Good comment about spark plugs @oldbodyman . For my Corolla I change the spark plugs every two years, I’ve always used the same NGK part number that came w/the car new. The car is 20 years old so the parts places usually don’t stock that part number, but will order it for me. It usually arrives in a couple days from their warehouse. Around $2 per plug.
Our 2003 Toyota 4runner has remote locks. My wife drives the car most of the time and a couple of years back was having her key fob work intermittently. I traded key fobs with her and all was well until a couple of weeks ago where the fob I traded with her didn’t work reliably. I went to WalMart, found a two pack with the correct batteries for about $5. When I opened up the fob, one fob had a Panasonic battery and the other one had an Energizer battery. We had never opened the cases before. Apparently, Toyota has different suppliers for even something as simple as the key fob batteries. The fobs now contain aftermarket Ray-O-Vac batteries.
It’s common for manufacturers to have multiple suppliers for parts, especially for non-proprietary parts like batteries, tires, and bulbs. These are typically controlled with “specification control drawings”, where the request for bid will specify the physical and performance requirements for the part and Request For Quotes will be sent to multiple qualified suppliers. The control drawings’ details for common, readily available items like batteries will often be very basic, defining only what’s necessary. Often, the design drawing will list the part manufacturer’s standard part number. Parts will be ordered to the vehicle manufacturer’s drawing in order to prevent parts manufacturers changes from catching the vehicle manufacturer by surprise, but the documentation will cross-reference to the part manufacturer’s part number and revision.
In some cases, where the part is only produced by a specific manufacturer, or where the part has endure qualification testing, the procurement will be controlled with a “source control drawing”. “Source control drawings” can, and often do, list more than one supplier. Companies will often attempt to qualify more than one supplier for even a qualification tested part.
As a matter of fact, in something like a key FOB, the manufacturer of the system will probably control things like the battery in their drawings, and the vehicle manufacturer might even refer in their drawings to the system manufacturer’s details, controlling only what’s necessary to ensure successful and consistent interface.
It can be complicated, but in reality these control systems, known as “configuration control systems”, are developed software readily available. They’ll control the configuration of the design, the manufactured product, the inventory, the supplier base, work in-process, and much, much more.
@thesamemountainbike, the part that they couldn’t seem to explain and that I still don’t get is that according to them that .0025 deviation is shown on the engineering drawings. The ensuing 3 sets of main bearings that followed were also dimensionally off like the first set but were nearly in spec according to the mechanical drawings.
After 4 sets, I threw in the towel on the Federal Moguls and ordered a set of Clevites on-line. The Clevites were almost dead on in every dimension with any variances being less than .0002 of an inch and that amount is irrelevant. That .0025 variation still bugs me to this day; mainly because I always like to know the why behind something not being right.
If someone has a Ford with prematurely low oil pressure then maybe the yardstick method of parts production is the cause.
Wow; tossing hookers your way? That “benefit” can come with its own set of proprietary problems…
BD,very possible-Kevin
@ Triedaq,do you know who made the diesel engines for the Checkers? was it Continetal?last time I was there they had a couple diesel Checkers for use on the grounds at the “National Radio observatory” at Green Bank,WVa-Kevin
When the last Crown Vic bites the dust, maybe some entrepreneur will rejuvenate the Checker cab. I don’t see a replace save a truck based SUV. Last month we took a cab loaded with 5 people and luggage, and lots of it hot foot from the airport to the hotel, 30 miles away, at 70 mph in very good comfort. Any, fwd sedans out there that could do that hour after hour. Doubt it. Some car based SUVs but the maintenance would be much more and the fairs would show it. Bet Nissan steps in with a van on a truck chassis.
OEM spark plugs is probably my #1 recommendation.
OEM spark plugs are my #1 NON-RECOMMENDED part. The plugs are made for them by one of the leading plug manufacturers (or two). In fact owners manuals usually have the spark plug manufacturer and number.
My 4runner came from the factory with Denso plugs on one bank and NGK on the other bank. As long as you stick with one of the OEM manufacturers you’ll be fine. NAPA was probably selling Auto-lite or Champion as their NAPA plug.
