fast/hard shifting, 190DT

[babymog]

Took the tour, did the search, can't find the answer.

It looks like my transmission ('87 190D Turbo) has a mechanical kick-down, moves freely, what else can cause the car to shift hard and at low RPM?

Thanks

- Jeff (Noob)

[Brooksie43]

Hi Jeff,
It may be somthing very simple (or not). Make sure you have not knocked off a vacuum line of the several that run from the injection pump up to the 2 valves on the fender well. Maybe while changing oil. These lines (in part) are what control the cold shifting. They do the same thing as a vacuum modulator on a gasoline vehicle, that is, more pressure is applied to the clutch packs in the transmission as more power is produced by the engine. Otherwise you would have hard shifts at low power aand/or slipping at high power.
Since your diesel vacuum does not vary with the throttle position, and since these transmissions shift hard when cold, there are valves to vary the vacuum and these easly damaged lines and rubber "Y" fittings (in part) control that variation. I have the same vehicle as you, best car /engine combo ever.
Start there

[babymog]

Thanks for giving me a starting point, I'm doing a lot of sorting out this week, will look over the 500 vacuum lines tonight ;~)

- Jeff

[babymog]

I went through all of the vacuum lines, all soundly connected. Still in 4th gear by 35mph at full throttle, ... something's amiss. Possibly not connected correctly?

Where should I check vacuum (w/gauge) and how much vacuum should I see? Preferrably in the transmission control circuitry. My HVAC seems to have adequate vacuum for proper operation of flaps/valves, as does the brake booster. I will spray a little starting fluid around the lines to see if I can find a leak that way, but I'm not convinced I have a leak at this point.

Any other suggestions?

BTW I agree that the 2.5DT in the 201 is a nice combination, although I miss my TE 4matic's space and ortopedic seat.

- Jeff

[ytr1903]

Babymog,

You may take a look at the adjustment of the Bowden Cable on the valve cover. These two threads say it a lot better than I could.

Bowden cable, is this the adjustment

Bowden cable...

Tom

[jaoneill]

I had the very same problem with the 190D 2.2 when I bought it. I couldn't find the problem and finally, after six months of hard shifting, I relented and took it to a dealer. Eight hours and $600 later they informed me that they had found two vacuum lines that had been switched / reversed. Vac is vac, so I don't understand how that was possible but it has been smooth as silk ever since.

Good luck,
Jim