Alternator Rebuild (long)

[Clatter]

Figured I'd throw up something 'useful' here for a change;
Instead of just throwing up..

See, there's this personal fondness here for German parts.
Somehow, it just seems worth it to me to go through some pain to keep the OG stuff alive.

Case in point here, an alternator (or two).

Now,
My local O'Reilly's has an alternator that supposedly fits our buses.
It takes the boot from for the bigger alternator VW offered, and rumor has it that these work..

But that would just be far too easy, right?


So here's where I'm going...

I'll say it right now; I have no clue about rebuilding anything electrical.
My wiring and electrical experience has just been harnesses and bulbs and fuses and things like that.
This is my first ever alternator, so please don't hesitate to verbally accost; I surely deserve it.

For the most part, things came apart easily enough..

On the left are some parts that have been going well,
And on the right is a similar alt from a 914.
(In case i need to go back and see what I'm missing, or did wrong..)
In the middle is my conundrum.. Back to that later.

We'll start with the good parts..

The pulley and rear cover plate got black powder-coat.
The fasteners went out to cad plating.
The front housing/cover got vapor blasted,
And,
Best of all,
The rotor got restored for me by Osuna's Auto Electric in Watsonville, CA.
They also soldered some new brushes in my holder there as well..


ANyhow,
They usually charge about $200 to rebuild an alternator.
Having them do the rotor and brushes and selling me the bearings was $150.
Shoulda just dropped it off and had it done..

But, of course, that would be too easy..


First question i have is about bearings.
The guys at Osuna say that these Korean bearings are the best available today,
and some China bearings were causing come-backs for them.
They had all of the stuff right there on the shelf!
Does anybody know where to get good German, say, SKF or FAG bearings?
Was going to start digging, doing Google-Fu, but maybe a Wise Wizard here knows where??

Here i went and had them replace those fine OG brushes that didn't even need it..

Here's where the crux of my problem lies:
How to get this un-soldered?

I tried using this little heat gun and tiny soldering pencil,
But,
As i might have guessed,
It wasn't near enough..

Who out there has a favorite proper soldering gun and/or kit?
With a couple of these here to do,
Might as well get a decent soldering iron..

How about a linky for alternator rebuilding?
Can i test those diodes with just a meter?

How to keep the heat from destroying things when soldering back together?

What to clean all of those windings on the stator?

Thanks in advance for any info you can throw at me.
I'm just diving in to this,
And in well over my head, really.

A guiding hand (or foot, even) would be most appreciated...!
_________________
Bus Motor Build

What’s That Noise?!?

[Hikelite]

I've had my Weller D51 for 15 years

Used them in electronics manufacturing, so when I needed one at home, that's what I got.

Great thread.
_________________
~Kevin

My 1968 Campmobile

[furgo]

Nice thread! Chiming in for the bits I'm familiar with.

[SGKent]

drop by frys and get the red insulation paint.
_________________
“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[busdaddy]

I usually use the big old black Weller with the dual headlights, but for heavy shit like that if it's not looking like it's going to melt before I cook whatever it's holding I break out the antique tools:

Yeah, I've got a pile of old school soldering irons, nothing else compares when you need big fast heat. Although I do have a few blowtorches kicking around I usually use the propane torch to heat them, I'm too lazy and chickenshit to spend the time to fire one up.

Long ago, before I realized that even in the old pre power tool days serious craftsmen worked smarter not harder by using good tools (and flea markets had treasures most people never recognized) I actually made my own heavy iron by mashing a length of copper pipe and folding it over on itself, then I sharpened the end and heated it with a torch. Not the most elegant solution, but it works, figure out a way to hold it though, copper is a really good heat conductor
_________________
Rust NEVER sleeps and stock never goes out of style.

Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!

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[telford dorr]

Now THAT'S a torch! Flaming gasoline and everything! Things were much more fun in the pre-OHSA days...

