Remanufactured alternator brush alignment

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Looks like they missed, badly. Surprisingly it worked fine for 4.5 years like this~25k miles, and often, it was told by my adjustable voltage regulator, to make everything possible towards its 120 amp rating, feeding a large depleted low resistance AGM battery, over a thick copper circuit. [Linked Image] [Linked Image]
 

wrcsixeight

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No idea where the remanufacturing occurred. http://www.wilsonautoelectric.com/PartDetails/Index?partId=ba0d2bbc-44d3-4735-8b83-a567746add93 This was an O'reiley's sourced lifetime warranty replacement, and apparently was the last one they will give me. It seemed more robust, output wise, than its predecessors, until that brush could no longer contact the slip ring. The NEW Nippon Denso Alternator currently replacing it, is disappointing in output at hot idle speed. I was led to believe it would be superior at hot idle, but it is not. Made in Malaysia, via AZ. I've not tested it for absolute max output, yet. but hot idle speed when brand new could barely keep up with loads at night, the Wilson had an extra 20 amps at hot idle for battery charging. I've lowered brush holder and am truing up the slip rings, and gonna return the Wilson to duty once I give it some more spit and polish.
 
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Can you buy a set of brushes separately? Replace the brushes and put it together properly this time it'll be good to go.
 

wrcsixeight

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Plenty of brush left. Its the brush holder which was too high. I lowered it so lower brush is below gap and the whole thing sits more firmly than before The top slip ring was way way out of round. Wound up spinning the rotor using a wire wheel cup on the Dual v belt pulley, using an angle grinder slowed way down via a Router PWm motor speed controller Freshly disassembled: [Linked Image] Now: [Linked Image] I can't feel the rough looking parts on the slip rings. There is no more wobble of the slip ring. not sure how much better I can get it.
 

wrcsixeight

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[Linked Image] Developed a better way to spin the alternator @ somewhat high rpm, in order to more precisely hone the slip rings. Not perfect, but I don't want to remove more material, just to get the remaining grooves out. I can see em, but not feel them.
 
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This thread is great. Hands-on making it happen. Nicely done. Creative thinking with the wire-brush/pulley interface and PWM controller. Took some thinking to rig all that into place. I'm wondering if they just didn't shim the commutator/armature properly, or was the brush holder bent? -m
 
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Originally Posted by wrcsixeight
No idea where the remanufacturing occurred. http://www.wilsonautoelectric.com/PartDetails/Index?partId=ba0d2bbc-44d3-4735-8b83-a567746add93 This was an O'reiley's sourced lifetime warranty replacement, and apparently was the last one they will give me. It seemed more robust, output wise, than its predecessors, until that brush could no longer contact the slip ring. The NEW Nippon Denso Alternator currently replacing it, is disappointing in output at hot idle speed. I was led to believe it would be superior at hot idle, but it is not. Made in Malaysia, via AZ. I've not tested it for absolute max output, yet. but hot idle speed when brand new could barely keep up with loads at night, the Wilson had an extra 20 amps at hot idle for battery charging. I've lowered brush holder and am truing up the slip rings, and gonna return the Wilson to duty once I give it some more spit and polish.
What do you mean the last one they will give you? As long as you aren't obviously abusing the warranties you can get it replaced repeatedly. Of course if you took it apart before trying to warranty it...
 

wrcsixeight

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I did not open it up until well after they said they had no record of me ever buying an alternator. Spent a good amount of time on the phone and they had me and my new and old phone numbers, and other parts I bought on file, but no Alternator. This lifetime warranty kept me from bothering to open it up and satisfy my curiosity, or look for units better inline with my demands. I had gotten no less than 6 alternators on it since 2004/5. This alternator just has one nut and the whole black plastic cover comes off though, revealing the rectifier and brush holder. It did not have paint or a sticker to indicate tampering. The slip rings were either set too low on the shaft, or the brush holder, if replaced with a new part, was not dimensioned correctly. I shortened the legs of the brush holder, and the base of it now resides on the machined flats containing the bearing, instead of a MM above it.
 

