I'd avoid WD40, it doesn't have the same penetrating release such as PlusGas for example. Spray on a couple of days before you do the job. Get the car to operating temperature and use 1/4" ratchet with extension bar. You just get a feel for the glow plug releasing under torque. If it's stuck, then ...

Come Brexit... will be lucky to get parts for your panzerwagon!

Meyle part here for driver's side. Pop out, and I'll fit!
https://www.ebay.co.uk/p/for-BMW-E53-X5 ... 1262264028

Just rear demist to sort and this car will be a keeper!

Get a little stepladder. I kid you not. This is me changing it my brother's X5 last winter. Been working on cars for years and never had to climb into the engine bay before! ::)

Interesting about reluctor ring. Had one break on my old Audi A4 V6 rear drive shaft. Straight forward to replace. Need a scan on the system to isolate the faulty speed sensor, and invariably will be a bu**er to remove.

Not long finished investigating a similar knock on my brother's X5. New drop links, lower balljoints and front lower track control arms and turns out the damper was goosed. Needed to be done and has tightened up the front end.

You can normally rule out the track rod arm by jacking up the car and ...

Definitely a nick in the rubber boot, so replacing the N/S boot at the weekend. The joint should be uncontaminated, so not replacing the joint. I've checked out a few videos online. Assuming everything comes off okay, is this straight forward to pull the driveshaft out? Only reason I ask is the ...

Haven't replaced the glow plugs on an X5 but changed plenty on Audis over the years. A word of caution, before attempting to remove, then spray Duck Oil penetrating release on the plugs a good 2-3 days before attempting the job. The next key thing is to only do the job if the car has been up to ...

[quote="x5e53"]
Very strange. Will get all bushes checked and diff oil checked/changed. Assuming diff oil can be changed in a 4.8is, some units are marketed as 'sealed for life'.[/quote]

Ignore the 'sealed for life' line. Audi quote that too on the rear diff on Quattro models. If it's approaching ...

As said mechanic on this project (aka brother with a garage) my money is on worn brake reaction bushes or the top mounts. The X5 is like a JCB in term of weight, so anything approaching 100k, you can expect deterioration in the bushes.

As an Audi veteran for the last 20 years the E53 is new ...