Look at the soldered connections here (just below the black positive diode plate):

See the three (unlabeled) wires coming from the stator assembly? Those are the only three wires you need to remove to test everything. I use a small sheet metal type soldering iron or a good 'ol Weller soldering gun for disassembly. Most soldering irons just don't have the heat capacity to get the job done. My temp controlled 60 watt Weller WP60 is barely adequate. What you want is a LOT of heat - but not that much temperature. 700 degrees F is plenty. But tip mass gets the job done.

Tin the iron tip, then carefully heat the wire junctions where the stator wires connect to the diode trio board:

Use a pair of needle nosed pliers to carefully loosen, unwrap, and free each stator wire. BE CAREFUL! The terminal strip they're connected to is made from bakelite, and is weak, brittle, and won't take much torque or force! Some people like to use a solder sucker or braid to remove the old solder first, then just unwrap the clean wire, but I find the old solder helps conduct heat into the joint. Try it both ways and see which works better for you. In any event, once the wires are off, remove as much of the remaining old solder as possible.

Once the stator wires are off, you can check all of the diodes with an ohmmeter. If they're all good, even though they are still connected together, they will show conduction with only one polarity of the ohmmeter leads. The opposite polarity will show infinite resistance. (Note: use the 'diode' ohmmeter range, if your meter has one.)

More diode pics:

From the other side:

Should you need to replace them, and can find individual replacements, the six big diodes are pressed into their mounting plate with an arbor press from the flat side. They press out the other way. The positive diode plate is usually replaced as an assembly. Note: the three positive diodes have the opposite polarity of the three negative diodes - don't interchange them. The small diode trio diodes unsolder, or are replaced as a module. Do a sanity check with the ohmmeter before soldering the stator wires back on. Use rosin core 60/40 or 63/37 solder only.

The fun part is getting the brush holder reinstalled and the rotor back into the case. I used a short 2" length of coat hanger wire or welding rod to hold the brushes into the brush holder frame by pushing the brushes into the holder, then snagging their lead wires, holding them in. Once everything is reinstalled, you can carefully pull out the wire, setting the brushes free.

Other pics:

Test stand:

_________________
'71 panel, now with FI
'Experience' is the ability to recognize a mistake when you're making it again - Franklin P. Jones
In theory, theory works in practice; in practice, it doesn't - William T. Harbaugh
When you're dead, you don't know you're dead. The pain is only felt by others.
Same thing happens when you're stupid. - Philippe Geluck
More VW electrical at http://telforddorr.com/ (available 9am to 9pm PST)

[Clatter]

Beautiful.. Thanks for the pointers, fellas.

Think this thing would get those big three terminals(?) un-soldered?


https://www.amazon.com/Weller-D550PK-120-volt-Prof...dering+gun
_________________
Bus Motor Build

What’s That Noise?!?

[telford dorr]

200 / 260 watts? Yup - that'll get it. Just make sure the tip nuts are snug and making good contact. Just make sure you don't ever drop it - bakelite case. Brittle. (Ask me how I know...)
_________________
'71 panel, now with FI
'Experience' is the ability to recognize a mistake when you're making it again - Franklin P. Jones
In theory, theory works in practice; in practice, it doesn't - William T. Harbaugh
When you're dead, you don't know you're dead. The pain is only felt by others.
Same thing happens when you're stupid. - Philippe Geluck
More VW electrical at http://telforddorr.com/ (available 9am to 9pm PST)

[Silverboot]

can't help out with soldering or electrical, but those bearings look exactly like skateboard wheel bearings, if you cruise by your local skate shop you could see if they have swiss or ceramic, and make sure they are the same size. They will be packaged in 8's, but you said you have a couple to do.

https://bonesbearings.com/bones-reg-swiss-skateboard-bearings-8-pack

Scott
_________________
79 FI CA Riviera
74 Smallframe Vespa

[Hikelite]

[tootype2crazy]

https://www.amazon.com/gp/product/B00G9GWANE/ref=oh_aui_search_detailpage?ie=UTF8&th=1

One of my favorite tools for automotive wiring. Tiny, adjustable pinpoint flame. I use it for big chunky soldering and to shrink heat shrink and terminals. Powered by butane and easily refilled.
_________________
air-cooled or nothing for me
1978 Sunroof Deluxe Bus (daily driver)
1978 Transporter (mom's, making into a camper)
1970 Single Cab 2.1 turbo/EFI 6 Rib, 78 front beam, vanagon backing plates on rear (project)
2001 GTI VR6 (wife's)

[Clatter]

Went by my friendly local hardware store,
They had a 100/140 Weller gun for sale,
And it worked a treat!

