By on July 8, 2012

This article is the second in a series wherein—after thrashing manufacturers for doing their worst—I do a quasi de facto “equal time” summary of ten automotive mechanical technologies I believe are their best efforts, to date.

To review the guidelines I’m holding to in assembling this list: these are technologies that are pretty well universally accepted and are currently being used by the majority of auto manufacturers. They also have been popularized and proliferated during my automotive repair career. I’m covering them more-or-less in the order that they have achieved that status.


 The One-Piece Rear Main Seal:

Although it seems the European and Japanese manufacturers picked up on the value of using this technology from as far back as the late ‘60’s, if not earlier, it took the U.S. manufacturers a little longer to get with it. It wasn’t until the cycle for their earlier engine designs—sporting their two-pieced “rope-type” Crankshaft Rear Main Seals—had run their course, and new designs made their debut, that it could be said that they had now bought in to this technology.

Initially, the Yanks updated most of their older engine block designs by tossing the two-piece rope in favor of the two-piece neoprene seal countermeasure. While being an improvement over the rope, this upgrade still had its drawbacks: there were still some leakage and longevity issues, but the big bogey was with servicing it.

More often than not, to completely replace both halves, not only did the oil pan and rear crankshaft main bearing cap have to be removed, but usually the whole crankshaft, too—in order to access the half remaining in the block. Usually VERY DIFFICULT to do if the engine was installed in the vehicle!

With the one-piece, not only was oil leakage now reduced to nil—and for an extended time and mileage period, no less—the seal could easily be serviced during clutch replacement (back when many vehicles HAD clutches), or whenever the transmission was removed for repair. Highways, byways, and DRIVEWAYS across the United States of America all rejoiced in unison at this advancement! I doubt Oil Companies did, though.

So, how about that? A “one-piece” becoming the paradigm, and most desirable under ALL circumstances…

The Asian Gear-Reduction Starter:

Developed as a bulletproof-reliable solution for industrial and fleet vehicles in Japan, this design saw a rapid rise to popularity in Japanese passenger cars as far back as the late ‘60’s.

While the demands imposed by the rather small-displacement, lower-compression engines found in those vehicles didn’t really tax the abilities of this starter, they did allow for some incredibly long-term reliability records as a result. Other manufacturers took note.

Chrysler was among the first to develop their own gear-reduction unit, which was standard equipment on many of their cars at around the same time as the J-Units were being impressed into service. No one can forget the characteristic sound these Detroit-edition starters made. They did do a good job of spinning the high-compression engines prevalent during that period in U.S. auto manufacturing history—all comments about the sound they made while doing so, aside.

They worked so well because the actual motor section of the starter was not directly driving the pinion gear (which contacts the Flywheel Ring Gear) at a one-to-one ratio, as had been done for so many years previously. It rather drove the pinion via an internal reduction gear, allowing the motor to spin at a higher, more efficient RPM. This effect also allowed engineers to use a dimensionally smaller motor to accomplish what the larger, power-hungry direct-drive units of the past were able to.

The advantage of the Asian unit, however–besides having a motor of superior quality—was really in its solenoid design. Since the rest of the starter already had the potential for an absolutely INCREDIBLE service life, the only area of wear-concern was the high-amp contact posts within the solenoid, which bridged power to the motor.

To solve this problem without necessitating a more expensive solenoid replacement (as other manufacturers had), the engineers of these units made it easily possible to replace just the contact posts by themselves. Think of it: at the point where a conventional starter would be considered “failed”, and in need of overhaul, these starters would just need the contact posts replaced, and they’d be ready for the “next life”!

Full-Flow Engine Oil Filtration:

Oiling system and oil filter technology has continued to advance in the forward direction for many years since the days of “splash-oiling”, internal roller and needle bearing crankshafts, and filterless systems using non-detergent motor oil.

Even when us automobile owners and techs were “blessed” with the advent of the “spin-on” oil filter, incorporated into engines from the early-mid ‘60’s, we still were not completely out of the “dark ages” yet. Oiling systems were generally not designed to filter all, or even MOST of the oil being pumped throughout the engine at a given time. As a result, engine life generally was maxxed at about 150,000 miles, under the best of circumstances.

On the plus side, at least THOSE engines were completely rebuildable, so they could do another 150K with no problem, if the build was done correctly.

When Full-Flow oiling systems debuted in some European and Japanese passenger cars, before long it became understood that engine life had effectively been doubled, in some cases, just from the implementation of this ONE technology.

Now, virtually all passenger car engines employ full-flow filtration systems, and many vehicles have the capability of going 300,000 miles on the same engine, without need for a “rebuild break”. I might add that modern oil technology itself has also contributed to this fact. This is all a very fortunate thing for car owners, as many of these same engines are now effectively unrebuildable!

Phil Coconis is the owner of a West Coast independent auto repair shop.


