how can we see anything in that munge? 1st thing you should do is clean out the box and re-grease it with a
small amount of grease around the forks and pawl, as much as is in yours hampers free correct movement and when it heats up can leak out the bottom .... there should be nearly enough space between the forks that the pawl can
not quite fit between them - the inside corners of the forks should be quite square, not worn round ....
see here, and a few pics previous in that album
you could have just pulled over when it jammed and [on level ground], reached under the hood and wiggled the arms from the box and got it back in neutral .... I believe the clamp on the rod that you moved, should have notches the bolts fit into, if you "lengthened" the rod, you don't have a bolt in a notch, so at some point the rod can slip in the clamp, up/down or turn, and give even more grief than you had before
what you should do to prevent it in the future is learn how to run the lever in a good H pattern rather than slopping the corners, especially on a quick downshift [you
are double clutching to pull it in first I hope] .... this has been a known problem since the trucks were new, probably 99% of the trucks represented here have had the shifter jam at least once
Bill
