How do I tighten my serpintine belt?

[jackate]

I have a 1999 - 4.0 - XJ sport - 185,000

I need to tighten the belt but not sure of the best way to do it.

 

[the_weirdo]

There are two bolts - I believe they are both 15mm. Loosen the idler pulley, then loosen/tighten the adjuster bolt. Then tighten the idler pulley again to lock it in.

Picture stolen from someone else on this site:

 

[s14unimog]

And b/c its sure to come up next, my rule of thumb, on the XJ at least, for tightening the belt is to get just past an audible slip with the A/C on and working the tires back and forth.

Some people go for deflection but when you've had a component on the serpentine go bad, you'll see why to go after the least amount of tension you can get away with.

jsut my .02

 

[jackate]

Got it.. Thanks for the help....

 

[99XJK9]

Can someone please tell me if the adjusting bolt goes all the way through the bottom of the bracket? I loosened the bolt in the middle of the pulley and can move it back and forth. If tighten the adjustment bolt clockwise, it draws the pulley in. If I loosen the bolt it backs out through the top. Is it supposed to catch on the bottom and push the pulley out?

 

[87manche]

assuming it's a 99 4.0

you loosen the pulley bolt, then tighten the adjuster bolt. The tensioner goes underneath the serpentine belt. Tightening the bolt will draw it towards the manifold and take up the slack in the belt. don't overtighten it or you will replace an alternator soon.

 

[99XJK9]

Thanks for the quick reply. Just realized the belt was in under instead of over the pulley. Corrected and works fine.