Again, I want to point out that the OEM’s don’t use cheap tires. They use tires that have good fuel economy and that means they don’t wear well. If the only thing you care about is tire wear, you’re not looking at the whole picture.
Right OK4450, It can bring its own set of problems, especially when government money is involved.
I have to admit, though, that I could write a book about what was going on in the '70s and '80s. I’ve worked for two different DOD contractors that supplied the DCAS reps with full time (on the payroll) “girlfriends”, and both of the reps were married, and I know of one VP of procurement for a major DOD contractor that was supplied a Jaguar sportscar by a supplier. Those were eye-opening times for me.
@kmccune–I have never seen a Checker with a diesel engine. However Continental stopped supplying gasoline engines for Checker in the 1960s, so Checker switched to Chevrolet engines. I would doubt that the Checker diesels came from Continental. This is a wild guess–Checker could have used the Perkins diesel engine. I say this because in the late 1950s, some cab companies were testing these engines. In my east central Indiana town, the only cab company was running a 1959 Plymouth with a Perkins diesel engine.
Regarding the original post, I’ve seen aftermarket parts that were far superior to OEM at half the price, particularly for brakes. I think it depends on the OE part. Some cars use better parts than others. I buy the basic Sylvania halogen headlight bulbs at Wal Mart and they work perfectly. You just have to be careful not to touch the glass bulb during installation.
"the part that they couldn’t seem to explain and that I still don’t get is that according to them that .0025 deviation is shown on the engineering drawings. The ensuing 3 sets of main bearings that followed were also dimensionally off like the first set but were nearly in spec according to the mechanical drawings.
After 4 sets, I threw in the towel on the Federal Moguls and ordered a set of Clevites on-line. The Clevites were almost dead on in every dimension with any variances being less than .0002 of an inch and that amount is irrelevant. That .0025 variation still bugs me to this day; mainly because
I always like to know the why behind something not being right."
I can come up with literally a half dozen plausible reasons why this could happen. As has been said, knowledge is nothing more than a collection of bad experiences you can draw upon 
Imagine this scenario-
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Design engineering releases new design, all prints at Rev A. At this point the bearing specification is very tight at .2 thou-
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Component spec sheet lists approved vendors able to meet the restrictive specification.
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Some time passes and the supply chain is constantly under pressure to reduce costs. The bearings come into focus as a way to reduce materials cost. Lower cost usually translates into something lost, like tolerance margin in production volumes.
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Under pressure, manufacuring engineering revises the prints to increase the tolerance range and adds the lower cost vendors to the approved vendors list. Everyone is sent the updated prints, including the incumbent vendors. But they do nothing, as they have already designed and deployed their solution and it meets the looser specs.
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To compensate for the looser specifications and still meet the final assembly tolerance, they employ something like “binning” or “shimming” to make the less accurate parts workable in production.
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Subsequently, OK4450 has a bad bearing so he orders one, unknowingly supplied from a lower cost vendor producing parts to Rev B. It meets rev B of the component spec sheet but no one has communicated the revised assembly requirement in order to use the looser toleranced parts. In fact, they may not have even thought about the fact that the repair guy might not have a supply of parts on hand to accomplish the binning operation to match up parts to meet the upper level spec.
Anyway, I’ve seen this kind of thing play out before.
I guarantee you that if I had the parts in hand and was able to tour the company I could determine the root cause and how to correct it… IF the senior management wanted me to. But all I can do from here is say that something has apparently gone wrong.
With the comments being in a respectful tone, my point about those bearings is that they’re made to the spec provided by FOMOCO and those engineering drawings show an “allowable deviation of .0025”. The sets of bearings I got (other than one dimension) were all within the “allowable deviation”. By the paperwork the bearings are acceptable.
It’s often stated on this forum that cars are manufactured to tighter tolerances now as compared to the old days and that’s a premise I disagree with. Not when critical engine components are manufactured under a stated spec like the above and there is simply no way on Earth that two mated bearing shells can have different thicknesses and reach the proper oil clearance on that journal.
