Alternator rebuild.

Hypnotoad

Original poster
Member
Dec 5, 2011
1,584
Does anyone have any experience replacing the front bearing when rebuilding an alternator? I've done a few in the past, but this Trailblazer alternator is a pain in the ass.

I was able to remove the bearing, but not without a lot of cussing and frustration. It took me a while to figure it out, but this bearing is held into the case with a rolled lip to keep it in place. I ended up using a dremel to to cut the lip off as best I could, then drove the bearing out finally.

My question is how do I install the new bearing? Will red loctite do the trick with nothing else?

You can see in the picture where the lip cracked off when the bearing was driven out.

IMG_0515.JPG
 

Dr.Fiero

Member
Dec 7, 2017
161
S. Alberta
Loctite/Permatex makes a specific bearing retaining compound. 2 part affair, where one get brushed on the housing, and the other gets spread around the OD of the bearing. It's... very... very... permanent, and can only be removed with a LOT of heat. You only have about a minute or less to set it in place. Then 15 minutes later - it's solid.

It was/is the factory method at Cummins for us to install the rear bearing into the housing of certain generators.
 

Hypnotoad

Original poster
Member
Dec 5, 2011
1,584
Any other ideas? Can't find any bearing retaining compound locally, and I need my car. Plus, it's REALLY expensive.
 

northcreek

Member
Jan 15, 2012
3,310
WNY
It looks like there is enough material there to drill and tap for three or four machine screws evenly spaced, possibly 6/32 or 8/32 thread.
 

littleblazer

Member
Jul 6, 2014
9,265
Could you not peen it in place? Could also run a little solder and braze it in place since it's an aluminum case...
 

Hypnotoad

Original poster
Member
Dec 5, 2011
1,584
Thanks for the advice, guys.

I ended up finding a very helpful YouTube video. I ended up following their advice and used red loctite and staked all the way around the bearing.

It was a bear driving the new bearing in, even with my 4lb mini sledge. There's no way that thing is going anywhere.414B6F5A-AD1C-47CC-ACC5-E16BF71CA44D.jpeg
 

Sparky

Member
Dec 4, 2011
12,927
So the question is, is the money saved over buying a replacement alternator worth the extra time and effort?

I didn't think so, so when my alternator bearing started screaming like a stuck pig I just replaced the thing. Well, was also my daily driver and had to get to work the next morning, so...
 

Dr.Fiero

Member
Dec 7, 2017
161
S. Alberta

Hypnotoad

Original poster
Member
Dec 5, 2011
1,584
So the question is, is the money saved over buying a replacement alternator worth the extra time and effort?

I didn't think so, so when my alternator bearing started screaming like a stuck pig I just replaced the thing. Well, was also my daily driver and had to get to work the next morning, so...
I used Amazon prime to order the kit, so I had to wait 2 days. That 2 day wait for the kit gave me time to figure out how to tear down the alternator. We were down to 1 car and it was manageable for us. I saved over $100.

I thought it was going to be easier. I've done a few in the past for different cars, but this one put up a fight. The things that made it more difficult are the front bearing and the fact that you have to desolder then resolder the electrical connections back togrther.

It was worth it to me, but I enjoy doing these kinds of things. I wouldn't hesitate to do it again, especially now that I've done one.
 

littleblazer

Member
Jul 6, 2014
9,265
The older 10si alternator was more rebuild friendly.
 

Hypnotoad

Original poster
Member
Dec 5, 2011
1,584
I've gotten a couple messages from people interested in how I rebuilt my alternator. So I thought I'd offer some tips for those that want to attempt this.

This is the kit I used. I found a discounted open box kit on Amazon and was able to save some money.
https://www.amazon.com/gp/product/B0031HHDUY/?tag=gmtnation-20

This is the video I followed.

The video is pretty good, except the part where he uses a screw driver to crack the lip of the cold rolled edge that holds the bearing was total bullshit. Mine was much harder to remove. In fact I used a chisel on the lip and the chisel cracked. I used a dremel cutting disc to remove that lip,as mentioned before,then was able to drive the bearing out.

One other thing I did was use a small torch to desolder the rectifier, then hit the molten solder with compressed air. That made the job very easy.
 
Last edited:

northcreek

Member
Jan 15, 2012
3,310
WNY
Good video, except the guy is a little too hammer happy and why would you cut the leads after you unsoldered them?
Removing the bearing retainer lip would be a lot easier if he just pulled the stator winding out of the case, one slip with the hammer and you've trashed the winding .
Still a good guide if you've never seen the inside of one of these.:twocents:
 

Hypnotoad

Original poster
Member
Dec 5, 2011
1,584
Good video, except the guy is a little too hammer happy and why would you cut the leads after you unsoldered them?
Removing the bearing retainer lip would be a lot easier if he just pulled the stator winding out of the case, one slip with the hammer and you've trashed the winding .
Still a good guide if you've never seen the inside of one of these.:twocents:

He cut off a terminal on the voltage regulator,is that what you're taking about? The newer updated regulator only uses one terminal instead of 2. So you can cut the unused lead off.

Good point, the windings just pull right out.
 

northcreek

Member
Jan 15, 2012
3,310
WNY
He cut off a terminal on the voltage regulator,is that what you're taking about? The newer updated regulator only uses one terminal instead of 2. So you can cut the unused lead off..
No I was talking about the three stator leads, as he's cutting them you can see that they are already unsoldered, so why cut them? and later have to bend the tabs down to meet the shortened leads. Like you said, just unsolder and blow with compressed air.
 

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