I own a Navara d22 08 model. When i put it in 4x4 it makes a loud clunking noise expecially when under load. Im not to sure what this is. It almost sounds like the transfer chain, but im almost positive it cant be as its never made that noise before and has been sitting in the shed for the past 6 weeks cause i broke my foot. I engaged 4x4 the other night and thats when the clunking persisted. I changed my front diff and transmission case oil and there was no exessive fragments of metal....