Try steerandgear.com
its under the steering column
On the internet - Google 1984 Dodge D100 PU.
7700
Spline end
i have a 87 but i think they are the same. mine is located right below the steering column.
The manual for mine says 22 gallons or optional 30 gallons.
one on the cross shaft from the frame to the engine
It is under the housing that the upper radiator hose hooks to.
Find a donor D100 that has P/S if that is possible. Disc brakes kits can be purchased. Click the link.
According to the owners manual: with filter change 1.4L (1.5qt).
The D100 is long obsolete
there could be a few reasons for this . the steering wheel splines could be striped , try turning he wheel and see if the steering rod turns where it goes into the the lower part near the steering box if not take the steering wheel off and check the splines on the column.. if it does spin there maybe the possability that the box is bad inside the gears may have split. - many of these trucks also used a system with a coupler on the gearbox that looks like a stamped steel socket, inside that socket are pieces that resemble "dog bones" often either the coupler itself is severely worn or the pin and etc associated with the dog bones are busted or worn, i would check this before attempting removal of the steering wheel itself. follow the steering rod from the firewall down to the gearbox and then attempt to manually turn this rod with your hand....parts for the set-coupler and the "guts" are under $50