Rockwell T221 Shift Linkage

[AlaskaK10]

Hi Everyone

I have been rebuilding the Rockwell t221 transfer case. I have it all back together now and all gears are turning smoothly as the should no discernable slop anywhere. Shift rails are in and move shift forks smoothly EXCEPT when I put in the poppet springs and balls and bolt down the lid with the interlock shaft. (What does the Interlock Shaft Do?? Now the shifter is very had to move in and out. I can pull the top rail out by hand barely but the lower shift rail only moves out if I wedge a 2x4 between the shift bar an case. I am wondering how hard it should be to shift this transfer case on the bench by hand. When I first took the case apart the shifters were frozen by old oil and rust so never tried getting it to shift so have no clue how hard these are to shift. I am going to set the engine and trans back in the frame and hook up the actual linkage to see how that works. If anyone has rebuilt one of these cases I would appreciate hearing from you with any info you can give me. There is very little on the internet about these old cases.