Broken Alternator Bracket

[kbrandsma]

I was working on the Boxster this weekend. Oli change, fuel and air filters, brake line flush, and a new starter. My starter was making that terrible sound at startup. When I finally got everything back together and took it for a drive I noticed no power steering and the warning lights were all lit up on the dash like a christmas tree. I suspected a broken serpintine belt.

I removed the front cabin engine cover and sure enough the serpintine belt was shredded and had jumped the pulleys. On a closer look the alternator bracket had snapped. Here is a shot the bracket.

Has anyone had a similar experience with their 986? (similar threads on 996 but not 986). Are there other underlying issues. Loose bolts? Etc... All the pulleys and rollers seem free spinning. It's interesting because I recently had the alternator out three months ago to get behind it to replace the changeover valve.

Edited March 27, 2011 by kbrandsma

[Loren]

Usually cause is a bad pulley or idler - check them all for wobble or other damage.

[N41EF]

You didn't drop it or bang it around when you had it off? A cast part like that can crack if it is hit wrong, then once you put the stress on it it fails. Check one of the online salvages for a used alternator. I've had good luck with on in Oklahoma, and the one in LA.

Check all of the pulleys, and for any play in them. My water pump had a "wiggle" in it at 70k when I replaced it.

[stateofidleness]

You didn't drop it or bang it around when you had it off? A cast part like that can crack if it is hit wrong, then once you put the stress on it it fails. Check one of the online salvages for a used alternator. I've had good luck with on in Oklahoma, and the one in LA.

Check all of the pulleys, and for any play in them. My water pump had a "wiggle" in it at 70k when I replaced it.

Same exact thing happened to me when I tried to DIY my alternator replacement. Got it all put back together (at first glance) and the next day as I left work, I heard a high pitched squeal. Take the access cover off and the belt jumped and was cutting into the plastic shift cable protector. The alternator "shifted" in that horizontal bracket and the belt came off. I feel it was due to incorrect seating in that little "rail" and probably not tightening the bolt enough.