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17 Comments on “Phil’s Podium Of The Automotive Pure: Ten Trick Technologies That Changed the Automotive Maintenance & Repair Scene — Part Two...”

  • avatar
    Felis Concolor

    I remember the wave of aftermarket Hitachi high-torque starters fitted to domestic nose pieces; their big selling point was the smaller size of the housing, allowing for improved exhaust header clearance and added room for heat shielding to improve component longevity.

  • avatar

    Your last paragraph opens an interestiong question. What are these engines that cannot be rebuild and whst makes them unrebuildable?
    I’ll start with one: The (non US) Ford/Jaguar-Land-Rover/PSA V6 Diesel. The only service items you can buy are a short block, heads, or a complete engine.

    Thanks for an interesting read, Phil.

    • 0 avatar
      Phil Coconis

      Howabout the infamous NORTHSTAR V-8…or any other engine employing Torque-to-Yeild internal fastener technology. Anything relying on align-boring will have to be align-bored again. We’re only talking theory here, because replacement bearings would have to be available in oversize to compensate for the fresh bore. They aren’t available, and would be cost-prohibitive to use if they were!

  • avatar

    A new automatic transmission costs about the same as a new long block – and they are getting ever more expensive as the number of gears goes up – so why don’t they have effective full flow filtration? The metal screen/magnet in the pan is a sorry joke. I’ve installed a partial flow real oil filter in my coolant line but I’d like a real full flow filter in every auto trans.

    One more question – why are their 200 different oil filters? There should be three – one for small engines, one for medium, and one for large. I would make it a federal law!

    • 0 avatar

      Ideally, your transmission is a sealed unit: nothing gets in that you don’t put in. Your engine on the other hand is constantly exposed to contaminants from the outside air, fuel, and combustion byproducts. So adding filtration to the transmission wouldn’t extend the life of it because contamination isn’t what wears in the transmission. Your enemy there is heat.

      • 0 avatar

        Benders, sorry, but I couldn’t disagree more. The #1 reason for an engine oil filter is to remove metallic wear particles from the engine oil, not contaminants from the outside air (air filter takes care of most of those), or fuel and combustion byproducts (oil filter doesn’t remove most of those – that’s one of the reasons why you have to change your oil).

        Have you ever dropped an auto trans pan yourself? I have, numerous times. There’s usually half a teaspoon full of steel particles stuck on the magnet. These particles are way too small to be stopped by your typical steel mesh transmission “filter”.

    • 0 avatar

      My favorite pet peeves regarding AT transmission are those which no longer have drain plug and an inaccessible pan – by which I mean the front suspension gets in the way of dropping the pan.

      • 0 avatar

        Actually, the number one job of an engine oil filtration system is to remove oil impurities that are forced out of suspension by the extreme heating and cooling cycles the oil goes through while doing its job. In a broken-in and properly operating engine there should be very little if any at all introduction of metal into the oil.

  • avatar

    Hey man…you should be numbering these…I think this is items 3-6, right?
    My ’78 250 chevy has a two piece rubber don’t have to drop the crank to replace the rear main seal…you get a banana shaped tool with the replacement seal, and you use it to push the old seal out, and the new seal in. I still prefer the one piece seals…especially the kind that have a bolt on retainer, so you can unbolt the whole thing and replace the seal on you workbench.

    • 0 avatar
      Phil Coconis


      Yeah, those tools might work on a NEWLY INSTALLED seal, if no sealant/adhesive was used in its installation. What would be the point of that, though? But on an original seal on an engine approaching 100K miles?! Surely, you jest! And if you really try to get physical with the removal (literally) scratch one crankshaft!

  • avatar

    For the last point it’s probably engineering adapting to the needs of the industry. Older engines could be rebuilt because they had to be at the 80-150 K mark. Because newer ones should outlive the body of the car they are installed in, why bother.

  • avatar

    Actually it’s adapting to the CAFE standards. Older engines were made with great big hunks of cast iron, and could be re-bored 3 – 4 times. Modern engines have very thin walls to make them lighter for better fuel economy. Some modern engines can’t be bored out even once.

  • avatar

    Waxes for the paint have also improved thanks to the onward march of technology that may some day put man and their wimmenfolk and serving wenches wandering through the galaxy, exploring and interacting with various alien folks.

  • avatar

    I would say the need for constant improvement in engine tech. Is driven by the motor industry need be competitive and by evolving lifestyle needs of the consumer.
    As a customer I want economy, reliability, longer service intervals, more power and… Yes, as a customer, I am right!

  • avatar

    Phil, what are those factors that make modern engines unrebuildable? I know that rebuilding shops have had to upgrade their equipment to keep up with things.

    • 0 avatar

      The point where shops could say in all honesty and profitablity “it would be alot cheaper to buy a new engine vs. rebuilding this one”

    • 0 avatar

      Is it the expense of the local mechanic’s labor, or is there a technical reason that makes an engine ‘unrebuildable’? (Use a Honda V6 for sake of argument.)

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