E420 Starter Noise?

[emerydc8]

There is a noise that occurs on engine start, immediately after releasing the key. I originally thought it was a loose timing chain, but I have checked that out and replaced the timing chain tensioner and upper guides. The upper guides were perfect, other than being brittle and breaking when I replaced them.

Now, I'm thinking it is more starter-related. Over the past year or so, occasionally when I would engage the starter, I would hear a whining noise followed by a short metallic grinding noise, like the Bendix came out but did not completely engage and turn the flywheel. I could retry it and it would start okay the second time. That only happened about once every few weeks.

Within the past month, I am now hearing a noise that sounds just like the noise this Bendix is making after it retracts away from the flywheel.

starter - YouTube

Is the Bendix a common failure point for these Bosch starters? Anyone else experience this?