Is this a vac operated shifting mechanism??? I am experiencing some inconsistent shifts on the car. At low speed from 1-2 it shifts smoothly but when accelerating harder it is noticeably sharper and not quite what I think it should be. In higher gears its shifts very smoothly. Any adjustment than can be made? Possible service issues?

Regarding my other post, the trans fluid is at the proper level.

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1981 300TD
2005 C55
2004 E500
1999 ML430
1992 400E
1998 C43
2001 SL500
1988 300SEL
1986 190E 16V
1991 190E 2.6