I drive a c180 estate 2001, recently when I investigating the 'common' front suspension clunks noises I find the top of left and right strut mounts/shock mounts are loosely attach to the car body under the bonnet. the problem is identical as this video described. Any ideas are they related to the clunks noises and do i need to tightening something to reduce the gap. Many thanks for any opinions.

add something:

When release the jack and the car stand on it's own wheels there is a 10 mm gap between the the small black metal bracket and the rubber on the car body.

My next door neighbor says this gap is normal , !!!! SHOCKING !!!

I believe your neighbor is right.

I don't know about 10mm gap ... maybe it should be closer to 5mm.

That top bracket SHOULD NOT be touching the car.

That top bracket is just a catch plate so when you jack up the car the strut assembly won't fall out. The top of the strut assembly has a big rubber mount that looks like a small upside-down bundt cake ... it fits in a pocket in the underside of the fender well to hold up the car. The top of the strut shaft goes through this rubber mount, which has a metal sleeve in it. The nut on top tightens the shaft to that metal sleeve. The nut should be about 40 ft-lbs. There is also an inner lock ring on the shaft below the nut and catch plate, that actually fits inside the metal sleeve. That needs to be down below the top of the metal sleeve to allow the top nut to hold the shaft securely against the metal sleeve. If it is not below the top of the metal sleeve, then your top lock nut will be tightening the catch plate to the lock ring and not tightening the shaft to the metal sleeve. If there is any play in the shaft where it is mounted onto that sleeve, it can potentially make noise.

The rubber mount itself can bend and stretch a bit, since the geometry of the front suspension (i.e. the strut shaft orientation) changes a bit during travel and turns. I haven't stared at mine while the car is driving, so I can't say for sure if yours looks like it's moving around too much.

However, when these mounts break down they basically tear around that inner shaft area. One way to check this is to jack up the car again, let the strut hang on that catch plate, then shine a flashlight in there to see if you can spot any cracks in the rubber opening up. You should be able to notice them pretty readily. If there are cracks, it's time to change the mount.

Refer to this thread for more info on the strut mounts:

https://mbworld.org/forums/c-class-w...placement.html

thanks a lot guys, now i am not worrying about the gaps anymore. very professional answer from jkowtko.

This was a good read.. Just did front overhaul to my suspension and noticed a small little gap between the bracket and the rubber mounting before the strut not even close de 5mm but theres a gap.. When I lowered the car I noticed it appear (the little gap)..

That is definitely an indication of worn strut mounts (the big, rubber piece). The clunking, along with that much movement is a tell-tale sign.

The strut bearing, strut /shock and spring are al new, i've gotten input from various claiming this is normal.. IDK

I just listened to the video again. If it's a loud clattering/knocking noise, in my experience that was due to the shaft not being fastened tightly against the top mount. We had this in our Toyota Sienna -- huge clatter -- and simply tightening the top nut properly eliminated the noise completely.

But remember, on our cars there is an inner lock ring that sits under that bracket. That ring needs to be screwed down below the top surface of the collar of the mount or your strut shaft will not be held tightly. That lock ring is part #910113014001, #17 in this diagram:



I hope this is clear. The ring has two notches on opposite sides. There is a special tool you can buy for ~$15 to work it, or you can just use a couple of flat screwdrivers to push it around, since it isn't supposed to carry the load of the shaft (the larger top nut #20 carries the load). Just screw it down enough so that it doesn't interfere with your tightening hte larger top nut tightly against the top of the mount collar.

Other than a loose strut shaft, the sway bar link is about the only other thing I can think of that would make that type of noise.

-- John

Sorry for digging that old thread from the grave, but what could be the reason if that top bracket is touching the car and how it would affect the steering?
I just bought a W203 for everyday car and I am investigating some issues with hard steering.
I have replaced the power steering fluid with no effect and I was going the replace the hydraulic pump, but I just saw that on the right side strut that bracket not only does not have a gap, but fully lies on the car.

The other one has a gap around 5mm. So I searched for some info and got here

Hi DDilian,

The only reason I could see that top bracket tightened against the car is that the rubber "bundt" isn't seated properly.
Note in the pic the larger opposing ribs ... there are corresponding depressions in the well where the mount sits to match up with these. If the mount is turned it may not sit in the well fully and will be down more than it should. Compare the relative height of the top of the bundt against the car body between the two sides on your car.



So how to check for and fix this?

1) With car on ground remove the top bolt and bracket ... nothing should go anywhere at this point.
2) Slowly jack up the car and watch as the top of the shaft and bundt start to drop out of the well. As the assembly lowers you get a better view of the top of the bundt and how it is oriented.
3) Once you've got a good (inch?) gap in there, the bundt should be free enough that you can turn if it needed to seat it properly. The top rubber part sits on a ring bearing and turns independently of the spring seat.

I've never turned the bundt in this manner, but it should be doable. If it's too tight to turn by hand, then use the steering wheel to turn the entire strut assembly when the car is raised to rotate the bundt, then lower the car to reseat the bundt. If the bundt needs to turn more, then center your steering, raise the car again, rotate steering to turn bundt, lower car to seat bundt, turn steering back, and repeat this process until the bundt is oriented where you need it. Again I've never done this, it just seems like the only way to do it short of completely removing the strut assembly.

-- John

Thanks for the fast reply. I will try that as soon as possible.

Also note that the bundt shaft is angled (rearward I think as it sits in the car), it is not perfectly perpendicular to the base that it sits on. If by chance it is rotated 180 degrees from where it should be you would have a really screwy setting of this strut mount, with an incredibly uneven load on the ring bearing between the top and bottom pieces.

Let us know what you find out. Take as many pics as you can.

Thanks. John