I test drove a 1984 k30 today and when I had it in 4 low and granny low and was turning a counterclockwise circle, at no particular intervals it let out a clunk under the body around the transmission. Was it trying to jump out of gear? The sticks never seemed to jolt back and forth. It never acted like it jumped out then back in because my circle continued smoothly and it didn't seem to happen in 4 high. Would this be a symptom of the transmission or the transfer case being messed up or could it be something else all together?