C60s jumps out of fourth gear

[Bob Carriere]

....once the tranny is figured out the transfer case will need adjustment......

I can't remember how many times I took the running chassis to the back field for a test run only to walk back to the barn to get the tractor to pull the C15a back to the work shop...... tranny is usually the worn or pitted shifting bars, ball detent and springs......... the transfer case.... in my case the two speed T case.... was a real night mare........ and the adjustments of the rods have to be done one turn of the rod at a time.... and each time requires disassembly of the whole shifting mechanism... finally got it right and trouble free ever since....

good luck