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One Piece At A Time - - - redesigning the designs

One piece at a time

Why is it that in one car the heater core is a snap to replace, while others have a zillion screws and countless pieces that need to be removed? Or, the A/C compressor is buried so deep in the engine compartment that hours upon hours are spent just to get it out? I suppose it all comes down to how the car needed to be designed and the allowable space provided. But, all this digging around sure doesn’t make the mechanic’s job any simpler, or when it comes to giving an estimate to the customer.

What if, instead of engineers and designers making the decisions about how all those components are shoe horned into the car, they left it up to the mechanic to decide where they go? I would definitely change how some of these cars require the entire dash to be removed to gain access to the evaporator core. In fact, I would probably have an access panel behind the center section of the dash. You know, just remove the radio and the heater controls and unfasten some sort of door and there you are. I would move the evap core and heater core connections somewhere else besides wedged between the firewall and the engine. I’ve never liked having to “plank” across the engine bay and wrestle those fittings loose.

Oh, I’m sure it wouldn’t be practical to have mechanics design it. Besides, every mechanic who’s worked on cars for a few decades would have a few favorite choice parts they’d like to see used vs. some new unproven and yet to be tried out part. Although, the final appearance of the mechanic’s creation might look something like the Johnny Cash song, “One piece at a time”. You know an engine from one year, a radiator from another, perhaps a door handle and latch from something else, and an ignition switch from an entirely different decade.

It’s not just access to some of these parts that the engineer’s design seems to be more important than serviceability, it’s the way some these parts are fastened to the car, like door panels for example. One year they’ll use push clips and the very next year it’s hooks and screws. Or, the material they built “this” year’s door panel becomes so brittle after being out in the sun for a few years that by the time a window motor or switch needs replaced the whole thing snaps like a dry twig.

Just getting a serpentine belt off of some cars requires removing a motor mount or the use of some crazy half twisted and contorted tool to take the tension off the belt. It’s just insane how many variations in design there are. Seriously, they should consult the guys and gals in the service bay about some of this stuff first. Yea, I know, a lot of the design aspects of the modern car are done in a particular manner for quick installation at the factory. That might be great to get the car down the assembly line, but it doesn’t help a bit when it comes to service work. Oh, and I can’t leave out those hidden bolts and squirrelly double locking clips that can frustrate even the best mechanic out there.

Granted, back when we switched to the electric pumps in the fuel tank there were probably a whole lot of design issues that weren’t considered or perhaps were entirely overlooked. And, I’ll bet there was a stock pile of metal tanks already pressed out on those big machines. But, why didn’t anyone think of adding a trap door to ALL the different models instead of having to wrestle those cumbersome metal tanks from under the car? You mean to tell me no one could figure out how to add a trap door in the bed of a pickup truck either? Seriously…

These days, with all the electronics and computer systems you’d think design issues wouldn’t be nearly as complicated as they were before…. ‘fraid not! Now it’s not only the design, it’s the programming, the software, and configuration issues. I run across so many various models with modules that have become obsoleted from the manufacturers, and it’s just about impossible to find any good salvaged replacement parts, let alone, how some of these modules can’t even be used again if they were already programmed. Many times a customer will ask me, “Why did they design it that way?” I just shake my head and try my best to explain that things are the way they are because they are the way they are, basically… I don’t have a clue.

I seriously doubt any of the auto manufacturers would ever ask what the little old mechanic thinks of having to remove the entire front bumper assembly just to change a headlamp. We’re just supposed to do it and accept the fact the customer is going to question the cost of the repair, and probably spend a lot of time calling other shops just to make sure they are not getting cheated or over charged.

I suppose all these changes are job security for the mechanic. Who else would want a job where everything you previously learned is now useless information on the next model year you work on. This means the mechanic has to spend an enormous amount of time studying the latest systems and procedures just to be able to do what he did on a previous model.

Even though some things about the modern car are far superior to their predecessor, there is still room for some serviceability design improvements. Of course, you can forget about asking me what I think of their changes. It’s not like they can’t find me, I’m right where I’ve always been. Right here in the service bay doing what I’ve done for years, looking up the procedures, rolling my eyes at how many steps it takes to change a light bulb, and dealing with those changes.


For me, it’s back to work, tearing things apart and putting them back together and like always… one piece at a time.

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First, I love that song by Johnny Cash, One Piece at a time.


Like you, I have been shaking my head for years. Why designers do what they will always be a mystery. And the truth is, they will never listen to us, the people who actually have to fix what they design. But, I agree, to remove a front bumper to replace a $2.00 side marker seems just a bit extreme. And, we are left we having to explain to the customer, the labor charge.


Perhaps the amazing thing about all this is how talented most mechanics are at repairing cars in spite of how they are built.


Great insight Gonzo, great topic.

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Once I heard an engineer say why they make car so difficult to work on. He said they are built from the standpoint of assembly, so that they are built to keep assembly and part cost down. Repairing them is not a concern, at least not initially!

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Just about every day I wonder what were the engineers thinking while struggling to do something simple. Sometimes its simply my lack of experience with a certain model. A few minutes on Google saves me considerable time. Other times the reality is as it seems.

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