I feel very foolish but I need some assurance. I am replacing the serpentine belt on my '99 XK8 (looks original with 144k). The old belt has the ribs up on the pulleys and the new belt comes out of the box slick side up. Makes more sense to me for the slick side to be up. Which side should be up after installation?
Thanks!

 

Should be self explanatory when you look at it installed - the grooves fit and align with the pulleys that have grooves whilst the slick side will be on the pulleys that don't.When observed from the engine compartment the slick or smooth side will be up. Take a careful note of the belt routing before removal - it's easy to get confused with serpentine belt routing - they are not always intuitive.

 

Groovy side in against the driven pulleys as stated above.

 

Thanks guys!!! Seems someone in the past put the belt on backwards, hard to believe it would even fit that way.

 

Even harder to believe it would stay on that way!

Graham

 

If by backwards, you meant the ribs up, there is always a possibility someone put one of the Top Cog belts on somewhere along the line- those were heavily marketed for a period of time although I cannot say I ever really saw any significant difference on the vehicles I used them on...

 

Thanks to everyone I have replaced the serpentine belt and all is good! Not a bad job at all, amazing that I did not have to remove anything except the old belt. Wish all the tasks on the Jag were this easy.
LaRue