10si Alternator Bearing Replacement?

Anyone replace a bearing on a 10si delco alternator? The bearing has started growling and howling....just trying to see if I can salvage the this one....

 

thanks

 

I found a local shop (that rebuild the generator for the willys) has the front drive and rear needle bearings and is willing to sell them to me for a $10 - I will verify the bearing number you sent - thanks....

Replacement looks pretty straight forward except the little trick of using a pin/paperclip to hold the brushes in against the spring while putting the two halves back together....The unit is only 5-6 years old, and I let the mount get wobbly....I fixed it but think the damage had been done....FWIW, I had to drill out and sleeve the bottom pivot/bolt hole to keep it from having too much slop....I used a bit of epoxy to hold the sleeve in place and you can see it squeezed out the end a bit....I tried swapping the 'new' unit from the willys which has barely been used, and it was doing the same thing....the sleeving worked great for a couple months until the bearing starting growling (not sure if its the drive or the needle bearing)....

 

Got it apart and the two bearings out....it was full of red dust...all the miles of red dirt roads in Utah guessing....


No number stamped on the end cap needle bearing, but the front drive bearing is 6203-4


I pulled the brush holding assembly and the VR etc to make it easier to drive out the rear needle bearing and clean up....that seems like more wear on the brushes than I was expecting for some reason....also, when I separated the cases, I expected the brushes to fall out, but a little white plastic piece was also floating around just under the brushes and I don't know what its for or where it goes - it the little piece in the upper right corner of the pic:

 

I do have the springs - just set them aside so I don't loose them or damage them....I'll see about brushes at the shop today - guessing it would come as an entire brush assembly/housing.

 

I marked the two case halves before separating to help ensure correct clocking - its a 3 o'clock position....I do have a digital multi-meter so see what I can test...there was no issue with functionality - I took it apart due to bearing noise, but can't hurt to check while its apart....

I got the new bearings and new brushes - the new brush came wire attached to metal clip so easy swap, and replaced one of the screw insulator that was cracked . The shop owner pressed in the new needle bearing for me just because he's a nice guy.

 

Hows this for a bit of a write up...sorry I wasn't really planning on it so I didn't get pics of the front half of the case with drive bearing and rotor etc....I mostly took pics of the confusing stuff that I wanted to make sure I got back together correctly, but ICYMI....

When you separate the two halves, the back half has the stator ring (wire coils - not pictured here, but is below) as well as the rectifier (rectangular finned thingy that changes alternating current to DC) as well as the dual plastic housing for the spring loaded brushes and the internal voltage regulator (this is a 3-wire unit), the diode trio, as well as a needle bearing cap that sits in the back of the housing....this is one of the two bearings to be replaced. You can also see the brushes are pushed out by the springs when the rotor is removed....


Here are the brushes up close (and the voltage regulator underneath and the diode trio on top):


One of the brushes in particular was worn significantly more than the other - usually that means a bad spring, but in this case its just kind of weird....but you can remove the brush with its metal clip and replace:


The other front half holds the pulley, fan, front drive bearing and shaft along with the rotor that spins inside the stator coils - sorry not pics....but here is the back half with new needle bearing installed, the new front drive bearing, and the brush housing....a paperclip or pin can be used to hold the brushes back against the springs until everything is installed.


Reassembly of the back half with new needle bearing in the bottom, new brushes, and stator ring in place:


I put the front half in the oven for 10 min with the bearing in the freezer so it slipped right in - no need to have to pound it in....


Assemble the two halves of the case back together...and you can see the pin that holds the brushes in has a hole through the back of the case that can be removed (pulled out) as the last step allowing the brushes to push against the rotor....


Sorry I didn't get pics of the front halve with the drive bearing and rotor - I wasn't really thinking about a full write-up - but its pretty straight forward. The front case half has a bearing in the front opening that the rotor shaft goes through, the fan and pully slide on the outside end of the shaft, and then you tighten it down with nut...

 

Yup