Hey everyone,

My 2004 TD5 has just started humming/whining when the throttle is pressed and it’s in gear.
The sound gets louder as speed goes up, around town I can barely hear it but on the highway it can be heard over the music.

Doesn’t do it in neutral (5 speed), stops the instant I release the throttle. Does it in low range but far quieter. Seems to only start once it’s up to normal operating temperature.

Front driveshaft looks good and has no play, diff, gearbox and TC fluids were changed about 6000 miles ago.

Any ideas?

 

You say it doesn't happen in neutral, so l'm assuming it doesn't happen at all while not moving?

Front driveshaft can "look" good...but the center cardan joint could be dry and worn. If it is original or age unknown...l'd drop it, lock center diff and see if humming/vibration goes away. Usually, a slight vibration/hum is the first indicator of a bad front shaft.

 

Correct, can’t get it to make the sound when not moving. I’ll drop the shaft today to see if the noise goes away, and have it rebuilt. As far as I can see it’s the original one.