Stuff just popped right apart..

So, how to properly clean the stator assembly here..?
Solvent tank?
Bead blast?

Does the red insulation paint go on afterwards?
With the surfaces adjacent to the rotor clean and paint-free, right?


This has been actually kinda fun so far..!

Thanks again for the excellent info Telford,
Very much appreciated.
_________________
Bus Motor Build

What’s That Noise?!?

[busdaddy]

Don't bead blast that stator, the red color on the wires is insulating varnish, remove some of that and they might get freindly with each other in a not so good way. Solvent or maybe brake kleen (if it's the stuff that doesn't dissolve the varnish) to clean and degrease (solvent and compressed air has always worked for me). Then perhaps tape up the wires and carefully wire brush or wire wheel the exposed steel parts and give them a light shot of paint?
_________________
Rust NEVER sleeps and stock never goes out of style.

Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!

Слава Україні!

[TomWesty]

I wouldn’t use anything of a solvent nature or that is at all abrasive. I’d probably just use soap and water and a soft bristle brush. What’s the word from Telford?
_________________
If you haven't bled on them, you haven't worked on them.
Visit: www.tomcoryell.com and check out my music!

[Tcash]

electrical parts cleaner
https://www.google.com/search?q=electrical+parts+c...p;ie=UTF-8

Good luck
Tcash

[telford dorr]

My inclination would be to leave the stator alone. That enamel insulation is 40 years old and likely can't take a joke. Yeah, it looks nice when it's all clean and shiny, but I'd resist that temptation, as it won't improve performance or reliability one whit. Even the steel laminations making up the stator core have varnish on them so they don't short to each other (otherwise, the rotor will induce a circulating current into the core, causing severe losses, which is why the core, like all AC motors, is made up of insulated laminations, not solid metal).

Do inspect the stator carefully for burned insulation, bare spots, etc. There is a flying splice where the three coils which make up the stator come together. Make sure this isn't touching anything, causing a short. A small length of shrink tubing over it would be nice.
_________________
'71 panel, now with FI
'Experience' is the ability to recognize a mistake when you're making it again - Franklin P. Jones
In theory, theory works in practice; in practice, it doesn't - William T. Harbaugh
When you're dead, you don't know you're dead. The pain is only felt by others.
Same thing happens when you're stupid. - Philippe Geluck
More VW electrical at http://telforddorr.com/ (available 9am to 9pm PST)

[Clatter]

OK,
Spent a bit of time with this..

The diodes al check out fine.

Washed the parts all down with some gas and a toothbrush;
Didn't dunk it under, just dip a toothbrush in gas and scrub it down.

It got hosed down with brake parts cleaner and compressed air.
Hit the OD of the thing, where the red paint was flaking off all crusty, with a wire wheel.

Also masked off the diodes and label for blasting..

So,
Should the entire stator get hosed down with that red insulation paint?

Seems like they had the whole ting painted from the factory...?

_________________
Bus Motor Build

What’s That Noise?!?

[Clatter]

Something else...

On the stator;
Does the area facing the rotor get the paint cleaned off so it doesn't get insulated?

The electric shop cleaned off the area on the rotor that faces the stator.
Everything else got painted with that red insulation paint.

_________________
Bus Motor Build

What’s That Noise?!?

[Xevin]

What’s awesome about Clatter is that he asks questions up in here. I know him and his background. I totally appreciate him doing that in the Forums. The fact he spitballs here makes us better. Lots of knowledge. Like SGKent, Ray, Colin, Robbie, skills, cusser, and so many more.
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Keep on Busin'

[telford dorr]