First Winter Project (Alt. Rebuild)

Yves

True Classic
For my personal challenge I decided to rebuild myself a Bosch 70Amp alternator (Bosch 0-120-489-874).

I bought on Ebay a used 70Amp alternator with the mention was "operating at the time of withdrawal"
For rebuild I bought the following parts:

  • Two ball bearings
  • Contact Slip ring
  • Capacitor
  • Bosch Rectifier series 489
  • Voltage Regulator Bosch Style
After disassemble the alternator I clean every parts and paint the casing also I clean up the stator and apply a little coat of urethane paint.
After I installed the contact slip ring on the stator.
I assembled all parts and now I have like a brand new Bosch 70A alternator for Kermit

PS. my old still working and keep for a spare part.

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First time

Yes Greg, it's my first time.

It is not really complicate, only need to be a good observer and have free time :hammer:.
 
Very nice work Yves

I have learned to respect the quality job of Yves whenever he takes on a project.
The transmission rebuild is another example of excellent workmanship.

Great job! :clap: :thumbsup: :pimp:
 
Yes the gray stuff is J-B Weld epoxy.
I thought so. JB will conduct electricity although the resistance is high. It has metal particles in it. The low voltage might not cause as much of a problem and if the wires were already insulated. I used JB to fill the grooves on a traction motor commutater and darn near wrecked the motor.
 
Should be fine...

on a 12V system.

I've taken JB Weld and (put my ohm meter on it's most sensitive position) tried to read continuity
and could not get a reading, cured or otherwise.
 
I have learned to respect the quality job of Yves whenever he takes on a project.
The transmission rebuild is another example of excellent workmanship.

Great job! :clap: :thumbsup: :pimp:
Yes I agree a very nice job indeed. I was just giving a heads up as I have had issues with JB weld and electricity in the past. It is good stuff for patching engine blocks and things but like I said it has metal in it and will conduct. Mix some up and put it on a magnet and watch it crawl up the side of the magnet. I do hope after all that nice work on the alternator it does not become a problem. I will gladly concede to being wrong if it will help.
 
Steel epoxy on magnets

Mix some up and put it on a magnet and watch it crawl up the side of the magnet.

I did this last year and the steel epoxy "spread itself" all over the magnet. :)

Though I have found it to be sensitive to magnetism, I've not found it to be conductive in low voltage applications.
The steel has too many encapsulations per particle to conduct with low voltage.
Higher voltages, I would agree could arch through it.

Unless the epoxy states it's conductive, it should not conduct with low voltage.
There are purposeful epoxies that are made to conduct.

There looks to be clear separation on both sides with Yves application, so I don't see it as an issue.
But I'm not the authority on it. Just sharing my experience working with it.
 
OK, I have cruzed a some electronics chats and looked at the JB web site. JB says it is an insulator. The electrical chats are back and forth with most saying JB is ok to use on circuits and others saying not a good idea. So as we have agreed and the general consensus on other supposedly more knowledgeable forums that low voltage/amperage is OK. You can sleep easier tonight Yves. Wait! is 70 amps considered low?
 
Dragongate and Bob,
when I rebuild that alternator I was very meticulous.

The Stator winding wires have varnish but to be safe I install also a heat shrink from winding to the slip ring contacts. It is not viewable hidden by gray epoxy.

With my "Fluke" Multimeter I measure the electrical resistivity between slip rings and frame armature of the stator and infinity Ohms (Full Open circuit), between the two slip rings I measured 3.8 Ohms and that normal (Winding).

Yves
 
When the PO pulled this part...

Did they then store it in a pot of water?

WOW what a mess... WOW, what great work you do!
 
Exquisite work, congratulations. I love to see these kind of restorations. I wish we people could be renewed like that !!! :wink2:
 
I will sleep very easy tonight ;-)

You can sleep easier tonight Yves. Wait! is 70 amps considered low?


I not doubt my rebuild alternator, I take all the measure with my Fluke Multimeter. Fluke is high quality Multimeter and don't lie ... I dont have any conductivity between winding and stator armature... I will sleep very easy tonight:geek:

The 70A unrelated issue
 
Alternator rebuild project follow up

After three months of monitoring, no issue the battery charge properly.

For people who are concern about conductivity of "J-B Weld epoxy" ... In alternator rebuild project, no issue. Working well:woot:
 
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