Also posed in 914club - I decided to replace the bearings in my alternator. Grand total = $8.00!

Follow along here: http://www.ephotomotion.com/914engine/alt1.htm

WOW! great write-up. do you have part numbers for brushes and bearings?

That's a really nice step-by-step set of instructions. But, since you have gone to all of that trouble, shouldn't you replace the diodes while you're in there?

Eric

Can you please post the specs on the bearings?


Excellent work.

I looked for the brushes - but was unable to find them. Mine looked pretty good, so I didn't worry about it too much.

I really don't know the answer on the diodes....

As for the bearings, I used a 6203-ZZ and a 6201-ZZ (you can do google or ebay searches on those numbers).

The brushes are avail. from NAPA auto. I don't have the P.# avail right now but if anyone needs it I can post it.

the commentator is avail new. . It's fairly easy to replace and not expensive.

When I rebuilt mine, all cost's combined, bearings, brushes and comm. was approx $50.

I did not look into replacing the diodes but I'm sure they can be replaced. If they where bad, you'd know it.

One thing I did was took sandpaper and lighty cleaned the armetur and stator sufaces and then painted them to protect them from rust.

Good write up, let us know how it works

Keith

The Diodes often fail. They need to be disconnected to measure.

Never use emery paper on a commutator or slip ring. The abrasive will embed itself in the copper and the brushes will fail much faster. I used to work at a company that rebuilt motors.

What's the proper way to test the Diodes? I'd like to try

To clarify, I didn't sand the comm. that the brushes ride on, I sanded the armeture with the windings

Hey guys,
I see im a little late to the party but im trying to find a link that shows a step by step alternator rebuild. The link above is no longer available according to its webmaster.
Any help is greatly appreciated.

http://www.ephotomotion.com/914engine/alt1.html

'l' on the end

Funny how one little "l" can mess things up. That is exactly the site i was looking for. I saw it some time ago but just could not remember where.
Thanks!

Nice write up, I've done my own beetle alt, but my fresh on the road /6 conversion the alt/reg no worky and I took it to a pro....

I still waiting, phoned this AM he was going to look at it this morning. still waiting....

Should have done it myself....

Bumping this up because I'm following @Van 's great write-up and am at the point of drilling out the front bearing backing plate screws. Before I do, I wanted to see if anyone has been able to remove the bearing without drilling. It sure looks like that's the only safe way to do it, but there's that mental hangup of not wanting to drill something that wasn't designed to be drilled. Anyone used an alternative method? I have a couple spare cores so am willing to experiment within reason.

TIA

So after I finished replacing the bearings, brushes and checked the diodes I slapped it all back together and took it to my local Advance Auto store for them to run a test for me. Amazingly they had the right clip to plug it up with. Once they spun it up it came up with a diagnosis that it fails to show a charge. The guy asked me if the voltage regulator was internal or external. I told him its external and his reply was that makes this a generator then and we cant test generators.

Ok so I asked my buddy his opinion since he works on lots of old stuff. He said just lock it down in a vise on the benchtop and spin it with a cordless drill hook the test leads to your volt/ohm meter and see what voltage it reads.

Bada bing bada boom! It put out 30 plus volts.

@Red76 do you remember where you connected the test leads for this? I'm not sure where to check with the voltage regulator not connected.

Thnx

My alternator/generator is from a 76. Not sure if they changed any over the years. Probably not. There should be a plug-in on the back of the unit with 2 terminals. You can use an alligator clip t either one of them and the body of the unit is the ground wire. You can see the fins on the pulley are designed to draw cooling air into the unit while running so spin it in the direction that would pull air into your unit. If there is no current from the terminal you choose just switch to the other one and try again. Should be something there.

Interesting, sounds like a different alternator model than mine. All the 914 alternators I've seen have 3-Terminal connectors on the back (D+, D-, and DF) and I've never seen one with cooling fins on the pulley. I did get voltage from one or two of those terminals but not much. My understanding is that the exciter circuit needs to be energized somehow to get the alternator to kick in to full output mode. I haven't found info on how to do that for bench testing though.

I had a similar experience with my FLAPS but only after being told over the phone that they COULD test an alternator with external regulator and making a one hour round trip to town to discover they could not. After rebuilding, all my individual components (rotor, stator, diodes) tested good so I just bolted it in and will test when the engine is connected.

Thanks for your help.