strut mount vs strut bearing




I have a question on clarification of the strut "mount" vs "bearing". The two terms appear to be used interchangeably, however the Corteco mounts I just purchased do not appear to be able to fit together and allow turning without a donut-shaped bearing in between them. I've never seen this bearing sold separately (I think some mounts you can purchase may already have it already installed), nor have I even seen a pic of it. Pics of my strut mounts are below.
Question -- does anyone have a pic or specific information on the bearing that fits between these two pieces? I would expect to just pull out and reuse the existing one that is on the car, but I don't want to be in for a surprise when I take my front suspension apart.
Thanks. John

Thanks for the offer but I'll probably go with new parts.




98K and the struts are just feeling tired. I can tell most when backing out of a driveway or going slowly over a speed bump ... the damping just isn't there and I get some squeaking as well.
I can also see cracks in the top of the strut mounts, when I jack up the front end and look down through the bump stops in the engine compartment.
I think the springs are still fine. Ride height is good.
Fyi, I replaced the rear shocks with Bilstein TCs about a month ago, and what a huge difference! Travel over small bumps is smooth and quick, entering corners feels flatter, and suspension lands firm on large drops at higher speeds. For Bilstein's softest shock they are a noticable step up from the originals.
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* 2 Bilstein TC struts ~$95 ea
* 2 strut mount kits (bolts/washers) ~$25 ea.
* 2 strut mounts ~$45 ea
* 2 upper control arms (torque struts) ~105 ea
(these are the Lemfoerders with the non-adjustable bushings .. another thread)
* 2 sway bar links ~$35 ea (make sure you order the ones for the sport suspension ... they are different from non-sport)
I haven't purchased the lower control arms yet but will probably do that soon. The uppers should be replaced when you do the struts, because you have to unbolt the strut from the steering knuckle in order to get the upper control arm ball joint out. The lowers can be replaced independent of the rest of the work.
I also have not purchased the sway bar bushings yet because I can't find them in my size. I have the 2005 C230 which evidently has a C55 sway bar (22mm) and not the stock 20mm or 21mm sway bar. Bushings not available on EPC-net. These can be replaced later as well.
I am also hoping to hear an answer about the strut bearing before I start this ... I am assuming that I should reuse the existing one, but I'm a little concerned about the lack of on-line info about this including lack of detail in the EPC-net and parts.com diagrams.
My car's at 98k, and I don't have an issue with my springs. If your ride height is still correct then I would not expect springs to be a problem. If the spring were to lose it's tension, you would notice the car height dropped when at rest, and when someone sits in the car. If the car just feels like it moves too much over bumps and depressions in the road, it's probably just the shocks/struts. I would suggest you try replacing the rear shocks first ... other than removing the trunk liner, they are pretty easy to replace, independent of rear spring replacement, and you should notice a big difference right away. I did mine about a month ago and it's made a big difference in ride quality. The car doesn't dip anywhere near as much on road depressions as before.
Last edited by jkowtko; Aug 13, 2012 at 05:45 PM.
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This isn't my top priority but I do plan to do this in the next 8 months. At 143k my suspension is feeling old, too, even with all new bushings.




* 2 Bilstein TC shock absorbers ~$85 ea.
The rear suspension is a standard shock/spring suspension, the shock is held on by a bottom bolt and a top nut (straight shaft top), and the Bilsteins came with their own hardware and rubber bushings for the mounts.
From reading other threads on the forum, people feel that the rear suspension parts are pretty robust and generally don't need replacement. With the new shocks in place the rear end on my car feels pretty snug.





The white ring on the bottom left picture is the actual bearing. It's a thin ring about 1/2" wide and 3/8" thick that fits into the bottom of the rubber mount, allowing the mount to turn on the spring seat (the larger part) while supporting the entire load of the front suspension.
Last edited by jkowtko; Aug 26, 2012 at 12:14 PM.




