Anybody rebuild their own alternator?

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518
Location
Severna Park, MD
I recently replaced the alternator in my Saab with a Mexican rebuilt for $115 from RockAuto, and prior to that I always bought rebuilt alternators from my local parts store. From my own experience working at an auto parts store I know there is a huge markup on rebuilt parts. My Dodge Ram is approaching 90k miles and I'm thinking about doing some proactive maintenance in the near future, to include cooling system flush, t-stat, water pump, and serpentine belt. While I have the belt off I might as well pull the alternator too. I saw an online video of a guy rebuilding the Bosch alternator from a Dodge Ram and it looked ridiculously easy. Didn't find a rebuild kit for that alternator, but I found a source for the bearings. If I can find the voltage regulator maybe I'll try to rebuild it myself. Anybody here rebuild a Bosch alternator, or any alternator?
 
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15,630
Location
Santa Barbara, CA
They taught us how to do it when I went to school for auto repair, but it is not worth it anymore. As far as a "huge markup" on rebuilt parts, maybe in the aftermarket, but not at a dealer level. We have rebuilt alternators that retail for $350 with only a $40 profit built into the pricing.
 
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5,532
Location
Canada
I have found alternators can last a very long time, I would not assume one at only 90k needs a rebuild. But if it did, I would rebuild it myself, with some quality bearings, rather than take a chance on a cheap aftermarket rebuilt unit. It's not hard.
 
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2,412
Location
Seattle-ish, WA
What expat said. Last alternator I rebuilt this summer lasted 225k. My main concern is that "rebuilt" alternators from parts stores are often junk - incorrect parts, etc. and don't last. I'd rather hand the unit over to a local shop to do individually than replace it with one of unknown origin. I rebuilt the Denso alternator in a Lexus this past summer. I went to a an auto electric specialty store in nearby Tacoma, WA (Romaine Electric). I purchased the bearings and brushes that were totally unavailable online for $26. It took less than an hour to rebuild it. Unless you have output issues, I don't see a strong need to change the voltage regulator. They only wear items are generally brushes and bearings. This is the place I got parts from. The do mail order - give them a call. Honestly I'd get a rebuilt from a place like this over a place like Autozone, etc. http://www.romaineelectric.com/
 
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Joel_MD

Thread starter
Messages
518
Location
Severna Park, MD
Originally Posted By: bdcardinal
They taught us how to do it when I went to school for auto repair, but it is not worth it anymore. As far as a "huge markup" on rebuilt parts, maybe in the aftermarket, but not at a dealer level. We have rebuilt alternators that retail for $350 with only a $40 profit built into the pricing.
When I worked at a parts store in the early '90s a typical rebuilt alternator cost about $15 and we sold it for $45. It was about the same markup percentage for rebuilt water pumps. It was interesting to see how things were priced when I worked there. The store lost money on some types of motor oil, but little packages of things that hung on pegboard hooks (tire valve caps, screws, etc) cost ten cents and we sold them for 99 cents. At a dealer parts counter I'm guessing that Ford is selling to the dealer at a huge markup, and the dealer is marking it up a little more when they sell to the customer.
 

Joel_MD

Thread starter
Messages
518
Location
Severna Park, MD
Originally Posted By: Oro_O
What expat said. Last alternator I rebuilt this summer lasted 225k. My main concern is that "rebuilt" alternators from parts stores are often junk - incorrect parts, etc. and don't last. I'd rather hand the unit over to a local shop to do individually than replace it with one of unknown origin. I rebuilt the Denso alternator in a Lexus this past summer. I went to a an auto electric specialty store in nearby Tacoma, WA (Romaine Electric). I purchased the bearings and brushes that were totally unavailable online for $26. It took less than an hour to rebuild it. Unless you have output issues, I don't see a strong need to change the voltage regulator. They only wear items are generally brushes and bearings. This is the place I got parts from. The do mail order - give them a call. Honestly I'd get a rebuilt from a place like this over a place like Autozone, etc. http://www.romaineelectric.com/
On the Bosch alternators I believe the brushes and voltage regulator are a single component. At least that's how it is on the Bosch alternator on my Saab, which looks very similar to the one on the Dodge. That company Romaine Electric looks like the perfect place to get the parts. I know this alternator will likely last longer than 90k miles, but I like to replace parts when it's convenient for me, not when I'm on vacation with the family far from home.
 
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6,180
Location
Illinois
Most nowadays have the brush pack and regulator as a replaceable part on the exterior of the alternator. Last one I tried to rebuild was from a Ford Taurus. It had a bad bearing in it on the back side. Unfortunately the back cover has all the diode legs solder into it and it was very difficult to remover and I never was successful in getting them resolder back in well.
 
