Classic/Antique Car Repair/1950 Dodge B2B Truck
Would you happen to know the shift pattern for the 1950 Dodge Truck? It's a 3 on the tree and all I can seem to find is 2nd and reverse.
The shift pattern on a 1950 Dodge is the standard "H" pattern with first and second on top of the "H" (facing the driver)and third and reverse on the bottom part of the "H". There are 2 shift linkages on the bottom part of the column, one for each shift pair.
The short answer to your problem is that the shift linkages are out of adjustment. Causes can range from a simple adjustment to worn components to a worn-out steering column. On an old truck, the causes can be many. I'd recommend getting the truck up on a rack with an assistant inside and look how the shift levers on the transmission are moving in response to the steering column shift. You should see some free play somewhere: investigate and repair.
Hint: there a 2 gear pairs combined on 2 shift levers at the base of the steering column---one for first and second and one for third and reverse. Don't overlook the steering column and shift mechanism itself. You may have a build-up of tolerances due to wear that might not rule out any single component but combined create the problem.
For more information, refer to your shop manual but the preceding should get you started in the right direction.