The clamper arm can be adjusted to raise it back to being parallel to the top plate.  You can check the service manual or search the forum for the topic, there are a few threads on this.  It requires removing the glass lid and the top plate for the clamper arm.  Then you can access the adjustment screws.

My 9000 did the same thing, it was the what they call the "rocker arm" that was worn. There is rubber washer over part of it that wears away with age. I changed it the arm and no more scraping.

I believe you are describing one of two issues. Can you clarify?

Is the scaping happening when the CD is spinning? Or is the scraping happening when the sledge is moving to another CD?

Either way, please verify that the placement screws are set correctly. See page 4-7 of the owners manual (found online).

The placement screws are Set correct. The scratching noise emitts when the CD is Spinning, sliding of the head ist absolutely noiseless.

Could you please Tell me which screws, number in th Servicemanual, have to be adjusted.

Does this sound like your issue?

There are 2 distinctly different problems with different solutions.

#1 - as you describe, the clamper arm contacts the disc.  On page 4.5 of the service manual (Sledge) you see 2 screws #34.  These adjust the clamper arm.

#2 - the sledge strikes the discs (from below) as it moves from one disc to another.  The rocker arm or rocker arm damper can be replaced to cure this, or the 2 small springs that are part of Module 9122 that attach to Modules 9137/9138 need to be replaced.  These 2 small springs are what moves the sledge when you center the CD Mechanism (using the two placement screws mentioned above).

It seemed like you were describing issue #1 above, if so adjusting the set screws to get the clamper arm setup correctly seems right.  This is described on page 5.2 of the service manual (for MK3).

The rocker arm repair is described somewhere on the forum with photos if I recall.

that's what it sounds like to me, seems to be the same

sound of scratching

It does sound the same. Try the methods mentioned by Bill. In my case I had to replace the whole clamper arm (2854207) as it had physically broken due to heat and I couldn't bend it back into shape. Old on left, new on right. Login to view image