noisey alternator

i,ve just replaced the knackered alternator with one i bought from LR direct.
everythings working but boy is this alternator noisey, only had it on a few days , but every time the engine is under load it makes a whirring sound and you can really hear it inside as well as out.

does this sound like i,ve got a duff unit , or is this normal for a replacement alternator

thanks all

Duff.

Should be silky smoothly silent when new, burring noise is reserved for when it's full of ****ty gritty mud!

could be the brushes wearing in - sometimes they are "clicky" when new.

Can't see it, alternators are bench tested in the factory to check output, would be mighty surprised if it took more than that to bed them in.

Besides, aren't alternators brushless because they produce AC?

darren m said:

i,ve just replaced the knackered alternator with one i bought from LR direct.
everythings working but boy is this alternator noisey, only had it on a few days , but every time the engine is under load it makes a whirring sound and you can really hear it inside as well as out.

does this sound like i,ve got a duff unit , or is this normal for a replacement alternator

thanks all

Click to expand...

possibly duff ive had a few **** ones

Mr Noisy said:

Can't see it, alternators are bench tested in the factory to check output, would be mighty surprised if it took more than that to bed them in.

Besides, aren't alternators brushless because they produce AC?

Click to expand...

They have brushes but only for the field coil and they use a slip-ring commutator so it shouldn't be clicky like a dynamo might be. As you say, the output from the main windings is AC and fed direct to the rectifier diodes.

Regards, Peter.

thanks guys , tick over is fine its noisey as soon as engine reaches over 2,000 revs in each gear and i think its getting worse .

just hopeing LR direct will send a replacement , and i can keep this on the road till it arrives , then ,ill return the duff one.

anyone here had any dealings with LR direct , this is my 1st , hope there ok

thanks chaps

I've bought from LR Direct but never had to return anything so fingers crossed they sort you out ok.

Just one other thought - did you check that the pulleys line up ok and that there isn't anything that could be fouling the alternator fan? Also, is the drive belt ok? I'm just trying to think of things that might be easier to fix than removing the alternator again! You can often get an idea of the cause by spinning the alternator with the belt off - worn or gritty bearings can usually be heard or felt like this.

Cheers, Peter.