Ok, i just had my 4.10s installed about 4 months ago, everything was fine then i listened for any noise and nothing. Now when the tranny shifts into OD and i ever so slightly feather the gas pedal i hear a faint whine, doesnt sound serious at all but im currently swapping in some Royal Purple gear lube see if that helps! Ive been searching the posts and ive found some stuff on the fuel pump, ive read it may start to whine before it takes a dump, which ive been suspecting for quite some time. Ive had idle issues ever since i bought my car and the fuel pump is the only thing i havent replaced. Also on occasion when i feather the gas, it acts like its herky jerky like its getting enough fuel then its not, but under full throttle everything is fine. So how can i differentiate gear noise from fuel pump whine. The absoulute only time i hear the whine is when i feather the gas pedal.