wrcsixeight

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Took this project out of the box again. Made some thicker copper straps spreading AC current from stator to the Diodes. [Linked Image] The 6mm + output ( magnetic) stud was loose, and took no effort to remove. The capacitor's ring terminal and where it resides at base of 6mm stud, is nicely distorted. [Linked Image] There was a huge amount of zinc oxide thermal grease between rectifier plate and Alternator body. The bottom of the rectifier plate is badly dimpled and far from flat. Thermal grease is no where near as good as flat metal mating metal in the thermal transfer department. This pic is one swipe of the rectifier on some worn 220 grit adhered to plate glass. The bottom of the rectifier plate also had the charcoal grey paint inbetween alternator body. further inhibiting the transfer of heat from Diodes to alternator casing. [Linked Image] Rock Auto wants 45$ for this part ( 2 needed) and it says 75 or 90 amps, while this alternator is rated and has produced 120 amps in th past [Linked Image] I ordered a new rc50 capacitor, as the ring terminal rotates freely, and I was occassionally getting alternator whine in my speakers with this alternator when it still worked. The alternator which replaced this one, performs badly when at hot idle, with about 35 amps max, but 300 more rpm and it can make 85 amps, and can make 109 amps at 1150 engine rpm, at least before it gets too hot, but it cannot make 120 amps at any rpm, and it is rated at 120 amps. I'm going to return the alternator I am refurbishing and then open up this replacement, see if it too can benefit from more copper/ less resistance and better thermal transfer.
 

wrcsixeight

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2,205
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I did not need to open the alternator casing to make thicker copper bussbars spreading the 3 phase AC among the Diodes(12 total), or to flatten the bottoms of the rectifier plates and alternator casing for better thermal transfer.

I did all I could to insure great electrical contact between bussbars and Diode pairs, and thermal transfer from rectifier plates to alternator casing, and to eliminate any steel fasteners from transferring the DC output to my ring terminal feed to battery. I used some arctic silver thermal grease to reattach rectifier plates to the casing,buttoned everything up, and spun the rotor, only to hear something was lightly rubbing on the spinning rotor.

After the curse fest ended, I opened the alternator casing and removed the stator, and found one of the 6 wires, going to the 3 ring terminals was loose and able to hit the rotor. It had come unstuck when I gently pried the ring terminals back, in order to get the thicker copper busbars in place.

It was also obvious that this had occurred once before, before my ownership of it, and was glued back by whomever rebuilt the alternator pre 2015. The one wire was scratched from previous to my ownership contact, and there was a blackened receptacle in the varnish where it originally rode.
I though the stator was shorted as it read 3.5 M ohms between leads and stator casing, but on any other range read open circuit, as it should. The auto range of my multimeter is automatically chosen when it is turned on

So I need to reattach this wire so it cannot touch the rotor, and also prevent stresses from 2 other stator leads from doing the same. The gouges in this wire occurred previous to my ownership. I only spun the rotor about 10 full revolutions, hearing the contact, and opening it up.
20200717_161221.jpg


Not sure how well the varnishes designed for electric motors act like glue, not that I have any, but the JB weld I do have, is supposedly di-electric(non conductive) and good to 550f and should bond to old varnish and fulfill my wishes. I've found a new stator for this alternator for 50$, but do not think it is necessary. I'm only into this repair for the 1.5mm thick copper bars I bought and the new rc-50 capacitor which was ~8.50 delivered.

I've learned a lot so far doing this.



Ideally the external fan next to dual V belt pulley, would not have much space between its blades and the front casing of the alternator, for maximum air movement through the alternator. My fan wobbles slightly and at its closest has a 5/32 inch gap, far from ideal.

I am not sure whether I am going to address that, at this time. I do ask alternators for everything they can make, often, so more efficient airflow through it is certainly desirable, but I don't really know how much more would move through it with less clearance, or how easy that lesser clearance would be to achieve, as I have not had to remove the pulley or fan at this point.