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36,531
Location
ME
I opened up a saturn alternator (CS series?) and changed the bearing. Super easy. IIRC the bearing was a 6203 and cost $2. An impact wrench helps with the "big nut" and an old serp belt used as a strap wrench gets enough grip on the pulley to keep it from spinning too. Despite (or thanks to) being a greasy mess the long male torx bolts holding the case halves together came out easy. There are youtube videos about clipping the diodes and changing them: If you can solder, you can do this, it seems. Pro tip, GM alternators at least seem to have different part numbers just depending on how the mounting ears point. You can make "one good out of two" if you get them in front of you. Good if you have a supply of junk parts.
 
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6,180
Location
Illinois
Another tip when replacing alternators is to always keep the original pulley. Many of Fords alternators were the same except for the pulley and it would cause problems if the new one had too small or too big of a pulley for that engine.
 
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1,769
Location
Toronto Canada
I can buy a rebuilt alternator for less than I can buy the parts necessary for a proper rebuild. They seem to work fine but I doubt they are as good as new. At the time I buy a rebuilt alternator, the vehicle only has a couple of years of life left so the rebuilt is good enough. The cheap rebuilds are good enough for me.
 
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7,430
Location
beaver land EH?
I used to rebuild Nippon Denso alternators (inspection, commutator check and clear the gap, look for uneven wear, etc.) and replace the brushes, etc. So long the bearings are fine and diodes are functioning properly (with regulator built in), I don't go beyond that. I also do minor rebuild with Mitsu alternators back then, same methodology applies.(with brand-new mitsu brushes). Nowadays, I don't do much of alternator rebuilding, citing that both the ND and/or Mitsu factory alternators will lead a very, very long and healthy service life so long as the load (fault) is not on the battery side. In other words: I turned around and focus my attention on the battery health instead. properly-functioning battery leads to low-wear, long service duration alternators (and reliability from factory OE units that some aftermarket units can't even compare). Q.
 
The alternator on my son's Hyundai Tiburon seized when sitting in the garage for a few weeks. Probably the brushes stuck on the slip rings? I would try to rebuild it, but I can't source any parts for it locally.
 

Joel_MD

Thread starter
Messages
518
Location
Severna Park, MD
Originally Posted By: OldSparks
The alternator on my son's Hyundai Tiburon seized when sitting in the garage for a few weeks. Probably the brushes stuck on the slip rings? I would try to rebuild it, but I can't source any parts for it locally.
These guys stock a lot of alternator parts; looks like they'll ship to Kanuckistan. wink
 
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36,531
Location
ME
Originally Posted By: OldSparks
The alternator on my son's Hyundai Tiburon seized when sitting in the garage for a few weeks. Probably the brushes stuck on the slip rings? I would try to rebuild it, but I can't source any parts for it locally.
I had a jeep at work do this after sitting for months. I eventually bought said jeep. I put a breaker bar on a socket on the "big nut" inside the pulley and busted whatever inside froze, loose. It squeaked for a while then quieted down and worked.
 
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9,105
Location
Houston, TX
This post got me to thinking about the alternator in my FX4 (which is heavy duty for the towing package it has). AAP has a lifetime warranty unit for $210 which I could reduce to a lower price with a code. At what price point is it worth to try and rebuild yourself? 50% less? 25%? Just curious what the thoughts are...
 
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7,485
Location
S California
With the Honda in my signature below I have been replacing the brushes every 100K miles so at just over 400K I'm still on the original alternator with 4 brush block changes.
 
Messages
18,201
Location
NH
Originally Posted By: 2010_FX4
This post got me to thinking about the alternator in my FX4 (which is heavy duty for the towing package it has). AAP has a lifetime warranty unit for $210 which I could reduce to a lower price with a code. At what price point is it worth to try and rebuild yourself? 50% less? 25%? Just curious what the thoughts are...
What's the core charge? Could get a reman and have your OEM one rebuilt. Then if the reman pops, swap in the rebuilt one, which ought to be "better". I'd base my decision off that.
 
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4,256
Location
Central Maryland
A tale of two cores... Due to a bad auto parts website application guide, I recently bought an import rear brake caliper with a $55 core charge for ~$125. They graciously exchanged it for the correct Dodge front brake caliper, which had a $30 core charge on a $44 price. Parts to rebuild the import caliper might be much more, but I'm thinking there's a lot more margin possible on the $70 delta than the $14.
 
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