Mercedes Benz repair: 1976 300d passing gear, bowden cable, vacuum pump

Question
I have a 1976 300d that has a problem with passing gear. It shifts to 3d gear too early and does not shift down when floored. I do hear the switch click. Occasionaly it will downshift for a couple of seconds. Transmission seems to be tight and upshifts well. There must be a linkage adjustment somewhere but I couldn't decipher it. Can anyone help? Thanks, Chuck in NH

Answer
Answer:
Possible Bowden cable issue and/or vacuum loss.

Transmission:
http://www.mercedesshop.com/shopforum/showthread.php?t=142395


Rebuilding the Vacuum Pump on the 617 Engine
[url]http://207.210.95.34/~boostd/easley/Rebuild_vac_pump.htm[/url]

1982-240D-Vacuum System
[url]http://www.mercedesshop.com/shopforum/showthread.php?t=105201[/url]

Vacuum pump lesson learned
[url]http://www.mercedesshop.com/shopforum/showthread.php?p=872760[/url]

Vacuum Pump Gasket Sealer & Torque
[url]http://www.mercedesshop.com/shopforum/showthread.php?t=138153[/url]