While looking for the cause of a occasional scraping metal to metal noise I found that the serpentine belt is out of alignment. It is running at the outer edge of the belt tensioner pulley & not centered on pulley. Looking down at the outer belt edge it is 3/16" out of alignment with the rest of the belt at the tensioner pulley.
I replaced the worn serpentine belt. Gates K060660.
With the belt off, the tensioner pulley ran smooth & I couldn't feel any slack/wobble in the tensioner pivot shaft assembly. It turns as intended. Can't find any problem with the assembly.
Air conditioner, water pump, and alternator all seem to be working properly.
I researched the archives and read the ogres article on this. Everything points to the tensioner assembly even though there doesn't appear to be any slack or looseness or wear or wobble in it to cause the alignment problem.
Do I need to replace the tensioner assembly? Or could something else cause the alignment problem?
belt alignment for tensioner is most likely worn tensioner arm pivot cause pulley to move under belt load. Even a small error can make the belt to move in/out on any smooth pulley.
Flat belt have odd rules and small issues can be a big headache. If you have vacuum cleaner that take flat rubber belt... look at beater bar etc "pulley" area... The budge shape is the why the belts stays in place. Car tensioners don't have the same "profile" and very easy to pitch a belt when to arm and/or pulley bearing are worn/bad. See http://en.wikipedia.org/wik...anical%29#Flat_belts https://www.lhup.edu/~dsima...cenario/crowning.htm
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
My tensioner did the same thing. The pivot was shot. Ended up replacing the entire assembly. You could easily look at it and tell the the pulley was out of whack but, strangely enough, it never threw the belt.
[This message has been edited by Raydar (edited 03-31-2015).]
Originally posted by Michiganman: ... What is a good source for a new belt tensioner assembly?
I'm tempted to say that they've made of unobtainium, but that may not be correct. I know that GM no longer sells them (or at least didn't), but they may be available in the aftermarket.
Edit - Found nothing but pulleys on eBay and Rockauto. You may have to find a used one. Try asking in the mall section of this forum.
[This message has been edited by Raydar (edited 03-31-2015).]
Originally posted by mike-ohio: Probably the pivot as already discussed. But, my A/C compressor was loose and the bolts required tightening. Just take a minute and check to make sure they are tight.
A/C can get loose but won't cause this problem w/ tensioner pulley.
V5 compressor can be missing brackets and bolts make problems worse. Missing brace/bolts on back AC unit is common for people replacing starter or fix exhaust. Examples: Morons think they know better then GM and leave parts off. People strip AC bolt holes or don't torque bolts and parts fall off later.
You can get a new one from the fierostore. Expensive but no one else has them and they are a nos part. Had one that was broken, discovered it when rebuilding the duke.
Thanks for the help especially theogre for his cave. I found and installed a used tensioner assembly. it corrected the problem. Back on track for a good summer in my t-top fiero here in Michigan.
