Saturday, July 7, 2012

Starter Ups and Emotional Roller Coaster!

Truthfully speaking, I am extremely excited to try and get the engine running, but at the same time I am fearful that it won't.  Yeah, that makes no sense at all!  I know. 
My good jeep went out of commission on Wednesday afternoon, so I have been down in the dumps about that one, too.  The transmission finally got stuck half in and half out of second gear.  It has ALWAYS had issues with second (like so many other jeeps) and finally it crapped out.  I singled the issue down to one of the synchronizer plates jumped out, thus not allowing any shifting to take place.  It took me about a day to narrow it down to that.  I have since decided now is the time to fix it (hopefully once and for all!) and new parts are now on the way.  Although that jeep isn't a part of the "Rustbucket" collection, I may just write about that torturous experience later.
Back to today's events...
I have returned to the scene of a previous disappointment...the starter cranking motor.  Previously, I haven't been able to get much, if any, action out of the THREE starters I have laying around.  The biggest issue I have had with them is trying to figure out if they are 6 volts or 12 volts.  I am setting this jeep up to be in its original 6 volt system, so Murphy's Law will determine them all to be 12 volt starters.
I am borrowing Jeff's Technical Manual 9-1825B Electrical Equipment (Autolite) to guide me throught the trouble shooting  process, since my first attempt a few weeks ago ended in a bust.
Starter #1 and the trusty (original) TM 9-1825B
Here is how starter #1 went down:
I disassembled it (again) and performed a series of tests that were practically identical with how I troubleshooted the generator (Spinning Genny 1/4/12).  I used the multimeter and checked for open lines and shorts in the case and the brushes on the top cover.  Everything checked out perfectly.  The internal brushes showed continuity to the positive screw connection; the same two brushes did not show a connection to the case; and the two insulated brush holders on the top cover showed no connection to the cover; and finally the two unisulated brushes showed continuity.  All is well.
I then measured the tension on the springs that hold the brushes against the commutator.  The manual says new springs should read between 42-53 ounces.  I came up with about 24.  I replaced them with my old springs from the good jeep.  They registered around 36 ounces.  That was better and should be fine for awhile.
Checking the tension on the replacement spring.  The reading is taken at the moment the spring allows the brush to be removed from the commutator.  New springs register between 42-53 ounces of tension, used springs should be slightly less.  This used replacement appears to be around 36 ounces.  This isn't great, but better than the 24 ounces I had on the others.
I then went through the armature (picture down below) and the commutator looking for shorts and none appeared.  Great.  It looks perfect.  Lets put it back together and make it spin.  I do it and all I get is a spark or two.  Hmmm.  I thought that perhaps I put the brushes in the the wrong holders.  No, I was correct in the install. 
That is when I saw my rookie mistake!  It was the exact same problem that got me when I fixed David's generator:  some of the insulation for one of the internal coil wires had been rubbed away, thus exposing some of the copper wire to the case.  This created a short.  I did not discover it when I checked with the multimeter because the wires were not connected to the brush holders.  Instead they were free and pointing upright.  When they are attached, they get crooked and cramped inside the case and this is when the exposed copper wire would short out against the case!  Bingo.
The exposed wire is shown.  It directly above the bottom of the rectangle opening.  When fitted into place, the exposed section would contact the internal metal of the case and cause a short.  I wrapped it up with friction tape.

I reassembled it all and tested it.  I got nothing against the battery charger at 6 volts.  However, when I switched it to 12 volts, it spun quite powerfully.  Now I'm thinking "Darn-  IT IS A 12 VOLT STARTER!"  It is fixed, but I can't use it.  I set it aside and move on to the next one.

Starter #2:
The next one had its own set of issues.  It looks to be in fine shape, though.  On the exterior of the case, it is stamped "REBUILT 4-23-86".  Internally, it looks GREAT!  Everything seems clean and all of the wires look secured.  Why the hell won't it work??  I went through all of the prescribed tests and everything checked out.  However, when I reassembled it, it would not spin at all-neither manually by hand or hooked up to a battery.  Upon a closer examination, I discovered that one of the bolts that attaches the Bendix Drive to the end of the shaft was a bit large.  As a matter of fact, it was so large that it would bind in the interior of the casing.  A-HA!  No wonder it won't spin:  there isn't enough room for the bolt in there.  Well played, sir, whoever you might be that rebuilt this starter back in '86!
I didn't have a spare bolt to fit, so I removed the oversized felon and grinded it down a bit on the bench grinder.  It seems like I took a lot off the top of it, but it still wouldn't fit properly inside the case.  I decided that since the Bendix is the wrong kind for my flywheel (and I have the proper sized one on order), I would remove it, assemble the starter and then test it to see if I can at least make it spin.

Wrong Bendix Drive with the massively oversized bolt that would bind inside the case.
 Oversized nut is on the upper right, just in case you don't see it.
Well, when it was hooked up to the power source, I got nothing.  Well, almost nothing.  It, too, would spin decently with 12 volts from a battery charger, but at six volts, it was quite dead.  Or was it?  It was moving, but barely.  Now that made me think:  Can a 6 volt battery make a 12 volt starter all?  Probably not.  So, perhaps this is a six volt starter. 
I disconnected it and tried turning it by hand.  It felt tight.  Perhaps when it was rebuilt, the four internal coils were not screwed in far enough into the case, thus they are sitcking out a millimeter too far and creating the resistance to turning?  It is a possible thought.  I tried tightening the four screws to the coils, but it was a fruitless endeavor.  I kind of anticipated that before I attempted.  Those screws will not budge.  Next, I diassembled the starter.
I wish I had taken a picture at what I had found, but I didn't.  When I pulled the armature out, it looked like there was a build up of some sort of sticky dirt/grease substance all around it.  I took some fine sandpaper and went around it, making it look quite shiny.  Hoping against hope, I hoped that I had removed enough "stuff" to free up the spinning action.  I reassembled it and tried it manually with my hand.  It did seem to spin easier, or maybe that was just my hope being hopeful.
Just so you know what the heck I am referring to, this is an armature.  However, it is not THE armature I am working on.  After I cleaned up the correct armature, I assembled it.  And then I thought, "Man, I shouldn've taken a picture."  This is another one that is sitting on the workbench.  The area that I sanded are the many horizontal silver rectangles along the fat part of the piece.

This is the aftermath of my sanding.  The sandpaper was new and all of the black funk came off of the armature.
I hooked the starter up to the battery charger and it really didn't do anything at all.  I switched it over to 12 volts and it spun faster than the other one!  I then read online that battery chargers sometimes do not deliver enough amps to make it spin and that it will often appear that it has a short.  I took a pair of cables and attached the starter to my 6-volt battery and...

...IT WORKED ON 6-VOLTS! Now, I need to get that new Bendix...

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