I usually hang out on the 80-86 forum as I have two 81 4WD F150's. The one I'm working on here has an NP435/208 combo. When I got it there were lots of problems, including the front drive shaft being in the tool box. I've now fixed a lot of the problems, including having the front drive shaft rebuilt since it was badly worn out, but now I need a bit of NP208 brain-storming.

I have a problem where the front output doesn't come into play unless the t-case shift lever is between positions. More specifically, to get 4 Hi you have to be between 4 Hi & Neutral, and to get 4 Lo you have to be between Neutral and 4 Lo, and those are fairly narrow places where it works.

Seems like a shift fork alignment or internal linkage problem as it appears to be moving things internally. With it on the lift and the rear drive shaft off I can tell that I'm getting 2 Hi, 4 Hi, Neutral, & 4 Lo, in that order. But, the only time the front shaft is engaged is in the between positions. And, the 4WD switch does show it in 4WD in not only the detented 4WD positions but also in the in-between positions where the front shaft is engaged.

I'm looking for all the input I can get as I've not had this particular t-case apart. Thanks, I'm really looking for your help.