I need to replace my alternator and need to loosen the serpentine belt. I have a chilton but where it tells me to loosen the tensioner with a 15mm socket a 15 mm socket doesnt fit so i want to make sure i am looking at the right bolt. on the tensioner there is a bolt with a star bolt in it then below that there is a another piece that is held on with a normal olt. which one do i loosen to let up on the serpentine belt. Thanks for any help!

 

the alt has bolts holding it tight on the front and on the back of it, you can see where the bolts slide back and forth in the little slots to adjust it. then theres the long bolt holding the alt on on the lower front. they are different bolt sizes. dont forget to unplug it first

 

I'm assuming you mean the center bolt on the tensioner...?

Just find the socket (use at least 1/2" drive) the fits the hex head in the center of the tensioner pulley (i think mine was 16mm), this is the one you need to "loosen." It doesn't actually loosen it, it just pulls the tensioner out of the way (if you've got a good tensioner, you'll be grunting) enough so you can slip the serpentine belt off. Then just slowly lower the tnesioner and proceed with taking off the alt.

One thing about the alt, is that it will be tight even after all the bolts are loose and taken out. This is becuase there is a spacer on one of the bottom bolts that stays tight even after the bolt is removed. You'll see what i mean... I just got my alt out with a GENTLE hand on a crowbar directly underneath it, and pop! Then just push or tap the spacer BACK into the hole to allow clearance for the new alt to fit in. It will retighten when you tighten the bolt through.