I have a chance to get a turbo off another 300SDL as I am afraid mine is slowly but surely failing. I have to check if it's a KKK or Garett first, but how can I check besides the shaft play, the turbo's health.

I crawled underneath my car again yesterday and there is a good amount of oil on the underside of my turbo, and I don't think it's leaking from anywhere above it, is this a hint? The car does not leak alot of oil.

Also, how difficult is it to R&R a turbo in this car. It looked pretty straightfoward to me, only thing I am really concerned with is those bolts that got red hot and cooled a million times.