I have a 1984 e 150 and it runs slugish and acts like it does not want to shift. It ran fine on the way to work.

Go and run a scan on it,it is possible you problem with any of the shift solenoid in the transmission,then check if the abs light is on,try to resolve that one also.

Change the fuel filter.

Hey RPG, There is a sensor on the side of the output shaft (Speedo).. Mine had become covered with metal crud and would not work,, pulled it out, cleaned it,..(replace the o-ring on the sensor!!) and it ran fine.. This might not work for you, but it did for me. Next.. take it too O'Reilly's, Auto Zone, or Advance Auto and ask the to scan you truck for a trouble code..(free) and see what turns up.. Good Luck..
https://shop.advanceautoparts.com/
Home Page Reilly Auto Parts
Save 20 On Online Ship To Home Orders Of 100 Or More

it ran fine? the transmission or the shifting worked fine? the engine or the transmission ran fine? - both? which it is?
Sounds like the problem may be the linkage to the transmission -- IF that is, the real problem is that you cannot shift the transmission?

Definitely sounds like a fuel problem. I'd change fuel filter and check fuel pump. If pump is running it could still be partially clogged. Try a fuel rail pressure test with a knowledgeable mechanic.

problems you described would suggest you need to replace the spark plugs, a bad one tends to fail under loads like going up hill. the other thing you could try is to get a better fuel grade, that would correct pinging noises uphill. and throw in some fuel injector cleaner every 2000km, it makes a happy running engine

check all lines and filters. berrydalewolf

well thats possible if it acts different at different temps you might want to check catalatic convertor and possibly your fuel pressure

shift linkage needs adjusting,,could be bent, easy fix, located along firewall to fram beneath the column, ask your son wut he ran over and didnt tell u about... hope i could help...:)

Hey buddy i have a 94 accord and i replaced the transmission and had the exact same problem. But it took me burning up the new tranny that was stuck in fourth gear on a hill to find out that the shift solenoids on the front of the tranny were bad. They are very expensive, so your best bet is to get them from a junkyard. Also i was told that my transmission control module could be bad, its located under the passenger side dash board, under the carpet. But luckily my problem was the solenoids, but i still had to put a second tranny in.