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Alternator Rattle

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jjbunn

jjbunn

Jedi Knight
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I pinpointed the source of the rattley noise from my '71 TR6's engine ... it's the alternator.

1665245038_3ac83288bf.jpg


Behind the alternator's belt pulley is a set of fan blades, which presumably help to cool the alternator. These blades rotate and rattle around a little. I noticed that the blades are free to turn in relation to the belt pulley: is that normal? Should I just apply some oil?
 
Julian,
The alternator fan should be fixed to the armature and not be able to rotate independently of the pulley. I can't tell you why this has happened or what to do to fix it but I'm sure someone who does will be along shortly.
 
The condition of this alternator sounds suspect.
Could the bearings be going bad?

Again, the right man with the most experience will
soon be along.
 
No, the fan should not rotate independently of the pulley.
It looks from the photo that the lock washer isn't compressed?
I think that pulley nut needs to be tightened?
 
eschneider said:
No, the fan should not rotate independently of the pulley.
It looks from the photo that the lock washer isn't compressed?
I think that pulley nut needs to be tightened?
Click to expand...

I agree. But I would remove the nut, pulley and fan to check out the shaft and the fit of those items on the shaft. If there was any movement of the pulley and/or fan, there might be wear on the shaft and/or the pulley and fan which might not allow the fan and pulley to ever tighten up for any lenght of time.
 
The shaft has a key slot groove with a key inserted. When the fan is installed it has a cut out to slide over the key. You the rotate the fan so the cut out is away from the key and tighten the nut. You can pull the alternatoer off in 3 minutes with 2 1/2 inch wrenches to verify this.
 
Julian, if you need it here is are a couple of links. The 1st one is the Bosch unit with the pulley for a straight forward change. The second is the home page for the company.They only sell wholesale but call them to find a dist. in your area.
Don

Well dang. The part PDF doesn't show right. Just go to catalogue and then Ford and then Fiesta.

https://www.pprok.com/

https://www.pprok.com/
 
roofman said:
The shaft has a key slot groove with a key inserted. When the fan is installed it has a cut out to slide over the key. You the rotate the fan so the cut out is away from the key and tighten the nut. You can pull the alternatoer off in 3 minutes with 2 1/2 inch wrenches to verify this.
Click to expand...

Excellent input: thanks everyone.

I removed the pulley and the fan. The nut did not seem to be on very tight. There is indeed a key slot, and a key inserted.

Why doesn't the key slot run the length of the shaft, so that the fan is engaged with the key? I would have thought that would prevent the fan rotating against the shaft even better?
 
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