I want to see if it works properly first. it only takes me 10 minutes or so to R&R an alternator. If it works I might leave it or remove it address the fan issue.

I'd like to remove my useless AC compressor and put a second alternator in its place, which I will already have should my ministrations to this one prove successful. Making brackets to align it perfectly is something I am dreading though. My AC compressor has been a pulley only for 15 years on this Mopar LA-318 and nearly 100K miles. I expect its bearings could go all Murphy's law on me, and would much prefer to have a second , externally regulated alternator there instead. I already have a second adjustable voltage external regulator ready to control it and would wire the regulators to be either or, or both together at the flip of two rocker switches.

I am aware better, higher rated alternators exist. 6 phase hairpin wound models by Mechman make me drool, but I cannot justify that kind of expenditure.

I'd also rather have 2 120 amp alternators than one 240 amp one(400+$) and have to swap over all pulleys to a wide serpentine belt(?$$) , as dual V belts are only good for ~140 to 150 amps continuous, depending on how much wrapping of the pulley there is.
 
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25,789
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MA, Mittelfranken.de
Nice work! More and more of these rebuilds from the chain stores are just no good. I have much better luck with clean low mile used parts if I cant repair the one in the car for whatever reason (usually parts availability).
 

wrcsixeight

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2,205
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california
Thanks Trav.

I cleaned the magnet wire with a Q tip and rubbing alcohol, used zip ties to hold the loose stator wire where I wanted it, then some JBweld to hold it out of the way of the rotor and after it cured removed the zip ties.

I very much dislike using steel as a conductor in charging paths, so instead of the tall 10mm hex nut on the 6mm stud from rectifier plate, I stacked 4 4mm thick copper bars cut to size that rest on the rectifier, and pass current to my thick walled tinned ring terminal and thick cabling to my TPPL AGM group 31 battery.

20200720_175758.jpg
20200720_180228.jpg


I bypassed the In engine computer voltage regulator with a 10 Ohm 50 watt resistor oin between the original wiring to the field terminals, and use an adjustable voltage external voltage regulator to control the alternator output to achieve the voltage I want, for best battery charging, not MPG's.

To eliminate the steel nut and bolt which formerly passed field current to the one brush that is not grounded, I made a copper nut for the ring terminal for the field wire from voltage regulator. The other field terminal, with the steel nut, well that brush is now grounded under the end cap to alternator body where the capacitor mounts to it.

20200720_175849.jpg


I got it reinstalled in my engine bay, and this morning, with 84 of the 103Ah removed from my group 31 AGM battery, started my engine. The alternator does make its 120 amp rating at about 1300 rpm, and while I did not get it fully heatsoaked, measuring only 160F on the stator, At Idle speed it appears it can produce 10 more amps than it could before, and 20+ more amps than the replacement Nippondenso clone alternator could when hot at the same rpm.

So mission accomplished, for the price of the copper bars of which I have a lot left of, and a new capacitor I have a fully functioning alternator again that seems to be more heat tolerant than before.

The stacked copper bars where my ring terminal mates, in direct contact with the aluminum rectifier plate is an area of concern, I was not aware these two metals should not should not be in contact with each other. However there was a tiny thin copper bridge between the two rectifier plates before, that showed no sign of galvanic corrosion in my often salt air environment, so perhaps it is a non issue.

I now have a back up alternator too, but want to remove my useless AC compressor and replace it with the alternator, as 120 amps is not enough to bring my well depleted group 31 AGM battery to 14.7v instantly, and this battery laughs at such charging rates, when ambient temperatures are 80f or below.

I voided the warranty on the new Malaysian assembled NipponDenso clone alternator bought 7 months ago, to have a look under the tailcap.
20200720_222203.jpg

I see little that I could do to improve heat dissipation or reduce electrical resistance. I did not remove the brush holder, but I can hear the brushes riding on the slip rings when spinning the pulley by hand. I could not hear this with the other alternator and its polished slip rings, but perhaps could after a few thousand miles.
 
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