We replaced all the belts in my truck today, and we noticed something odd about the belts. The half of the belt going from the center of the engine to the accessory (e.g., alternator, compressor, etc) would be perfectly stable, but the side of the belt going from the accessory to the center of the engine wobbles noticeably.

We tried tightening the bejeebus out of them, didn't seem to make much difference, so we just set the belts back to what looked / felt more reasonable.

At least 3 of the belts have the wobble, the odd one out being the alternator -> vacuum pump belt (I'll double check tomorrow, but I think it doesn't wobble). The rest, only one side wobbles, and it's the same side on all of them.

Normal? Not normal? Video needed? Seems rather odd to me.

 

normal. it is a long distance with nothing in there to keep the belt from moving, so it develops a bit of a harmonic.

don't make the belt too tight, or you will eat the bushings in the alternator.

 

It's fine. The most tension is between the drive source and what's being driven, so that side will always look straight. The other side will have less tension on it which is what makes it look loose.

 

Awesome, thanks you guys