Alright hive mind, been trying to do some self diagnostics before tearing into the truck after work this weekend. (2008 LR3, I know I'm a masochist)
Here's the deal, slightly noticeable grinding noise when rolling down the road from the front end.....
Gets more apparent at higher speeds, but does not get violent or anything.
More aggressive acceleration does not make it better/worse.
When driving down the road, lifting off throttle makes it either go away or massively quiets it. Step back on with any throttle and its back, so load related?
Turning seems to make no difference.
First thought was wheel bearing, now thinking it might be something as simple as low diff fluid in the diff, or possibly a larger problem with the diff? Maybe front driveshaft?
Just put all new pads and rotors all around so its not the brakes.
What would you look at first?
The load related part of your story suggests trans or differential troubles. Wheel bearings don't care about that kind of loading, but will get louder turning.
Front diff. Went through this about 2 years ago.. Sorry
To be more helpful... I'd suggest first of all draining the front diff oil and seeing what it looks like. If it looks suspect then it's highly likely it's started to fail and your only solution is going to be to change it. Depending whereabouts in the world you are, I found Island 4x4 to be by far the cheapest to get one shipped down to Peru
https://www.island-4x4.co.uk/axles-drivetrain-front-c-2404_4038_4039.html
On the UK Disco3 forum there is quite a lot of info on the front diff failures (amongst the many other failures!). You can also see some pics of failed diff bearings on my thread, if you really want to!
https://grassrootsmotorsports.com/forum/build-projects-and-project-cars/daily-drivers-in-peru-mazda-3-and-discovery-3-lr3/134498/page3/
Front prop failures also happen, but they don't tend to make a grinding noise. I'll admit, whilst I had it all apart I changed the front prop too as ours had quite a bit of play in the joints, and it made no difference to the shipping cost. Ours had around 210k kms on it when I changed it all, currently just over 230k kms.
