I have been running the alternator on my 40 HP for over a year now. Granted, I have to rev it a bit to keep up with traffic (when I care), but I am wondering if the alternator is wearing out? At idle it makes a racket that sounds sort of like a bunch of crickets. It dies down when I rev the engine a bit. I don't get to hear my beloved fweem as much with that noise. Is it a sign that the alternator is getting ready to malfunction, that it is just "dumping" excess power at idle, that it is lugging... or what? The battery is good.
" At idle it makes a racket that sounds sort of like a bunch of crickets. It dies down when I rev the engine a bit."
A quick way to check the belt is to spray it with a bit of carb or brake cleaner while the engine is running. If the squeak goes away then it means the belt is slipping. I have had this problem in the past when I degrease the engine, it seems that the degreaser causes the belt to get glazed and start to slip a little even though the tension is fine. One quick fix is to take a bit of wheel bearing grease and work it into the sides of the belt over a section an inch or two long and then start the engine. It should make the sound go away.
If that doesn't help, try grabbing the fanshroud and push/pull slightly with the engine running. If the sound gets louder or goes away it means the fan is rubbing. You can usually loosen the alternator clamp and pull/push it and then tighten the clamp to remedy this. Another possibility is a bad bearing in the alternator itself, however if it's only a year old I would say that's probably not the source of your noise.
Alternator normally doesn't make any noise. Possible bad bearing (in the Alt)? The noise could also be associated with the fan. Rubbing? Debris in the blades?
If it *is* a bearing going bad, that could leave you stranded somewhere when it seizes up...
On 12/7/2004 7:15 PM Speedy Jim stood on a soap-box and preached to the unwashed masses:
Which brings up another subject. I have been reading, here and there, hither and yon, tales of woe about poorly-built replacement alternators. Rebuilt and new which break moments to weeks after installation. Is there a known good vendor or way to identify a good-quality alternator?
The best rebuilder is the person who will be using it in their car. They tend to care more. Study "how to" and do it using the same approach you've been using on rebuilding your alternator/generator.
Typically all the parts will be available for repair/rebuild. The hardest thing for most folks is cleaning up the slip ring area of an alternator, and the armature contact surfaces on generators.
If you know what a growler is, then you can probably do a fine job of rebuilding your own stuff.
Bearings are the simple part. But the most normally done poorly. I had an instructor in Aviation school that taught me a bit about "setting" a bearing properly. It requires a bench setup, but could be made fairly simply by getting a pully and belt and mounting the pulley to a bench grinder motor or the like. Just running it up to a decent speed and "setting" the bearing takes a few seconds, but can be the difference in a couple of hours of good service, and a decade of good service.
If you havea way to run your piece up on the bench , just tapping the housing around the bearing will true it up as it runs. makes a huge difference to durability of the bearing/s. Us ea small ball peen hammer for the tapping, and just work your way around each bearing for about fifteen seconds or so total time each bearing..............
I know it sounds too easy, but It works. I have only had two that I put bearings in and both outlasted the vehicles I did them for...........by years. Yeah, that's not many repairs like that, but one of them was in a bug generator. good results are worth sharing I'd say.
your mileage may vary
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Pardon the thread hijack, but I got a question about this. A ways back I was given an alternator that was missing it's brushes (the entire fitting that is) but had never been used in a vehicle. Not a bosch rebuild either, was a brand new unit. Since free and new is a damn good price, I didn't ask questions.
At any rate, I've made some spotted efforts in the past to get just the brushes so I could have a complete unit on hand as spare, with no luck. I dug up the plastic piece at one point so I'm almost there.
My question is if there is some "standard" to brushes that I could use to find replacements. Can I use anything that fits, if I find it?
Is there some readily available substitute that people commonly use?
Every business I've asked has basically told me to just buy a new alternator, which kind of misses the point.
Don't they have alt brushes on Aircooled.net or something? They do have generator brushes.
I have checked and it isn't the fan shroud rubbing. It isn't a belt making noise... although my "custom oil misting" feature is back even though I made sure the gen/alt stand, distributor, and fuel pump seals were in ship shape. Maybe the case breather hose is too stretched and is gunked up with sludge. But I digress.
The noise is definitely coming FROM the alternator. Another way to describe the noise is a rhythmic version of the sound nails would make in a coffee can when you shake it. Sort of a metalic cricket noise.... constant unless revving.
I am hoping that it is not dying because the receipt for the alternator is one of a very very very small handfull of receipts I don't have from ALL purchases over the past few years (I keep EVERY receipt).
we have gen brushes, but not alt brushes. You may be able to source what you need at an alternator rebuilding company (that's where I used to get mine).
I have a number of different Bosch brushes. At one time I needed brushes in a hurry and just bought a set at my local FLAPS. It's possible that no one will carry them anymore, but I suspect that you just haven't asked the right places yet.
Try looking in the yellow pages under automotive electric and call the nearest shop to see if they can sell you what you need.
BTW, are you sure you just need the brushes? Only the very earliest Bosch alternators used external voltage regulators; all the rest have an internal regulator which includes the brushes.
What's the Bosch part # for your alternator?
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----------------------------------------------- Jim Adney snipped-for-privacy@vwtype3.org Madison, WI 53711 USA
A distinct possibility, or I am not persistent enough. ;) I only get pushy with things that I can use a wrench on.
As sure as I'm gonna get.. the plastic piece that holds the brushes has no circuitry on it except for two push-on tabs that connect to wires inside the alternator.
It's a Bosch AL82N (N specifying new, would be an X if it was a rebuild).
That's rather odd. New Bosch parts would have a 10 digit Bosch part number. I thought that they only got the AL numbers when they were rebuilt. Bosch generally funnels several equivalent OE numbers into a single AL number when they rebuild them. None of my Bosch price lists show an N suffix for these. They are all X, like you say.
I have seen new parts come thru sometimes as rebuilds. This was explained to me as "priming the pump" when they ran short of cores. They still came with X on them, however. Odd....
At any rate, I would need the Bosch 10 digit alternator part number to cross reference a brush set for you.
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----------------------------------------------- Jim Adney snipped-for-privacy@vwtype3.org Madison, WI 53711 USA
Well I'll have to admit my claim is based on some googling I did last time I was looking it up. Since the internet isn't exactly a storehouse of accurate information what I know may be suspect. Without knowing better I accepted it as fact until better information could present itself.
Oh, if that's what you were driving at by asking for the number I would have held off posting until I got all the info. I thought you were just curious where the regulator was.
sorry.
Full part number is 9 120 080 122, it's Brazil made.
That number doesn't appear anywhere in my Bosch parts cross listings, but I DO see that number in the price list. There's no price next to it, however....
The best I could do would be to get dimensions from you, but I still think your best bet would be to take it (or just the brush holder) to an automotive electric shop and let them find brushes that fit. There's nothing magic about them; all you need is the right size.
German Bosch alternators used very few different brushes. I have just
2 or 3 different ones, and those may cover the whole range.
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----------------------------------------------- Jim Adney snipped-for-privacy@vwtype3.org Madison, WI 53711 USA
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