Transfer case issue

[EastonTexas]

I have a 1984 xj 2 door with a 229 am transfer case. I know the vacuum lines aren't right but sometimes going from drive to reverse it won't engage all the way and allow it to drive, it will just rev and grind and barely move. If you move the linkage with the diaphragm it will then catch and drive normal. I thought that was the linkage for 2wd and 4wd? It would make more since to me if it was in-between neutral and high or low but the linkage with the vacuum diaphragm is the one I moved to get it to engage...my first xj

 

[RCP Phx]

I wouldn't spend to much time/money on a NP228, but you need to fix all the vacuum issues before you can determine what might be going on.