Ok, a new sound that probably should not be there!

I apologize for not doing more thorough research before posting this - My excuse is the snow and cold temperature, here in Madison, WI.

Approximately 5 days ago, my daughter said the car started to make a 'clicking' sound, when I was out of town last week. She headed straight home and stopped driving it. A well trained and experienced 'Land Rover Daughter'.

I jumped in and checked for error codes when I came home, using GAP IID Tool. No error codes. I also did a quick visual check - All seemed ok. I carefully went for a quick drive - Yep, there's an intermittent 'clicking' type sound. It may happen 3 times a second, may not happen for a few seconds, may happen once every 2 seconds - even at the same speed. Generally gets quicker the faster I go, however. And at a certain speed it becomes 'invisible', because the normal road noise is louder, and therefore hides it. Seems to be coming from 'outside' of the vehicle, underneath, more towards rear than front. Zero 'grinding' - I have experienced bad Wheel Bearings before. No change when turning sharply left or right. Happens when in Drive and when in Neutral, when moving forward. Have not tested in Reverse yet. Had a new Transfer Case fitted by dealership about 18 months / 15,000 miles ago. Changed Rear Drive Shaft (from Lucky 8) about 18 months ago. This 'clicking' is medium to high pitched. Almost sounds like tapping a metal rod onto a hollow metal tube - This leads me to believe a Drive Shaft issue (front or rear), or perhaps Axel Shaft issue? Or maybe I just have something broken that is hanging down from somewhere, and is tapping against a moving Drive or Axle Shaft? I guess there could be an issue with the internals of the Front or Rear Diffs, but the noise just sounds far too 'out in the open'. Can a Bearing ever make a 'clicking' sound if it's bad? Along with the total absence of a 'grinding' sound? Drives nice and smooth - No wobbles. No lack of power or weird gear change issues. I plan to jack it up tonight and remove the shield that surrounds a large part of the Rear Drive Shaft, for a closer inspection. Sidenote, I have zero experience working with Differentials, except that I have changed the Fluids in both front and rear. So I don't know what all of teh sounds are, relating to Diff issues. I have the Rear Locking Diff. I also have zero experience with Rear Axle Shafts - I did however swap out a Front Axel Shaft a few years ago, but that was because of a split boot, and a small 'grinding' sound (lube was replaced by dirt).

So, I guess the specific question is this - "What can cause an intermittent 'clicking' or 'tapping' type sound, probably somewhere within the Drivetrain?"

Hopefully someone has had a similar experience, to help me diagnose. Be gentle with me if you think it's something in the Engine or Transmission!

Cheers, Simon.

 

...could be the clutch packs wearing out. I've had this happen to my (locking) rear diff and it was a "clanking" sound. If you change out the diff make sure to change the locking motor too...they don't come new together.