset? If I do need new wheels, know anyone that wants these? lol

You can push the wheel out using different offsets however you need to bring them in a little so nothing can be done. The best thing you can do is roll the fenders or get a tire that is not as wide. My advice would be sell the wheels keep the tires if they are good and buy some new wheels with the correct offsets.

They will probably fit a C or E class better with that offset. I would reccommend finding out what the offset is as a buyer will need to know that to see if they fit their car....