Question about how to set the tension pulley (No. 1 idler) for the timing belt on a 3.0.

Quoted steps from factory manual:

1. Pry the No. 1 idler pulley toward the right as far as it will go and temporarily tighten it.
2. Install tension spring
3. Loosen idler pulley bolt to where the idler pulley lightly moves with tension spring force.

Couple steps here, put belt on, check timing marks, rotate engine a few times, then...

4. Torque the No. 1 idler pulley bolt (380 kg-cm, 37 Nm

What's the point of the spring? Just the intial setting? Seems like when the belt stretches, this tension pulley would need to have the spring pull it tighter. What am I missing?

 

Timing belts don't stretch much, so yes the spring is just for initial tension.

 

the spring is also there to save yer arse if the bolt loosens up as I found out when I opened up my timing belt etc...