2002 Mazda 626 alternator belt keeps breaking

Tiny
JNURSEDEB
  • MEMBER
  • 2002 MAZDA 626
  • 100,000 MILES
Had the timing belt changed in feb. In sept. Had the alternator replaced. 1 week after having it replaced, it broke again. Then 2 weeks later, the belt broke again and the pully fell off. I don't know what to do. One guy said the timing belt cover was put on wrong and it was cutting into the belt. But if that were so wouldn't I have had alternator problems before then. No one seems to be able to fix it, any suggestions.
Do you
have the same problem?
Yes
No
Tuesday, October 8th, 2013 AT 9:48 AM

3 Replies

Tiny
CARADIODOC
  • EXPERT
Need some clarification please. The generator, (the term "alternator" was copyrighted by Chrysler, but that's nit-picking), has nothing to do with the timing belt. Which pulley fell off? Did a bolt come out or was it a pressed-on pulley? You said the generator belt broke but later you said the generator was replaced, then the belt broke again.

How did the belt break? Did it fray and unravel along one side or did it have a clean cut across it with no other damage?
Was this
answer
helpful?
Yes
No
Wednesday, October 9th, 2013 AT 1:58 AM
Tiny
JNURSEDEB
  • MEMBER
The generator pulley fell off, it wasn't a pressed on pulley, it broke with a clean cut across it with no other damage. The guy who looked at it when it fell off (we were out of town and took it to the first person we saw) said that someone put the timing belt cover on wrong and it was rubbing against the belts. Which is why I mentioned it.
Thanks
Was this
answer
helpful?
Yes
No
Wednesday, October 9th, 2013 AT 10:07 AM
Tiny
CARADIODOC
  • EXPERT
Dandy. I guess I could see the cover rubbing on the belt if it was mispositioned but it should have made noise and been noticed right away. I don't think that would cause a pulley problem though. That's asking plastic to cut steel. I don't know which engine you have. Some of them do not use a spring-loaded tensioner pulley for the generator belt. Those belts have to be manually tightened. I wonder if the previous mechanic over-tightened it after replacing the timing belt. That could stress the shaft on the generator and possibly lead to metal fatigue. Even that would be quite uncommon. In severe cases it's the bearings that would be damaged first from the excessive belt tension.

There could also be a totally different cause of repeat belt failure. That is one the components it drives is locking up intermittently. Normally you would suddenly hear a loud squeal unless it happens so quickly that the belt breaks right away. Generators have been known to lock up when a bearing fails. That's actually pretty common on GM vehicles '87 and newer.

If something else is causing the belt to stop abruptly, that could cause the generator pulley to stop spinning, and the momentum of the rotor might cause that nut to work loose so the pulley could fall off. I'm really tired now and not thinking clearly. Instead of thinking of every remote possibility, I'll check back tomorrow to see if you've made any progress.
Was this
answer
helpful?
Yes
No
Thursday, October 10th, 2013 AT 4:23 AM

Please login or register to post a reply.

Recommended Guides