Stupid question of the week.....

I believe '98 -'03 Supercharged XK / XJ cars were originally fitted with grooved belt tensioner pulley, and a smooth idler pulley.
(obviously, the grooved tensioner pulley rides on the inside of the belt, and the smooth idler runs on the backside of the belt)
Alas, when one goes to the hallowed halls of Jaguar Spares Dept., The *upgraded* replacement tensioner has a smooth pulley O.D., and the idler has grooves!

I don't see any way the belt routing can be reconfigured such that the grooved side of the belt runs on the idler,or that the backside of the belt can be made to run against the tensioner...
Did Jaguar Engineering, in their infinite wisdom, mean for the idler pulley grooves to run against the smooth backside of the belt, and the internal belt ribs to run directly against the now-smooth tensioner pulley??

 

In the later years, I think 2000 forward they reversed the pulleys as you described. You can buy a kit and replace the pulleys or you can find the correct belt in the aftermarket.

 

Thanks, Midlife.....

I did buy the kit from Jaguar (idler pulley, tensioner assy., and mounting bracket (the 'new' version is the only way they supply it, now) ....but am still up against the belt running on the wrong side...