Title says it all, I've reviewed the relevant pages in the workshop manual and other than the obvious it doesn't offer much beyond how to lift the belt off the pulleys which needless to say is rather generic. The Super V8 was a breeze, but on the X150 R, the belts are barely visable...

Anyone here have a go at it on their own?

 

I've done it, both belts, tensioners, idlers, waterpump and crank pulley.

I did post a bit of a write up with pics here in the forum.

 

 

When I was having the belt squeal problem I was able to change just the supercharger belt on it's own, and the supercharger idler pulley, without removing anything else off the car.

Getting to the supercharger belt tensioner to release the tension was just possible with a 2ft long breaker bar. I did have to remove the ties that hold the intercooler feed hose, and the hose next to it for the air injection system (don't forget to tie them up again!)
The steel tube for the air injection at the front of the engine needed to be bent a little to get the supercharger idler pulley on & off, the first time I didn't realise it could be bent a bit.

Getting to the accessory belt tensioner without pulling stuff off is not so easy, not from the top anyhow, I could only get at it from the bottom as I recall.
When I first looked at the belts job long before I did the pulley swap, I thought there was no way of doing the belts, idlers and tensioners without removing a heap of stuff. But it is possible... a terrible job to do, but possible...

 

Pull the radiator covers, the hood shocks loose and stand the hood vertical. Install some 8mm bolts through the locking holes and work from the top. Not horrible, especially if you have the car on jack stands so you aren't bending over so far. I did the water pump, T stat and hoses without too much grief. Hardest part on the belts is fishing it around the crank pulley.

 

I'm tyring to solve chirping bearings - SC idler or tensioner - and intend to also change a squeqky SC belt with 77+ thousand miles on it.

A number of UK suppliers (e.g. britishparts.co.uk and xjkltd.co.uk) are selling kits consisting of:
C2C37055 - Supercharger belt (grooved on both sides)
C2C37056 - Supercharger idler pulley bracket
C2C37057 - Supercherger belt tensioner (plain)
C2S46862 - Supercharger idler pulley (grooved).

From XJKLTD

I've confirmed with britishparts that this is the "correct" set of parts for my MY2007, VIN B10XXX XKR and from what I've read online, the double sided belt and a "flanged idler" was adopted as a fix for frequent squeaky belts on these early X150 XKRs.

The current (single sided) SC belt set-up makes sense (notwithstanding the sqeaks!). The crank pulley, the supercharger pulley and the tensioner pulley are all grooved - as they all run on the inside (grooved side) of the belt. The plain idler pulley runs on the outside (flat) side of the belt. All fair enough.

However, the new, apparently "correct", kit has a plain tensioner pulley and a grooved idler pulley. As the new belt is grooved on both sides, the grooved idler will run on the grooved outside of the belt (OK, so far), but the plain tensioner will run on the grooved inside of the belt.

This seems odd, especially as the plain tensioner will run against the grooved working side of the belt - the side that is doing all the work of transmitting the torque via the flanks of the Vs. Can't do the life of that new belt much good: the points of these Vs rubbing against the plain diameter of the tensioner. Would it not have made more sense to retain the grooved tensioner pulley, so pulleys on both grooved sides of the belt were ... well, grooved?

I'm not sure I want to change to a belt/tensioner set-up that doesn't seem right. Or maybe better to buy the kit, and fit the grooved pulley from my existing tensioner - then all the pulleys would be gooved, on both sides of teh double sided belt.

Any thoughts?

Many thanks.