Rick512

just had alternator rebuilt, new bearing in fan( fan started hitting the fan housing, before I took apart, measurement at top was .014 clearance, bottom, 0. after reassembly, same results. both alternator bearing and fan bearing were bad when I removed. I attributed the zinging sound from the fan rubbing to those items, which is why I replaced. any ideas. have taken back apart, checked torq on all nuts and bolts. the alternator after rebuild does not turn freely like the fan.

71-3.0-911

When they rebuilt the alternator, did they change the bearings in it? This can also cause the fan to rub if the front or rear bearing starts to give. If the belts are too tight, they'll cause premature failure as well. I'd ask the shop that did the rebuild.

Rick512

guards red

Hi, the strap does not impact on the fan blade inside it's housing. That's down to the long bolts that run through the magniesium fan housing and out of the altenator and are clamped by a plastic cap at the back.

I think you need to check the housing is still round and is not oval through being crushed by the strap. Remove the belts to take the tension off the bearings, then measure all the way round with feeler guages keeping a tension on the fan blade in the direction being measured. hopefully this will rule out bearing play. You can also do that at the point it is rubbing and at the opposite point to that. That will help with bearing fun out.

Its possible that the housing has distorted.

Hope that helps.

Regards
GR

911PERVY

Slacken the strap off, it may work.

Rick512

pp000830

I have owned two 911 now with over 100K miles on the odometer and have never had a problem with the fan shroud dinging the housing or needing to replace an alternator or fan bearing.
Am I lucky or is it that I use care not to over tension the belts when I replace them?