But as a measure of safety if I were to do this again I would probably look for a strut mount that includes the bearing, just so I don't have to deal with the issue of discovering a bad bearing once the strut is out of the car, and then having to go out and purchase a whole new strut mount that includes the bearing -- which I would probably end up getting from the dealership for an outrageous price..
It is concerning that you can't get the bearing anywhere as a separate part, yet some strut mounts are sold without it.
I just ordered a new strut and mount. I do not have the torque specs for this job. Does anyone have them on hand it would be really helpful. I am not sure where to go to find them.
Thank you
T




Could one of you kind people brainstorm a bit on this with me. I am still having an issues after changing the front struts and mounts.
-Noise when turning sounded like strut mount bearing but I guess it was not.
-Also when breaking I am getting a woobble feeling/sound in the steering over small bumps. I assume and it was suggested by a mechanic it was my front struts/shocks but it was not the car is the same.
So, any brilliant suggestion only other ideas?
-Could it be the sway bar? or some kinda bushings in the suspension.
-Also just something as simple as Alignment ? I plan on aligning the front tomorrow.
Thanks in advance.
Cheers
T
Noise might be the ball joint(s)? Control arm ball joints or a steering tie rod ball joint.
https://mbworld.org/forums/c-class-w...solutions.html
I have the opposite problem to yours
Have a clunk over bumps on the left side. Replaced sway bar endlinks, did not help. Now it seems it's the strut mount.
Last edited by VVF; Feb 25, 2014 at 04:12 AM.




Also please confirm if you replaced upper control arms or not when you did the struts.
As far as front suspension movement when braking and going over bumps, I would suspect the control arm bushings first, then move on to the steering rack and tie rod ends. The sway bar links make a lot of noise when bad but I don't think they affect steering feel when braking.
I replaced my upper control arms when I replaced the struts, and there was still a bit of knocking noise when braking. Then I replaced the lower control arms and the noise went away. So if the struts needed replacing, chances are that the control arm bushings are tired.
Also, now that I've replaced everything but the rack and tie rods, there is still a bit of looseness and ever-so-slight clunk, which I suspect is either the rack bushings, inner tie rods, or a problem with the pinion assembly in the rack (which would require a new rack). My car still pulls a bit when braking.
As for wheel alignment, toe-in is about the only thing you can adjust, I did my own and my toe-in is about zero right now, probably could be pulled in a bit. But my steering feels clean and straight right now so I hesitate to adjust it again until I deal with the rack issue.
And before you waste your money on an alignment, do your own toe-in check to see if it's out of whack or not. Use a tape measure to find the spacing between two reference points on the tire treads, compare front to rear spacing. Because the underside of the car gets in the way you'll only be sble to measure a point 1/3 up the tread on either the front or back side of the tires. But these two points should still be 18-20" apart from each other giving you good geometry for angle calculation. My rule of thumb is that the rear spacing should be 1/16-1/8" more than the front spacing. If it's outside of that range you can actually adjust the toe-in yourself. Do a few iterations and drive the car after each adjustment to see how it feels. Paying $90 to have someone do this is a bit much for me.
Last edited by jkowtko; Feb 25, 2014 at 10:34 AM.
It seems you were both right. Before I went and forked over the money for an alignment I took another look at the items you mentioned and ended up replacing the front left lower control arm with bushing and ball joint ($134). As well as the left inner tire rode($53). The sound is now gone . Thank you for the brilliant ideas, just wish I did not go an buy new struts and mounts first.
I bought the inner tie rod from the stealer as it was only 10$ more than aftermarket . The lower control arm I picked up aftermarket it was half the price but the car feels much much safer now.
Thanks Again




I wouldn't worry about new struts and mounts ... there's a good change they were on their way out anyway.
You might consider replacing the other lower control arm though, to keep the repairs symmetrical. Especially if you are doing DIY, it's worth the parts cost to refresh a nine year old suspension.



