Noisy alternator bearings....

[Frankd1]

I have a noticed for a while now what I believe to be noisy alternator bearings.
It occurs mainly when it's wet outside or there's lots of moisture - rain, snow, high humidity etc...it tends to get quiet as things heat up and dry out.

I removed the belt and spun the pulley by hand and I can hear the squeak.

Has anybody actually replaced just the bearings or do you just replace the alternator?
What is a good way to test the alternator and battery while still in the truck?

Here is what my gauge shows, I realize that these aren't 100% accurate...

 

[Sparky]

Good luck finding the parts to rebuild the alternator. With the amount of work and time it takes to redo the bearings it is probably just better to replace it and let someone else rebuild the core.

I had to replace mine when the bearings went out.

 

[Frankd1]

That's what I figured as well

 

[kickass audio]

Like previously mentioned just get a new alternator. If you have anything big for electrical strain like an aftermarket sound system or anything that can draw more power than your OEM alternator can put out i'd recommend getting a higher output alternator for example from mechman. The bearings on our alternators are molded into the casing, meaning that you can't just pound them out and bang in a new one. It is possible to do it but you have to use a dremel to grind away at the little lip that covers over the outer bearing race on the front and rear casing of the alternator before you can then hit out the bearing. The casings are VERY easy to crack, trust me, I had a bearing go on my aftermarket alternator and lost 2 ball bearings and the raceway was completely burned up and non existant. I for the hell of it tore it apart to see how bad it could be to replace the bearings (after putting my stock one back in the truck) and it was pretty difficult.

 

[mrrsm]

@Frankd1 ... Your 2004 GMC Envoy is on the list of vehicles that this inexpensive AD244 Rebuild Kit will service. The video shows a requirement for modest mechanical repair skills:

https://alternatorstarterrebuildkits.com/product/ad244/

 

[Enlightened1z]

Good luck finding the parts to rebuild the alternator. With the amount of work and time it takes to redo the bearings it is probably just better to replace it and let someone else rebuild the core.

I had to replace mine when the bearings went out.

I'm taking a 2400 mile road trip soon and was concerned that the one OEM part I have not changed on my 02 TB in the 12 years I've had it is the Alternator. I have 175K on the engine and wanted to know if you knew about when (mileage wise) our Alternators will go out. Do you recommend changing it prior to the trip?

 

[Sparky]

There is no rule really. I never had need to replace the water pump on my 02 TB in 215k miles, for example, while others have had to replace theirs perhaps twice in that time.

My alternator bearings went out around 115-120k or so, I think. But that was just mine.

 

[xavierny25]

Your on borrowed time with that alternator for sure. I often say don't fix it till its broke but then again your going 2400 miles so switch it out.

EDIT:I'm still running on my OEM but plain to change mine out this spring. The voy is just shy of 150k.