Mine is plastic at both ends. I cleaned it & used silicone grease to lube it but the plastic ends still grab the ball a little too tightly ( until the engine warms up). As others have commented this will sometimes cause the rpms to be excessive.
What have any of you'll done to minimize or prevent this?
I have ordered a new linkage rod that has to be shipped in from Germany ( about $35 ). Part # is: 0 001-070-85-75 rod throttle through Plano Dallas Mercedes
Is there a linkage kit available so different length rods can be made? I've searched the internet without success.
I'm in the middle of about a 3-4 week work effort to:
1. replace glow plug wiring harness
2. replace delivery valve o-rings & copper washers
3. clean intake manifold
4. replumb engine vapors & oil to a catch can instead of intake manifold
5. replace alternator pulley with gates 37011p ( might need 96 alternator, don't know yet )
6. replace front flex disc
7. replace shifter lower plastic bushings
8. replace motor mounts
9. pull monowiper assembly to clean & lube
10. pull blower motor to clean & maybe replace brushes
11. replace belt shock reducer
12. try to figure out why both front windows don't move
13. try to wire in a bluetooth adapter so I can play music from my phone
So far everything has been easy

, just takes the time & lots of searching to get guidance on how to do the work. I think my car was built about May of 95 so some older car pictures are close but not the same.
I've taken a few pictures & will take more if any of you have an interest in what things look like. PM me is ok.