I’m going through an issue with an engine build right now that will likely cause me to never use or trust Plastigage again; and that product is made by the same company that makes the above bearings. Different story I won’t get into right now and will just say that the wax lies; badly… 
Anyhoo, regarding OEM and aftermarket parts I might add that a now closed massive parts manufacturing facility that was around for many decades in OK City turned out reman engines, transmissions, and individual components. This was a Ford authorized facility owned by a long time Ford dealer who was basically an institution in the Ford world in OK. He was nationwide.
Those “Ford reman” engines or transmissions one might get from a Ford dealer? The same engines were provided to various parts houses across the country with the same method applied to all of the smaller unit parts.
They even remanned GM engines which were supplied to both GM dealers and the aftermarket. This struck me as odd considering the heavy Ford involvement and Ford oval on the building.
So if someone recommended that a reman part gotten from the dealer is better than the part supplied by the local parts house around the corner that is not necessarily true. They all came out of the same building and I even knew personally 2 guys who worked there.
LOL, OK4450, I suspect this is one debate that will never end in our opinions being in congruence. We come from different life experiences.
I will say openly that while we’ll never agree on this issue, it in no way diminishes the respect I have for you. You still remain one of the few people with whom I’d leave my car with complete confidence.
As regards the claim that the term “remanufactured” means “better than the original”, the poster who made that claim is the first I’ve ever heard make it in all my years on the Earth. IMHO that is simply a misunderstanding of the term.
In my experience, even “improved” doesn’t mean it’s better than the original… it only means the manufacturer has in some way reduced hos cost to manufacture. It often means a cheap plastic part where a metal part used to be.
@thesamemountainbike, I still respect your opinions no matter how much they may vary from mine.
I’m fully aware that a +/- tolerance on production line items will never be dead on 0. I do some work on the lathe and mill and getting to .001 is not easy and also time consuming. I balance Harley flywheels on the lathe and those must be trued to .001 maximum or risk engine vibration at the least or engine destruction at the worst.
In regards to those bearings though, there is no physical way they will ever work properly and it stunned me to be told that they were providing those same bearings en masse to FOMOCO.
As I told the guy in their technical department; “Well, those guys on the assembly line may throw them together like that but I cannot in good conscience put something together that I know is flawed from the start”.
I’m also in full agreement with you on your comments about phrases such as remanufactured. While now defunct, there used to a large engine remanufacturing facility in OK City and they even opened up a sales branch not too far from me.
I had the misfortune of installing a few of their engines and nothing but trouble. One Chevy was blowing through 2 quarts of oil per day with very little driving. It was finally discovered that someone had omitted the oil control rings on all 8 cylinders.
Another had a slightly rough idle that I traced down to 2 weak valve springs; one on each bank. So much for “remanufactured long blocks”…
A VW engine reman facility in Tulsa shipped out 75 remanufactured engines to an OK City retailer and 74 of them came back due to early deaths. Again, I had the misfortune of being involved with one of the 74 faulty ones when it went belly-up inside of 500 miles and traceable to a warped cylinder head sucking air. The word “remanufactured” did not appear to mean much here either.
You apparently do not care about any input I have on the topic but I will pose this to the group anyway- why not turn this around and look at it from this perspective: if there is no way those parts can possibly meet the final assembly tolerance and would cause exceedingly low oil pressure if they were used, how do you suppose they are making thousands and thousands of those engines without some type of public outcry appearing on every serious car forum about lousy oil pressure on those ford engines? The answer would seem that somehow they ARE acceptable but nobody in this small population knows the real reason…however, I would venture to say that with what’s at stake, it’s unlikely that ford just cheaped out on the tolerancing of the bearing.
TT, the bottom line is that without a visit to the manufacturing facility with the part(s) in hand, and perhaps a visit to the engine manufacturer as well, it’s impossible to even guess what might be going on with OK’s parts. Or how thousands of engines could be being manufactured without rampant catastrophic failures. I used to get great satisfaction in solving these type of problems, but your question is unanswerable without the proper investigation. .
For reasons of convenience and price, I only go to a dealer for OEM parts when there is no aftermarket part available. So far, so good.