Just bought a 82 300 TD w/ 177k on it. When shifting into "D" or "R" there is a momentary delay before engaging and an audible "thunk". Not grinding, just engaging. Noted in maintainace records that previous owner had taken car into mechanic and mechanic noted on bill "client states that transmission not functioning correctly. Adjusted modulator".

Please advise. Thank you!

The modulator has NOTHING to do with initial engagement of the trans. Have you ever been in a simular car as yours to check the trans engage?

I have an 84 300TD w/165K and have developed this same problem. For me it happens when shifting from Park to Drive or Reverse. I had a leak in the transmission cooler line on the driver's side. After replacing this it's a little smoother, but still not the way it used to be. Any ideas?

my 84 300d turbo with 118,000 does that too. i just learn to live with it.

pkmorgan17,
I know this posting was from a while back, but did you ever fix that 'thunk'?

Just curious, because the note, "...adjusted Modulator" caught my eye.

I just recently "adjusted the modulator" on my '81 300TD-T to make my shifts a little more hard. It is very simple, and easy to find.

On the driver's side, just above the AFT pan, there is a 1/2 dollar sized (green on my car) modulator. Pop off the sm

There you will find a very small "T" shaped key. Turn the key 1/4 turn clockwise for harder shifts, 1/4 turn for softer shifts. This has nothing to do with the shift timing, only the softness/hardness.