Alternator on 3GM30f making whinning noise

[Rigger]

Recently I've started to get a whinning noise particularly at low revs which I'm sure is coming from the alternator. It still seems to be charging OK. I assume it's the bearings which are wearing. It is a Hitachi LR 155-20 which appears to be no longer available. Is it likely to be repairable ,if not does anyone know the correct replacement?. If possible I'd like to avoid retiring etc. Cheers for any help

 

[JVL]

Take it to your local auto electrics shop or get one from, I think it's called the alternator and starter motor co on eBay about £120 from memory.

John

 

[Spyro]

Are you sure it's not the belt? Spray a bit of water on the belt see if it changes tone or goes away.

 

[JumbleDuck]

Recently I've started to get a whinning noise particularly at low revs which I'm sure is coming from the alternator. It still seems to be charging OK. I assume it's the bearings which are wearing. It is a Hitachi LR 155-20 which appears to be no longer available. Is it likely to be repairable ,if not does anyone know the correct replacement?. If possible I'd like to avoid retiring etc. Cheers for any help

In my experience a whining alternator normally means a failing bearing at the front end. That can be quite repairable: take off pulley, split case, press or push out spindle, press or push out bearing, reassemble with new bearing. I had the alternator for my 1GM10 apart today to add the Adverc brush connection and it looked very straightforward for a bearing swap.

On the other hand ... if the bearing isn't going as a result of an overtight belt, the whole thing may be on the way out, so it might be a better idea to replace the whole thing unless you are skint.