W202 250TD Autobox

[The Old Man]

1997 C250TD. 129k miles. Box sometimes "surges" on change-up - i.e. the box is slow to change up, the revs momentarily rise, then the higher gear selects with a clunk. Additionally, on moderate acceleration, the box will change up, then suddenly change down again, with the revs going sky high.

Any suggestions?

 

[Hibbo]

Check the Bowden cable (AKA Kickdown cable or Pressure control cable) is correctly adjusted where it meets the throttle linkages. (If you disconnect it, it should *just* go tight when you reconnect it).

Is the oil level correct in the box?

When was the fluid and filter last changed?

 

[eric242340]

1997 C250TD. 129k miles. Box sometimes "surges" on change-up - i.e. the box is slow to change up, the revs momentarily rise, then the higher gear selects with a clunk. Additionally, on moderate acceleration, the box will change up, then suddenly change down again, with the revs going sky high.

Any suggestions?

Could you give more info here, ie the service history would be one point. Sorry im a blunt Yorkshireman. There are so many questions here. On what you have posted thus far its hard to give a sensible answer. please give more info

 

[The Old Man]

Na then Eric

The car's new to me. It would seem it's not been regularly serviced, since the service book is woefully short of entries, but paradoxically the general condition of the car indicates it's well-maintained.

The changing down typically occurs when, for example, joining a motorway. Off the roundabout, down the slip road, accelerating in the same gear, not to the point of kick down. Acceleration is good, the box changes up, then immediately changes down again, with, of course, your foot still on the loud pedal. Gentler acceleration avoids the problem.

The other fault - pause then clunk, is intermittent and can occur when the car's hot or cold.

 

[Hibbo]

Change the ATF and filter.

This is for a different car but the procedure is exactly the same. http://www.forums.mercedesclub.org.uk/showthread.php?t=25566

 

[television]

Change the ATF and filter.

This is for a different car but the procedure is exactly the same. http://www.forums.mercedesclub.org.uk/showthread.php?t=25566

As hibbo really,there is nothing else that you can yourself, there is a good chance that it will make it better, if it does not then a gearbox specialist is the only answer. It does sound a little torque converter related, and this could be affected by the fluid.

Let us know how it goes when you have changed,or had the fluid changed.

Malcolm