Subject: My AC belt had at least 35k with no cracks... Author: ArbysNight : member since February, 2004 : 342 posts Posted on: 2005-11-08 10:57:07

You very well could be right about the cracked ribs being nothing to get up in arms about, but new belts certainly won't show cracks soon after installation.
I'm pretty sure my main serpentine belt was the original belt with 95k miles. My AC belt looked much better with no cracking. In fact, it looked just like the new belt I replaced it with, so it was probably fine. I've had my car for about 35k miles and I know that the AC belt hasn't been replaced, so that belt has at least 35k and isn't showing cracks. Based on those numbers, I'd guess a reasonable life for belts to be around 65k.
Therefore, I support changing belts when they start to show multiple crack near each other (like mine, or sooner!) Sure, a crack here and there is probably fine since the tensile strands are molded inside the flat part of the belt.

Arbys Night
2000 740i Sport
mreilley@hotmale.spelled.correctly.com

• Belt Replacement Instructions (Incl. Fan Removal) (pic) (url) - ArbysNight 2005-11-07 21:14:11 (34914 views)
  • Thank you! Excellent work! (nt) - JerrytheK 2005-11-08 11:34:59 (530 views)
  • I think you can drop the title 'non-mechanic', impressive work! (nt) - bavariancowboy 2005-11-08 10:15:21 (437 views)
    • Wait until you see my soon to be released 'Valve Cover Gasket Replacement' ;-) (nt) - ArbysNight 2005-11-08 11:00:25 (649 views)
  • Outstanding documentation-should go on E38.org David C. (nt) - Gary 2005-11-08 10:12:35 (416 views)
  • Wow, that looks like a lot of work. Nice Job....! - Magnum 2005-11-08 09:40:20 (404 views)
  • Nice! I'm working on a similar writeup for radiator (nt) - scottmm 2005-11-08 09:20:02 (360 views)
  • My belt shows cracks at 65k miles. Thanks for great write-up! (nt) - kend1606 2005-11-08 09:18:44 (458 views)
    • cracking or ribs does not always mean bad belt... - davidf 2005-11-08 10:24:00 (692 views)
      • My AC belt had at least 35k with no cracks... - ArbysNight 2005-11-08 10:57:07 (544 views)
        • All good advice, I'll examine mine carefully! (nt) - kend1606 2005-11-08 11:41:27 (357 views)
  • Great writeup. Thank you for taking the time to do so. (nt) - 740sporter 2005-11-08 08:57:25 (329 views)
  • Very nice! Put this in the hall of fame (e38.org)! (nt) - silber98 2005-11-08 07:46:12 (340 views)
  • Do this when you have the rad out - not so many skinned - rupertsona 2005-11-08 07:35:33 (466 views)
  • Good thing you replaced that belt - nice writeup and pics (nt) - beemer7 2005-11-08 05:27:56 (427 views)
  • Re: Belt Replacement Instructions (Incl. Fan Removal) - Socal7s Erik 2005-11-08 00:35:02 (686 views)
    • Do any of the pulleys tend to go bad or get rough edges? (nt) - Roy In GA 2005-11-08 00:38:42 (527 views)
  • Fan clutch removal tool (pic) - Claudio 2005-11-08 00:09:13 (1939 views)
    • nice job, very useful reference! (nt) - bimmer740il1 2005-11-08 10:58:11 (389 views)
  • What a god's send! Next to do list. (nt) - bmw635 2005-11-07 23:51:48 (343 views)
  • big wrench = 1-1/4 inch wrench for fan clutch nut (nt) - rhett 2005-11-07 23:46:43 (666 views)
  • WOW those are some nice pics and details socal 7's rock!! (nt) - itsstock 2005-11-07 23:43:51 (380 views)
  • Awesome write-up...2 questions: How long did it take, how much for the belts? (nt) - wcoleman 2005-11-07 23:41:40 (455 views)
    • Belts: $32 from BMA. Time: about 1 hour. (nt) - ArbysNight 2005-11-08 10:58:54 (612 views)
  • VERY well done. (nt) - WTH 2005-11-07 23:30:54 (331 views)
  • You are AWESOME! Excellent work. Thanks for sharing! (nt) - DavidC 2005-11-07 22:34:56 (325 views)
  • Great Write-Up!!! Very detailed and the pictures really help. E38.org for sure. - alfred 2005-11-07 21:49:39 (421 views)