New to me van, Original owner and previous previous owner used the 4wd but the previous owner didn't. The front axle shifter had some significant side to side play (similar to my Toyota T-case shifter in 4H) so I figured since it was in neutral, that might be natural. When I tried to shift my front axle into gear for the first time (slowly rolling fwd), the stick flopped backwards with almost no effort and fell through the floor
(well, not all the way through, the shifter ball caught it on the boot...)
I got under there and saw that the shoulder bolt on which the shifter lever pivots had twisted off where the threads meet the shoulder. By the looks of the rust on the broken face of the bolt, this failure had been coming for a while and I just finished it off.
The bolt is pretty obviously seized in the linkage block. I can sort of get to the bolt head by taking off the shifter boot. I also had to remove the shoulder bolt from the rear axle shifter so I could get that lever out of the way.
That bolt isn't seized yet, but it sure is creaky. I coated the whole area in PB blaster and tried to knock the bolts out, but they're in there pretty firmly. I might try heating it up as the aluminum linkage block will expand faster than the steel bolt.
I'm contemplating pulling the T-case and fixing the linkage on the bench, but dang, that seems like an extreme way to do this. Anybody ever seen this problem before? Anyone got a better idea of how to get those bolts out of there?
Related but tangent: This seems like a funny choice for the design of this joint. The shoulder bolt goes through a stationary block and threads into the shift lever which moves. The bolt turns with the shifter. There's nothing besides the thread preload to keep that bolt screwed into the shifter. If there's any friction between the shoulder and the linkage block, it seems like that would slowly unscrew the bolt. Besides coating the shoulder with anti-seize before I put a new bolt in, I might try to find a bolt with longer threads and cross drill it so I can put a castle nut and cotter pin on the outside of the shift lever.