Noise when pressing the clutch, new throw out bearing
 

Howdy everyone, long time no post.
I've been working anything and everything except my Mercedes in the last year or so. Being busy the last maintenance I needed was the clutch, and I had Derek (TurboBenz) while he was working at one of the local independent shops. Well, when they did it, there was a problem getting the correct throw out bearing, so I gave them the OK to reuse the old one. Now, about 2000 mile later its making a noise when you step on the clutch. So, ok time to do the throw-out bearing. Derek, who moved out of the area, was cool enough to come to my house and change the bearing for me. That was Saturday. We got the transmission back in and step on the clutch and the noise is still there!!! So them my weekend changed from me working on a welding project and Derek working to the car to Derek and I in full investigation mode. We pulled the transmission again and the pilot bearing fell out of its bore in the crank. so we got a new pilot bearing and used a little loc-tite to keep it from falling out. put it back together... SAME NOISE. So its nether of the bearings. That was Sunday. Today after work we worked on it again. took everything apart and started inspecting every part in the clutch system. everything looks new, as it should. We then looked at the transmission. The clutch "fork" looked warn where the throw-out bearing rides, and when you shake the clutch fork it sounds like the noise we heard. After some internet searches we decided the fork must be the problem. I took the fork and welded new contact pads for the bearing. ground and filed them til they looked just like a new fork. Installed everything and its still making the noise!!!!

Here are some pictures of the clutch parts.

http://i131.photobucket.com/albums/p...B5ABAAB822.jpg

http://i131.photobucket.com/albums/p...7905207397.jpg

http://i131.photobucket.com/albums/p...C99FAC8F82.jpg

http://i131.photobucket.com/albums/p...5FD3C85CA2.jpg

http://i131.photobucket.com/albums/p...B4BB881364.jpg

Here is a video we made of the noise, take a listen. We need some "second" opinions!!

https://www.youtube.com/watch?v=CcVfbtQ3-I4

Here is a question we should know the answer to... Does the raised side of the clutch disc, the side thats up in my picture, does that face the flywheel or the pressure plate? we have it installed the same way we took it out with the raised side toward the pressure plate.

You had the Disk mounted correctly, Raised part towards the PP.

What is up with the spring at 5 o`clock position? looks flat and worn.

There is two different throw out bearings. One for the early Iron Box trans,
and one for the later all one piece aluminum box.

I know they use to be listed as up to xxxx cassis number for one, and then
the next listed chassis # after that for the later one.


How is the "MOM" Car? Still putting right along? Haven`t seen you in a while.
Probably since you gave your Mom the car at the GTG.


Charlie

Is there a large spring missing from the 10 o'clock position?

Large spring in 4 o'clock position is broken and missing a piece?

Uneven pressure from a missing large spring in the 10 o'clock position, and a broken spring in the 4 o'clock position could account for the noise.

Are there wood wedges in the four oclock spring?

Charlie! Glad you chimed in. The mom car is running great. Mom moved back to CA so I get to see her and the car more often.

I'm preplexed because Derek and I both looked at the clutch disc and pressure plate up close, like nose in the thing and I can't see any witness markes of where it is rubbing. makes me think maybe its something chattering. The idea of uneven pressure on the pressure plate was one of my ideas. Why I reshaped the clutch fork. It didn't even make the sound change :(

I might be able to get my hands on a used pressure plate and clutch (junk yard) I guess I could install them and if the sound goes away we know its one of those parts. I feel like I'm just throwing parts at the problem at this point.

All springs seem to be in the correct places.
Here is the catalog image of the clutch.
http://i131.photobucket.com/albums/p...1861792235.jpg

That is what I mentioned but think you are right something between the coils.

There is 3 different size springs on the Sachs Disk. 12 and 6 being the largest.
I had a Sachs disk break those 2 springs and crack the center metal part on
my 85 300D conversion.

Some other clutch manufactures (maybe LUK) only have 4 springs.


Charlie

the 4 oclock spring is one of the small springs. as you can see in the catalog image. what your are seeing is the ground. I took the picture with the clutch sitting on a brick wall.

I read some reviews on the Sachs clutch here on the parts store page, and seems they are not all they're cracked up to be... or maybe they are... cracked up that is. :(

But we poked all the springs with a screw drive and not of them seemed to be cracked or loose or anything like that. Sadly the local parts house who has a clutch in stock that I could install tonight only stocks a Sachs clutch. And with this one not showing any signs of damage I wonder if a new one would be worth it.

The paint on the yellow springs seem to be scraped, I don't see how this could be unless the pressure plate spring is contacting them some how.

You've checked the flywheel bolts?

You didn't show the finger side of the pp so we cannot tell anything about how that is worn. uneven wear on them can cause dragging of the clutch.

How much play is on the transmission input shaft?

There is slight play in the input shaft. but no sound is made when its in gear and power going into the input shaft. only sound when the clutch is pressed. I spun the input shaft by hand and its quiet.

I just talked with Garrett, and hes going to come by with a used clutch disc and pressure plate, and we're going to change them out one and a time and see if it changes the sound at all. I have this gut feeling its coming from the clutch disc, but who knows.

Right now all the parts are back in the car. I'll take better pictures when we pull it apart again.

Yep flywheel bolts are tight.

New Theory.

There is slop between the throw out bearing and the sleeve for the input shaft. If the throw out bearing engaged the pressure plate slightly off, maybe the bearing is oscillating and causing the fork to rattle? the sound is a metal jingle sound.

Just a thought I just had.