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C15 Acert SDP

H621 · 2025-10-01 01:09

I have a C15 Acert SDP that is really making me scratch my head. It keeps shredding serpentine belts. The ac compressor pulley is slightly forward causing the belt to jump a groove on the fan hub towards the front. Ac compressor, fan hub, idler smooth, idler grooved, tensioner, and belt are all OEM and new. I also verified the esn arrangement to the ac mounting bracket arrangement #s and all is correct OEM matched. I'll try to add pics tomorrow. Any input?

Replies17
  1. #1pushbroom2025-10-01 02:15

    What truck is it in?

  2. #2chidog2025-10-01 03:08

    All pulleys have to be in almost perfect alignment, and no wobbling. I have also had mice or some critter chew on them as a snack. But not on a big truck engine.

  3. #3H6212025-10-01 06:36

    Kw

  4. #4H6212025-10-01 08:30

    Yes the belt started as full width.

  5. #5Vetech632025-10-01 09:15

    If a rib of a belt walks over the groove on the pulley then the belt will be compromised. Are you using matched up belts? They aren't as heavy as oem.

  6. #6Nige2025-10-01 09:19

    In addition to photos how about an enginne Serial Number.

  7. #7H6212025-10-01 09:20

    Yes oem everything.

  8. #8H6212025-10-01 09:20

    Sdp12073

  9. #9Vetech632025-10-01 09:23

    In your pic it looks like your belt tensioner is way off

  10. #10H6212025-10-01 09:35

    How so? Can you elaborate?

  11. #11Vetech632025-10-01 10:05

    The belt should go all the way across the idler and tensioner pulleys. The tensioner assembly looks worn and crooked in the picture, that will have a tendency to try and push the belt off. It may just be the angle if your pic bit it does look off to me

  12. #12Coaldust2025-10-01 12:18

    Good eye, Vetech63, I don’t think the alignment pin on the tensioner is engaged to the front cover. The tensioner is all wonky. It’s wonky, I say.

  13. #13H6212025-10-01 18:51

    The tensioner and idlers are new. The belt shredded and lost half the width which is why it looks like it's not going across the whole width of the pulleys

  14. #14Simon C2025-10-01 21:33

    It is the back side of the belt not the ribbed side that is getting eaten from what I see. If so it would have to be hitting a flat not ribbed pulley at an angle. Hard to tell anything when none of us are there. Keep us posted if you figure it out. Simon C

  15. #15eastroad2025-10-02 09:23

    How much time—hours or miles are on the vibration dampener ? If the belt flutters at running rpms that will amplify any promlems caused by misalignment.

  16. #16H6212025-11-05 22:47

    Problem resolved, I found the a/c compressor housing mounting holes had a sloppy casting not allowing it to set back far enough.

  17. #17Coaldust2025-11-05 23:15

    Thanks for the follow-up.