Well I got this nasty belt squeal going on, has been for a while too. I haven't narrowed it down to which pulley but last time I heard something like this it was the alternator bearings in my '96 Mustang (4.6L SOHC) so I'm willing to bet its the same thing. Last time I had a shop overhaul the alternator for me. This time I'd rather do it myself if possible. But down time is an issue!

So, has anybody done bearings in these alternators? If so can you provide some info on what parts I will need? Of course, I'm very much open to suggestions on other possible issues or more common causes of accessory bearing sqeaul!

 

Take a long screwdriver and with the truck running place the tip on the
alt and your ear on the handle and listen to the sound it's making.
You can use this method to probe other places and see if you can'
narrow down the source of the sound. Or if you want to get a
mechanics stethoscope. Any local parts store should have some.



Sean

 

It's been a long time, but the last alternator I repaired (vs just swap out) was for electrical issues. I replaced the diode bridge and the brushes. I don't know if those are "user serviceable" on modern alternators. If they are, I would do the brushes while you have it out for bearings, since the brushes are a wear item. The diode bridge is not really a wear item, but can fail due to heat. I don't see any point in replacing it if it is still working.

 

Dropped the belt off and spun by hand positively confirming the alternator is the source of the squeak. Now to figure out how readily replacable the bearing is and which size... Doubt I'm lucky enough to be able to refresh the grease and be good to go.

 

i don't think you can do this yourself, never seen a modern alt. being able to be rebuilt by the do it yourselfer