Checking alternator and brushes

I opened up my alternator this evening to get a look at the brushes to see if they were in need of being replaced. Once I had it open, I realized I really didn't know what I needed to look for. So, instead, I took pictures so I can ask the guru's here if it LOOKS like I need to replace them. Also, is it normal for there to be motor oil in this area? One of the bolts had a good bit of oil on it, and I think you can see som in the picture here even.

 

The brushes aren't in the photo ... they are mounted to the inside of that cover.

Look for a wear line on them. Or measure their length. 10mm is the low limit.

 

RickO - scroll the window.....

Brushes are in the picture. Wear marks visible.

Diagnosis: Practically brand new.

 

Those 2 black squares between the 2 screws on the cover aren't the brushes? And when I'm checking the length, do I measure the length of the whole thing (i.e. remove from cover and measure) or do I measure from the wear bar to the contact end?

 

MiCarl, aha, I was wondering if he just didn't see them. ;-) (I like big pictures, can't help it).


So, what about the oil question?

 

When I opened mine there was no oil.

 

I see MiCarl helped out we blind old farts, thanks buddy (rub it in a little will ya?!). I was puzzled by Rick's post as well seeing that they were right there, guess the coffee wasn't on time I guess. As for a little oil, I've got it too. New alternator seal and that will go away. About $8 as I recall. A little oil, no problem. More, not a good thing. It will mess with your brushes and by extension, the electrical system.

 

Not supposed to be oil in the alternator - you might want to pull the stator and reseat the whole housing assembly.

 

Another thought is how nice a photo this is to use to help folks find their brushes and what the wear marks look like.

 

Well, if I can't fix my bike, at least I can take pictures of it so others can see what to fix. ;-)

I'll look into the gasket. Of course, now that I know my brushes are fine, I'll have to go over all of the wire connections to see what's corroded to the point of the wires getting hot. Blast it, I was hoping it'd be easy.

 

It is a seal, not a gasket and it isn't that hard to swap, just have to pull the armature off the shaft. Special bolt for that but you should be able to find a bolt that will work at ACE.
Corrosion on the wires will cause this issue and the cure is replacement of the corroded connections and/or wires. Given the age of our machines and the technology of the time, this is an expected event for us all. I'm still looking at building my own harness but the breakout of cost is up there for just one harness. I'm still working this issue.

 

Oh ... Wow!
The Picture MOVES!!!
I can't get a picture to be the right size and you post ones that move.
Huh???

Well ... yep, them brushes are fine.

I would go get a couple of those pencils with the "Paper shredding eraser's" ... not the gum-rubber ones ... the gray ones ... with "Texture"

Erase the rings clean ... and wipe 'em off with Isopropyl Alcohol.
Clean-up the surrounding area and the inside cover with a rag moistened with alcohol.
Squeaky clean.

Button that alternator up and re-visit the scene after 25-hundred or 3,000 miles. If it looks like this after 3,000 miles ... THEN think about pulling-out and doing the grunt work.

Don't deliberately complicate an uncomplicated situation.

 

Robert, the seal that you are talking about, that would require me removing that big bolt in the middle of the ring there, correct? If so, how the heck do I get the whole assembly to not move while I try to loosen it?

 

I think if you have your display set to a lower resolution the ends of the brushes may be entirely off the screen. A higher resolution would let the whole picture be visible.

BTW - I am also a BOF. I think Rick counts as a blinder older fart. Or is he just using a Mac?

 

I'm a Blind, Old, Fat and going Bald Old Fart ... and, I'm learning how the Younger Generation's got it MADE.

I got a NEW MAC!

My daughter's iPod has more memory in it than the Dell we had before we got this.
I talk to my daughter on the computer! We see each other!

That's pretty cool!

 

Put the transmission in low gear, step on the brake and hit the bolt with an impact gun. It'll keep the motor from turning. Make sure you have a good amount of quality GREASE on the extractor bolt!

 

I just discovered that my XJ650J Maxim has oil in the alternator, lots of oil. Most of it appears to be older, perhaps the oil was overfilled in the past and that caused it to leak faster.

Anyway, I realize I need to replace the seal and brushes. It seemed appropriate to add to this thread as it already discussed much of the issue, and the original poster has had his questions answered.

There is a special bolt mentioned that is available at ace hardware - what is that for?

edit to add: answered my own question.

Their isn't as much oil as I thought. Once I removed the stator I found most of the assembly was clean, it just got sprayed around the front area by the rotor. Now that it's cleaned up I'll monitor it for a while to see if it leaks enough to warrant changing the seal.

 

I think there should be a very-small, little, "Notch" ... either in the Cover or at the 6 O'clock position, on the Engine Case, that is supposed to let-out any Oil that seeps through the seal.

When you park the bike on it's Side Stand ... you'd get a "Heads-up" that the seal was leaking by ruining nice pants with Engine Oil on the left cuff.

 

Ok...so no one really gave a straight forward answer on how to remove the stator. I'm curious to how this is done. I took my cover off and notice that there was oil in mine as well. Ok...

- How do you remove the assembly?
- What is the special bolt size
- And once you get this bolt, how do you remove it?

Please inform on what to do.

Thanks

 

Check that a leaky petcock isn't letting gasoline leak in. When I recently did mine, there was a small amount of gunk in there around the bottom screw. Then I noticed a gap between the gasket and the grommit for the wires where water or spilled gas could get in. My petcock leaks a liitle when the bike's cold and I move it to prime and the drips land right on top of the alternator. I suspect gas was mixing with worn brush carbon and creating this gunk. The old gasket was toast anyway so when I made a new one with Permatex Ultra Black, I made sure it sealed well around the grommit and added some in the gap on the outside as well. I did leave a small gap at 6 o'clock as a drain.

My brushes were in really good shape as well, but since I had the new ones and had it apart, I replaced them anyway.

 

I pulled the cover off my alternator to check the brushes and found a tiny biy of oil inside. The brushes look pretty good (thanks for the great picture).

I noticed that the gasket for the cover is cracked. I also have a leaky valve cover gasket that I'm going to replace. It's possible that the oil from the valve cover gasket leak (which runs down the engine) leaked into the alternator through the bad cover gasket.

Does anyone know a good place to find the cover gasket? I see an engine seal kit on parts4more, but it doesn't tell me what seals or gaskets it comes with.

 

Sure. That's possible.
But take a flashlight and look to see its not from the Seal on the inside Engine Case.

Clean-up the whole area.
Re-check it every so often to see if it was from the Top End or inside.

Be sure that the the Drain Notch is clean and clear (if so equipped.)

 

It may be possible the oil was in there due to the bike being tipped on that side too. I think this is what happened with mine. The oil in the alternator was very old, and there wasn't any sign of new oil when I pulled it apart.