So update on this. I got the compressor back on and I still had the squeal. It ended up being the alternator pulley was seized. Try spinning the alternator fans by hand and if you can’t your pulley is seized. Parts cost me 30 bucks and was an easy replace. Bow she’s running great.
Well, the alternator pulley does have a built in one way clutch that does fail. Most people just replace the whole alternator when it fails (the \"clutch\" starts to slip, usually because it has gotten rusty).
Considering it's a LuK/F A G/INA part you have, the tolerances are going to be much stricter than a typical non-branded Chinese part.
Use some blue Loctite on the threads when you reinstall that alternator pulley.
I got the bosch alternator pulley kit from ECS that seems pretty complete so am hoping I am good on that front: As to why I have to replace the pulley, the pulley on these alternators is clutched and said clutch goes bad. Symptom being a perfectly fine charging voltage but a chattery sound tied to the alternator light flashing on the cluster. Did a ton of research on here trying to diagnose and this is what I've come-up with as a starting point.
You were right, it's sleazy easy! The toughest part was breaking the solid pulley nut loose. Even the 1/4" hop of the tensioner, at low idle, is gone. Dead smooth!
A Bosch alternator doesn't care which Bosch pulley it uses, be it a 70A, 90A, 120A or 150A. The shaft is the same 17mm OD for all of them. What matters is that the pulley matches your belt and application.
Here's the old pulley. You can see the center section just sort of let go and the outer section started to slip around the center piece... It's tough to see; but there are little tiny cracks along the inside of the out piece. You can also see a chip on one part... The nice, shiny new pulley...
Fortuner, Hilux, Innova using GD engines
1. Alternator pulley & bearing - could happen even to those below 80k odo. Sound can be traced easily. Should replace all bearings inside the alternator.
The pulley on my 2015 Golf failed last week, and I had oil (grease from inside the pulley, actually) all over in exactly the same location as your photo shows. Also, the protective end cap came off the end of the alternator pulley - I found it down below, sitting on the top of the plastic pan under the engine. With that cap missing, it is possible to look inside the center of the pulley and see the splines on the bolt holding the pulley on the end of the alternator. The bad news: VW does not sell the pulley as a replacement part, you have to replace the entire alternator, which is a $1,000+ repair.
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