I'm really trying to figure out what the heck is rattling on my truck now. First I had a bad idler pully then they gave me a longer belt and it sounded like rattling but it was the belt bouncing. Now I have 955K7 from Autozone on it and getting rattling sound. I even replaced the tensioner 7500 miles ago. Wondering if the belts they sell are just wrong size? 2k dakota 3.9 automatic with a/c. Here is the sound, I will get new video tomorrow.

http://www.youtube.com/watch?v=pbmW7WNe134

 

That sounds a lot like a bad bearing, and I doubt it's from the harmonic balancer. I think you have the right belt on there but something else is wrong. Maybe remove the belt again and check all the pulleys for play or wobbling shafts. Check the power steering and water pump pulleys for any movement in the shaft.

Jimmy

 

I have my kids this weekend so I will try to check it out. Wish some of you lived around lewisville tx or denton tx lol.

 

The parts that kinda looks like two teeth are clicking together when a/c turns on. Gotta buy new one soon.