I just purchased my 83 SD this week and it only has 131K. When stepping on the accelerator it takes a few seconds before she actually starts to move. My N/A 300TD takes off quicker to 20 mph. After 20 though this thing gets going.
It also seems to shift very soon into fourth gear. If I decide to manually shift her on hard throttle she shifts into 2nd well (chirps tires), when I shift her into 3rd she will just rev till I let off the accelerator a little and then bangs into gear. When I shift into 4th (D) its hit or miss when she wants to engage. When I floor it regularly sometimes it shifts into 1st in 2 seconds and sometimes not till around 40mph. The 3/4 shift is almost always within a second of each other. When shifting from drive to park it still sound like something is moving or slowing down internally before it park engages. 1-2 seconds.

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2022 Nissan Frontier Pro4x
1990 Mercedes 420SEL
1950 Packard 8

Previous German cars-
2001 Mercedes SL500
1983 Mercedes 300SD
2011 BMW 328i (manual)
2008 BMW 535xi (manual)
2006 BMW M3 (manual)
1980 Mercedes 300TD
2006 BMW 750i
1996 Mercedes E300D
1994 BMW 740i
2006 BMW 330xi (manual)
1999 E300DT Smoke silver/black 253k
2012 BMW 535i Xdrive M-Sport
1984 300TD-T 304k
1988 Mercedes 560SEL (parts car)
2010 BMW 550i xdrive
2017 Audi A4 Presitge
1979 300SD 313k
2003 E500 189k