I read that the Japanese bearings (such as Koyo) are appreciably better than the Chinese ones. I feel inclined to Keep my original Toyota core and have the Starter/ Alternator Shop rebuild it with Japanese bearings (and keep it as a spare)…what are your thoughts (could they put in cheap bearings ?)
I don’t know why you didn’t return the core?
By the time you pay an electrical shop to rebuild the alternator, you’ll have more money in that than purchasing another rebuilt alternator.
These shops don’t do this for free.
You only use electrical shops to rebuild components that are very rare or very expensive.
Tester
O['reilly price for Chinese Alternator (in car now)is $180 with core…The rebuild place is $120 +$35 core ($155) with (better? bearings) just thinking that the Japanese parts are more reliable…Mike
Does the rebuild shop spec out the bearings and electrical components?
Tester
Have some fun. Take that puppy apart yourself, pull the bearings and buy Timken replacements and new brushes.
So you’re worried about the $25.00 price difference?
You should focus on the more important systems on your vehicle.
Something like? ahhhhh?
When was the last time the transmission fluid was serviced?
Tester
No…having Japanese parts…the trans fluid was changed 18 months ago with the frame/cross member impeding the pan removal lots of long and short 10mm wrenches …How’s the music…just listened to "Aftermath "- one of my fav along with “Supersession”…Mike
If this is what you want to do, than do it. It may not be cost effective, but hey, I’ve done things that weren’t cost effective too. I like Insightful’s idea; get an arbor press and some micrometers, open the thing up, measure the bearing assemblies, order some replacements from Timken, and give it a shot. Lateral and axial (thrust) loads and speed are really pretty low as bearing specs go, so there should be some standard bearings in the Timken catalog. See if you can find some “seating sticks” on the internet to reseat the cummutator brushes while you’re at it. The project might be fun. It’ll definitely be educational.
It’s water under the bridge now but why not just buy a new alternator instead of a rebuilt one? I just checked, and my wholesale price for a new alternator for your car is $12 more than a rebuilt one. That way you get a completely new unit.
Are you sure the original alternator on your car is Japanese. I would first make sure.
With all the recalls, we now realize that different manufacturers. use the same part supplier for their parts. I have a Mazda where the engine is from Ford (part owner of Mazda at the time) and the transmission is from Toyota.
Be careful…
The first sign of a natural-born engineer is spending $249 and an entire weekend repairing something that can be replaced for $29.95.
The second sign is always wanting to improve something… no matter how good the manufacturer made it.
If everyone around you thinks you’re eccentric because you spend too much time peering into small cavities with measuring tools in your hands and technical books open before you, well, the only thing I can say is that there’s no cure. Sorry. {
Toyota sells the parts, take it apart and do it yourself.
Toyota sells the alternator parts? Cool. And surprising.
I’m not an engineer, natural born or otherwise, but mountainbike’s comments apply to me. I’ll spend an entire Saturday evening on the lathe making something I could go buy for 10 bucks or redoing something that is not a problem simply because I wonder WTH were they thinking when they did this…
Not long ago I made a guitar pickup from scratch by using pieces of a CD case, worn out roller bearings, heat shrink, candle wax, and a lot of human hair thickness copper wire that I unrolled from some disassembled fuel pump relays and rewound on my own homemade bobbins.
Like Mallory on Mt. Everest I guess; no reason to do this other than “it’s there” and have a one-off… 
I prefer the rebuilt alternators, starters, etc to the after market “new” parts available at all the McParts stores. The failure rate of the after market new parts was considerably greater than that of quality rebuilds for me. From axles to water pumps the chinese knock offs gave me a lot of grief. But the Chinese bearings seem acceptable. Of course you likely get a Chi-Com bearing regardless of what brand name is on the box.
I think some here have “The Knack”
While I’ve only had two alternators fail, I had good luck taking them to generator shops and having them re-built. On my Saturn it was a bugger because the alternator wasn’t easy to get at, and on the Corsica it cost $100 and worked perfectly thereafter. The guy that did the alternator on the Corsica said they have some kind of a chip in them and if you just grab another alternator from NAPA, the chip might not match and it could cause problems. For the price, having him re-build it was worth the savings in aggravation.
I haven’t replaced an alternator in almost 30 years. They seem to be built a lot more reliable then they once were. Even my 98 Pathfinder with close to 500k miles had the original alternator.
I’ve rebuild a couple alternators from the 70’s vehicles. The last alternator I had to replace was on my 84 GMC S-1[5. I looked at getting the parts to rebuild it…but the parts were as much as a already rebuilt alternator.
I had to replace my alternator at about 200,000 miles. And I ended up with a spare.
My alternator began making a whirring sound (a friend said my car sounded like a spaceship). I went on the internet Thursday and ordered a new one “overnight delivery”. It was due to be delivered on Friday, I figured I’d put it in over the weekend. Friday on my way to work, my light came on. I was 25 miles from home (I commuted 31 miles each way) and knew I was screwed. So I stopped at the nearest shop and had one put in. When I got home that night, the one I’d ordered was on my doorstep. Rather than return it, I just stuck it on my inventory shelf in the garage, where it still sits.
If the Japanese bearings are so good, why did yours fail at only 69K miles? I will say that Nippondenso makes a pretty good alternator though. On my old car, the alternator failed at 210K, and when I got it replaced, the parts guy said “We don’t sell very many of these–they rarely fail.” This is a far cry from my first few cars where I replaced at least one alternator each at well under 100K miles.