Yesterday my 85 300 TD automatic stopped "kicking" down at its normal speed/rpm settings. For the last several years its been doing so very reliably always dropping down 1grand after acelearation from stiop or on the highway, from 4000 rpm to 3000 rpm at about 60 mph and 10 mph.
Now it waits another 10 mph before it wants to kick down. the egine literally screams before it drops down to 3 grand--I have to be doing 80 mph on the highway or 15 mph local.
I know thers an adjustment on top of the valve cover at the kickdown cable. I've adjusted it before. However before I do so I would like to know wahts caused this erratic behaviour.
85 300D Turbo -- I lost my kickdown

Check the switch under the accelerator. It may have gotten debris or dirt lodged in there. That would stop it from working.