Question: Harmonic Balancer or Belt Tensioner?

[semperfih2o]

My 2000 C5 w/67k miles has started moving the serpentine belt forward on the belt tensioner after a few miles if I go over about 5000 RPM.
The belt is relatively new and the tensioner moves freely to put it back where it belongs. I've questioned my dealer in the past about the amount of wobble on the balancer and have been told it's normal. The belt will actually move forward about two of the grooves on the tensioner. Do these tensioners have any fore and aft adjustments? You guys have been great in the past and I appreciate any help you can give me.
Semper Fi, Robert

 

[gmjunkie]

My 2000 C5 w/67k miles has started moving the serpentine belt forward on the belt tensioner after a few miles if I go over about 5000 RPM.
The belt is relatively new and the tensioner moves freely to put it back where it belongs. I've questioned my dealer in the past about the amount of wobble on the balancer and have been told it's normal. The belt will actually move forward about two of the grooves on the tensioner. Do these tensioners have any fore and aft adjustments? You guys have been great in the past and I appreciate any help you can give me.
Semper Fi, Robert

No adjustments!! You need to get the balancer checked out,there shouldn't be any wobble!!

 

[semperfih2o]

Thanks gmjunkie, I kinda suspected the balancer but my "dealer" who would have had to replace it in warranty assured me it was ok when I inquired two years ago. As a side note a friend had his balancer come apart and it tore up the timing cover. I'm going to another dealer as I understand it is a real pain to replace if you can't get under the car.
Thanks again!!
Semper Fi, Robert

 

[c4c5specialist]

HI there,
I have to disagree here.
Wobble, on c5 balancers, are common place.
AND, there is NOT a runout specification from GM to accurately determine WHAT is good or not good.
My key is this, if your belt is MOVING, then the rubber may be allowing the outer rim to shift.
2 keys here.
#1, finding out if the balancer is ROTATING ON THE CENTER HUB>
#2, replace it IF THERE IS ROTATION

I would suggest to mark the balancer, both on the INNER and OUTER portion of the balancer from the rubber isolater. Then, note if its moved.
I have seen replacement balancers OUT OF THE BOX wobble, so do NOT be surprised.
Make sure you use a new bolt and torque correctly.
Allthebest, c4c5

 

[semperfih2o]

Thanks for the comeback c4c5, you just may have saved me much embarassment.
I stopped by another dealer yesterday inquireing about the replacement. I was quoted 4 hours time plus part cost. I was also told the part would be backordered until one was found. This being said, I marked the balancer and reved it and nothing seems to move between the inner and outer. I'm using a gatorback belt, should I replace it again?
Thanks again!!

 

[c4c5specialist]

HI there,
Movement will take time, and it wont happen instantly.
Most take a while to show.
That being said, a pully alignment check should be done to make SURE that the power steering pulley isnt installed too deep or shallow on the shaft. The pulley tip should be EXACTLY in line with the end of the shaft, not deeper and not further out.
Allthebest, c4c5