Transmission won't shift into Drive

[Benny Berry]

1985 300SD local drive, floorboarded into passing gear fine, but didn't ever yet shift back to drive. Drove the 5 miles home. Starting from routine stop it shifts I think its twice but will not go to regular drive speed gear. This has happen a couple time in the past two years but those times I did a quick accelerator to floor and release and it would shift out of passing gear and back into drive as normal. Lubed some linkage then it didn't fail. Now that action doesn't make any difference. Today looked at linkage and wiggled them and vacuum lines no real action taken, then went for ride and it was not shiftingup as should, had to do strong acceleration and let up to get shift ...but no way to make it go to normal drive speed. At 50 mph its doing about 3000 rpm which it sould be doing 70 at that rpm. Any thought appreciated. Thanks Benny