JB74 Alternator Whining

My 2022 JB74 alternator has started to whine, changing tone in relationship with RPMs.  I do not believe that it is belt noise, more towards pulley/bearings.  Less than 40k kilometers and only added a pair of DiodeDynamic driving lights to her. Besides going for a fairly deep swim a couple of weeks ago no other electrical changes made.  Any ideas?  New alternator or a fix?

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My 2022 JB74 alternator has started to whine, changing tone in relationship with RPMs.  I do not believe that it is belt noise, more towards pulley/bearings.  Less than 40k kilometers and only added a pair of DiodeDynamic driving lights to her. Besides going for a fairly deep swim a couple of weeks ago no other electrical changes made.  Any ideas?  New alternator or is there a fix?

Going out on a limb here but submersion is not good for the bearings especially if it's not particularly clean water. You may be able to get it rebuilt but it's likely going to be just as expensive as a replacement.

Depends on whether it is a whine, whistle or a whirring sound. they do whistle a bit when they are working hard.

A whirring sound is probably bearing damage caused by letting muddy water get inside as Lambert says.
It is possible to change the bearings, but can be a lot of trouble so a new one would be required.


In my younger days I took the series III to a quarry play day. I happily drove through a flloded hole that was so deep I had to wait until enough water got inside for it to sink so the tyres would grip and I could drive out.

I felt particularly pleased with my driving skills that day.

I was less pleased the next weekend when I found that the alternator was seized, the windscreen washer pump was seized, the heater fan was seized and the starter motor brushes were jammed with silt.


Now if the water is deeper than the tyres I drive round it, a half hour diversion is better than the time and expense of sorting out the damage.

The lesson has been learned! TicToc never shows "The-Next-Day" videos

Thank you Lambert and Facade for your guidance and input. I rolled up my sleeves today and took the belt cover off. Before I started loosing bolts I thought I would check again to see where the whining was coming from. Using a long handle screwdriver, I started with the alternator, placing one end on the component and the other to my ear, trying to isolate the noise. Alternator: no noise, Water pump: no noise, Idler pulley: squealing like a stuck pig! Several hundred dollar repair job was quickly reduced to less than 20 dollars.
Lessons Learned: 1- Stay out of deep water 2- dubble check before taking things apart.

Well done on finding it, never assume what is wrong. I once changed first the rear wheelbearings and then the diff because of a rumbling from the back. I even had a mechanic ride in the back seat to confirm it was the back axle. Made no difference, but when I changed a front wheelbearing that collapsed a few weeks later, the noise that was 100% from the rear disappeared.


If I were you, I'd take the rear drums off and clean up the rear brakes if there is mud inside.
And bring forwards changing the oil in the axles.


These vehicles will take you pretty much anywhere, but you have to pay for your pleasure by replacing things more often.

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These vehicles will take you pretty much anywhere, but you have to pay for your pleasure by replacing things more often.

And so the Wise Man has said!   .  This statement will be my motto from here on.