Of course cheap design is the reason why I will never purchase another GM car, and over the years I know I have discourage at least a half dozen friends from buying one as well - and I don't miss an opportunity to tell anyone who will listen that my Blazer came apart in less than 60k, whereas my Jeep and Falcon still run fine and are both over 300K miles. So lost sales I am hoping more than overcomes the few cents/part saved.
I worked as a gearbox engineer for a Tier one supplier to GM, Chrysler, and Ford among others. In my professional opinion this had everything to do with money. That plug is there because it cost less than having a dipstick. First, you have part proliferation. A dipstick system includes a dipstick tube, a screw or clip to hold it up, a dipstick, and a grommet or o-ring at the bottom. That's four part numbers. The plug is one. You also have to have a bulge in the aluminum case to accomodate the diptstick. Somebody somewhere calculated that by eliminating the dipstick boss from the trans housing you saved 14 grams of aluminum. You also eliminated a core from the mold tool making the tooling for the housing a little cheaper and/or you eliminated the machining op to bore that hole. Sure you added some cost by adding that threaded hold but probably it's the same size as another hole allowing the use of an existing tool on a machining center. It's still probably a few coins ahead moneywise compared to having a dipstick assy. It all sounds a little crazy from the outside but I worked on this stuff. We'd do crazy things like that to save a quarter. When you make 300,000 of something a year it adds up.
As for being difficult for the consumer or shop to work on, I don't think GM gives a crap. They know that most customers (engineers such as myself and the other technical people reading this being and exception) really don't care if it's easy to service and maintain. GM knows that most people care more about the bluetooth capability or the compartment for sunglasses than they do about servicability.
Some people in the industry took this concept to extremes to save money. I remember a discussion about welding the gearbox halves together. The idea was it would save the money spent on case bolts and silicone gasket maker and the machined surface finish for the gasket maker. You could also weld with a robot rather than having a union employee start the bolts for the nut-runner.
How would you service it? You can't-and that was part of the idea. If there was a problem you would just sell a whole gearbox instead of a bearing or other part. This would increase the number or gearboxes sold and save money associated with carrying service parts, service manuals, etc. Ultimately this idea was deemed a little too extreme and scrapped. I was glad to hear it. But my point is that these kinds of extremes are considered in the interest of profit.
I also agree with ASmith. Eliminating the dipstick eliminates trouble for them. They don't have to worry about trivial warranty claims where the customer takes the new car back to the dealer the next day because the trans fluid is 'low' because they checked it cold or other similar things. The same goes for gauges. Newer cars runs hot. If you put numbers on the gauges (GM usually does, Ford usually doesn't) then you'll have a person taking their 2013 car in for a warranty claim because it runs at 200F. That was too hot for your '62 impala but for your 2013 Impala it probably isn't. Having a numberless temp gauge, or no temp gauge, eliminates that.
I get just as angry as anyone about stupid designs that prevent, or at the very least, make normal maintenance more difficult, but I do not think it is a conspiracy by the various car companies. Sometimes "GOOD IDEAS" are fraught with unintended or unforeseen consequences. I would be willing to wager that not one engineer/designer reading these posts has not had a mistake or two the someone down the line has blasted as stupid. Early in my career, my first foreman told me, " The only guy who never makes a mistake, is the guy who never does anything, but if you keep making the same mistakes, you will be looking for a new job."
In short, all I know is that with very few exceptions, my new cars/trucks are better than the ones they replaced. I get better mileage and more consistant service. I have never had any vehicle that could accelerate like my 71 Buick Skylark, nor ride as smooth on the highway as my 67 Olds Delmont 88, but both of those vehcles were finished well before 100,000 miles, but I have not had a vehicle since that hasn't crossed that threshold.
Larry M. said, "I explained the facts of life--expensive mechanics don't change oil or fix flats; high school dropouts do."
Please clarify that statement being applied only to the quickie lube & service places. Professional shops and fleet service specialists do a lot of oil changes and tire patching - only a fool turns down easy money and any company not willing to pay for professional level "service" usually isn't in business very long and at best they're not very profitable.
I trust the "lifetime" tranny fluid as much as the "lifetime" tie rod ends that never seem to last more than a year or two ... unless one is smart enough to put a zerk in them just like the old ones that lasted a long, long time as long as they got a little grease every so often. Problem is, the automotive industry consistently gets away with nonsense that no other industry could ever survive.
Well, my dipstick clearly shows both the COLD and HOT zones, aided by small holes that help a lot in showing where is the edge of the wetted zone in low light... Also the Owner's manual shows a drawing of the dipstick end which is so clear I can hardly imagine a dumb enough person unable to understand it (pardon me, I was forgetting the Monkey-type of individual!
Now, on the "fill for life" recommendation, it is as vague as to be useless, as how hard is hard use? Some hill climbing is as hard or harder than towing, but most people I know feel that any car would perfectly climb those. (The typical 'sunday ride' where every one on board is completely distracted and not paying the least bit of attention on the temp dash indicator... if the car ever had it!!!)
My guess is more toward the classic recently graduated "genius engineer" that dreams of receiving a company congratulation for proposing a reduction of the fabrication cost a couple of cents, multiplied by the many thousands of vehicles... as so on.
Sorry, I can't figure how to upload the image tof the pan taken with my cellphone and stored in my PC... I'll try to send it attached to an email message, but then I would need to show your email address, and that is not a good idea cause anybody would have it... sorry, I've never put an image here!
I can vouch for that. A divorced friend who calls from time to time called--quite worried--one day after a long hard drive. Colored fluid was running from beneath her car. I asked whether it was coolant or transmission fluid. She didn't know. I asked whether it was green or red. She couldn't tell. I told her to put a tiny dab on her finger and report whether it smelled/tasted sweet or oily. She replied "oily."
"Aha," I said. "You had an oil change yesterday, just before you left on your trip, didn't you? And you used that filling station near your house, right?"
"How did you know?" she asked.
I explained about expansion of transmission fluid and how to check it. Her car was still warm and she checked it on the spot. The level was right on. It had blown off the excess on the highway.
She asked how the transmission could have gotten overfilled and I explained the facts of life--expensive mechanics don't change oil or fix flats; high school dropouts do. She was stunned to learm about the "highly-qualified technicians" working on her car. Don't you hate to disillusion someone like this?
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