Some notes on reworking the VW generator

To dis-assemble the generator, I loosened the two long bolts that go all the way through the generator, end to end.  I left a full thread engagement into the end cap and I broke the end cap loose buy  tapping the slotted end of the bolts.  This made a nice gap to insert a couple of pry bars in between the end cap and the generator body.  I just tapped on the end of the armature shaft with a bronze hammer until it slid out from the bearing.  I did almost the same thing to the opposite end.

Next, I released the springs that apply pressure to the brushes and I loosened the screw that connects the end cap to the electrical contact in the body and the whole assembly just slid apart.

I removed the two screws that held the bearing into the end cap on the fan end and the cap came right off.  Next I pulled the bearings off the armature shaft using a small puller.  They were not on very tight, they slid right off.

I sprayed all the parts with cleaner and pushed the bearings back on the armature.  I just reversed the disassembly process and it was back together and ready in no time.

I used a piece of 400  grit sandpaper to clean the commutator.  Make sure there are no burs left that can cause excessive ware to the new brushes.
Pay close attention to the brush spring positioning upon reassembly.  The coil spring should be positioned so that pressure is applied to the center top of the brushes.  This applies a nice straight even linear pressure on the brush so it is being pressed against the commutator.  Be sure to check the travel of the brushes to be sure they do not bind.

A couple of notes here, this procedure applies to a generator that was previously working, it just needed the bearings replaced.  The coils were fine and the generator produced power, it just had noisy bearings.

It really isnt possible for a DIYer to repair bad windings. The parts should just be replaced if that is the case.  Used parts are out there, just be sure they are good.

Be sure to polarize the generator before you reinstall it.  To do this, connect a jumper wire from the D- terminal to the ground screw. Connect a +12 volt DC source to the D+ and the D- terminals.  The generator should spin up like a motor.  Only allow this to run for a couple of seconds, that's all you need.  This magnetizes the iron/steel cores between the windings and the hysteresis in the system (trace amounts of magnetism left over in the plates) will allow the generator to produce power.  Generators that have been sitting for long periods of time will eventually loose their trace amounts of magnetism in the plates and will "forget" how to make power.  The polarizing  restores this magnetism and you are off and charging.
Good luck!

Spring Once-Over

First I would like to start out with an apology; it has been far too long since I have posted anything.  No excuses, just too lazy to get it done.  I will try to do better.  I have gone from ready to sell the bus to, I am certainly going to keep it.  I am pretty solid on the keep it decision at this point.  I do have too many projects going, but the bus still holds a special place in my heart.
I don't know why, but the weather this spring has been a gift.  Way too warm, way too early.  While the farmers are in a bad way, it does afford us an opportunity to dig the toys out nice and early. 
After getting the bus out of storage quite early this year, I noticed after driving it a few days that it was leaking a bit of oil.  I had just recently gotten back from a big engine builders show in Lansing Michigan a couple of weeks ago and I was holding a spiffy new electronic ignition module in my hand.  I have a Bosch 009 distributor all reworked ready to put it in and a nice new set of plug wires to go with it.  I also have a set of “J” tubes to install, a new Gene Berg oil pump cover that needs to be installed along with a drill and tap of the block for full flow.  My intent is to have a full flow oil filter system on the bus.  So, out came the engine!

It came out very easily.  It took me about 30 minutes just taking my time.  I mounted the stand adapter to the front end and my neighbor and I lifted it in place.  This is pretty nice; I have never had the luxury of working on an engine up on a stand.  I think it was worth the $40 investment and some welding to make that work.

Another thing that has bothered me about the last time I did this engine is that I had painted all the parts up nice and pretty and when I painted the bus, enough overspray got all over the engine to make it look like is was all hazy.  This removal gave me a chance to repaint all the tin ware as well.

I started in on the oil pump.  As anyone who has ever attempted this on an early bay knows, routing the hoses and fittings from the pump and block past the exhaust, through the cooling tins, past the pulley, around the supports is a major pain in the butt.  I spent the better part of a day and about $50 making this work.  (big drill bits and brass fittings are expensive!)

 

In between working on the plumbing, I sprayed the tin ware and it all had a couple of days to dry over Easter.  I got back at it the next week and while attempting to install the upright cooling shroud, I noticed a small “clunk” in the cooling fan.  After a bit of wiggling and Jiggling, I concluded the generator bearings must be bad.  I knew the generator was working fine, and I could not hear any bearing noise, but that clunk was unmistakable.  So off it came.

Better now than once it is in the bus I guess.  Parts are on order now.
Actually the generator was pretty easy to dis-assemble to get at the bearings.  It will give me a chance to clean the years of dust and crud out as well.  If you ever get a chance to dig into one of these, don’t use a strong petroleum based cleaner to do the job.  The problem is the windings inside the generator are delicate.  They are a series of, seemingly, bare copper wires all wound into nice neat coils.  This copper wire actually has a clearish coating to keep them from making contact (electrically) with each other.  This coating is a form of varnish.  Any solvent that will soften, or otherwise attack varnish is a no-no.  I think the best option is to stick to a spray can of electrical contact and parts cleaner available at most auto parts stores.
It looks like the generator parts will be here before the weekend.  That will be nice, as I would really like to have the engine all back together and put back in the bus this weekend if possible.  Hmmm.  That’s a tall order.