# Alternator question **URL:** \ **Category:** Factual Questions\ **Created:** [February 24, 2010, 9:33pm UTC](https://boards.straightdope.com/t/alternator-question/530316 "2010-02-24T21:33:25Z")\ **Posts on this page:** 3\ **Page:** 2
**Author:** ![Gary\_T](https://avatars.discourse-cdn.com/v4/letter/g/3ec8ea/32.png) [@Gary\_T](https://boards.straightdope.com/u/Gary_T)\ **Post date:** [February 26, 2010, 12:20am UTC](https://boards.straightdope.com/t/alternator-question/530316/21 "2010-02-26T00:20:40Z")
> [@mazinger\_z](#): > > really? Then what am I paying for? I don’t understand what you’re asking about here. Are you thinking a core is something you get rather than something you give? (See below.) > [@](#): > > Is there any real difference then in a rebuilt versus a new alternator? In a new one, every single piece is new. In a rebuilt one, normal wear items are replaced (e.g. brushes and bearings), some parts may be reconditioned (e.g. commutator slip rings), parts that seldom if ever fail are re-used (e.g. case, stator, rotor). New alternators are certainly – and rightly – perceived as better than poor quality rebuilds, but I question if there’s much practical difference between new and high quality rebuilds. I have a very low failure rate with high quality rebuilds. > [@](#): > > What about parts stores? Every dude around here where I live says to go to Napa, but I like O’Reilly’s lifetime warranty. Pep Boys also has a new part, but no price listed, so I guess that’s another thing to ask about, like if a core is included. A core is your old part, turned in for credit when buying a rebuilt part. The core is then sent to the rebuilding plant to eventually become a rebuilt unit for someone else to buy later. [ETA: A core is like an exchange, turn in your old one plus some money and get a refurbished one.] New parts are sold without expecting a core from you\*, as the manufacturer of the new part is not rebuilding anything. As far as parts stores, I haven’t dealt with NAPA for years (not one close by), but always thought they had decent quality. I’ve been dealing with Carquest and O’Reilly and quite satisfied with their quality. I would be leary of places like Pep Boys and Autozone, as my perception is that they target the do-it-yourselfer who is more concerned with low price than with high quality. Note, however, that NAPA, Carquest, and O’Reilly want to compete with these places and so offer lesser-quality lines in addition to their high-quality lines. Stick with their top-grade stuff and you should be fine. Buy anyone’s budget-grade stuff and there’s a noticeably higher risk of getting a faulty part. * * * \*I have heard of some new items requiring a core to be turned in, but these are specialized cases. ---
**Author:** ![ralph124c](https://avatars.discourse-cdn.com/v4/letter/r/8797f3/32.png) [@ralph124c](https://boards.straightdope.com/u/ralph124c)\ **Post date:** [February 26, 2010, 4:51pm UTC](https://boards.straightdope.com/t/alternator-question/530316/22 "2010-02-26T16:51:07Z")
I mean, back when I drove Chevies, a new Delco alternator was about $50.00-$100.00 (max.) Plus, back when engine compartments were wide open, anybody with a set of wrenches and a crowbar could change one out in an hour or less. the absolute worst I heard was an alternator dor a M-B S500-$1200.00!:eek: ---
**Author:** ![mazinger\_z](https://avatars.discourse-cdn.com/v4/letter/m/5f9b8f/32.png) [@mazinger\_z](https://boards.straightdope.com/u/mazinger_z)\ **Post date:** [February 26, 2010, 10:29pm UTC](https://boards.straightdope.com/t/alternator-question/530316/23 "2010-02-26T22:29:54Z")
> [@ralph124c](#): > > I mean, back when I drove Chevies, a new Delco alternator was about $50.00-$100.00 (max.) Plus, back when engine compartments were wide open, anybody with a set of wrenches and a crowbar could change one out in an hour or less. > the absolute worst I heard was an alternator dor a M-B S500-$1200.00!:eek: Wow, I know what not to get next. I wonder what the alternators look like on an 07 BMW 5 series (diesel, preferably). Anyway, thanks to everyone for their helpful advice. I’m not looking forward to busting some knuckles wrenching this thing out this weekend. [Previous page](https://boards.straightdope.com/t/alternator-question/530316.md?page=1)