WHat is the difference between an Idler Pulley and the belt tensioner?

Streetglower · 10-11-2005

Is there a idler pulley and belt tensioner or are they the same thing? Firestone told my best friend she needed a new idler pulley on her 98 V6 mustang, but is there an idler pulley as well as a belt tensioner or is it one pulley? I noticed on the belt tensioner on the v6 mustang, that there is a pulley where the ratchet goes to remove tension from the belt and that pulley is connected to another pulley, so which one is which?

Someone please explain this to me.

Joel5.0 · 10-11-2005

Some serpentine belt systems have to use an idler pulley for the correct routing of the belt. The difference strives in that the tensioner pulley is attached to a tensioner arm that controls....tension of the belt. The idler pulley is a fixed pulley used for routing purposes only.

Streetglower · 10-12-2005

so does the V6 mustangs even use an idler pulley? I have heard some sites say that the actual belt tensioner has the idler pulley attached to it. I know the tensioner is the piece that gives the belt tension. but others are telling me the actual idler pulley is the one that you connect the wrench too and move away from the belt to remove tension.

SO you are basically saying that the belt tensioner is completely different from the belt tensioner, correct.

Joel5.0 · 10-12-2005

Quote:

Originally Posted by Streetglower

so does the V6 mustangs even use an idler pulley? I have heard some sites say that the actual belt tensioner has the idler pulley attached to it. I know the tensioner is the piece that gives the belt tension. but others are telling me the actual idler pulley is the one that you connect the wrench too and move away from the belt to remove tension.

SO you are basically saying that the belt tensioner is completely different from the belt tensioner, correct.

Tensioner pulley is different from idler pulley. Based on the belt routing diagram I have, the V6 has both.
The tensioner pulley is the one attached to an aluminum pivoted arm used to remove the belt. If you use the wrench on the idler pulley, tension is not affected until you remove the bolt completely from the pulley, by removing the pulley, it is fixed to the frame.
They are two completely different pulleys.

Streetglower · 10-12-2005

ok thanks. one more question, in your manaul, does it say how to remove it. Do I need to hold the pulley with any tools while I remove the nut or can I just go ahead and remove it as is? And what is the torque spec on the idler pulley?

Joel5.0 · 10-13-2005

For the idler pulley, once belt is removed, just unbolt it, replace with new pulley and torque to 35-45ft.lbs. (not in the manual, just my rule of thumb). For the tensioner arm, the bolt should be torqued to 60-80ft.lbs and the pulley bolt to 35-45.

Streetglower · 10-13-2005

the belt tensioner has 2 bolts on it? I know there is an actual bolt on the pulley which is where the ratchet connects to to remove tension from the belt, but what exact 2 bolts are you talking about?