Over engineering

[shDK]

Hi all.

Is it just me. Or is it like the car manufacturers over engineer things more and more often, or just make things plain stupid.

Just today.. I was helping a coworker changing front pads and discs, on his Chevrolet Cruze. He bought the new parts at a local Chevrolet dealer. He got new pads, new discs. And 4 new pad bracket bolts. Apparently the pad bracket is mounted with stretch bolts. That must be changed every time you loosen them. And must be torqued 100 nm and 65-75 degrees. Simply insane in my opinion.

3 weeks ago I helped changing a cambelt on a fiat. The engine had to come out to do so. Took 2 days. Some cars needs to have bumbers removed to change light bulbs. And so on and so on.

My dad has a old vow type 2 for fun. There you can pull the engine in 30 minutes if you have done It before. You have to adjust valve clearance every 2500 km. But it only takes 5 minutes. Kind of a setback compared to modern cars.

Have a nice weekend.

 

[Wolf359]

They're not over engineered, they're under engineered. When they're first designed, they're very complex, as expertise grows, it can be made simpler and easier to fix.

 

[OneEyeJack]

It would be nice to have a list of vehicles with maintenance difficulties to help in the process of picking that next car.

Even if you don't do all that work yourself, someone does and that could be expensive.

A friend claims that pickups sell well and last a long time because most of them are easy to work and don't require special tools and a lift. It's easy to determine which ones are a pain to work on and they can be avoided. With many cars there are some nasty surprises when it comes to just doing routine stuff.

 

[i_hate_autofraud]

Auto makers keep dealer mechanics employed!

 

[MolaKule]

They are not over-engineered.

They just contain more sophisticated Module programming and useless electronic gadgets.

 

[ecotourist]

I would say they're under-engineered. A good engineering design would include ease of maintenance.

 

[IndyIan]

Originally Posted By: Wolf359
They're not over engineered, they're under engineered. When they're first designed, they're very complex, as expertise grows, it can be made simpler and easier to fix.

I can see why head bolts are single use torque to yield because of the different expansion rates of Al and steel. Iron brake calipers held onto iron hubs with steel bolts? For 50 years engineers didn't need single use bolts, what's changed?

 

[Ethan1]

Cars are now designed for assembly rather than service.

 

[AirgunSavant]

It shows bad engineering. I had seen that on many UK guns.
The idea was not so solid at first and they kept on adding to it to make it work.
Great engineering is making things modular and easily serviced.
Like my old 67 GTO- you had to take off the AC comp. to change a spark plug. Nice!

 

[Kuato]

Originally Posted By: i_hate_autofraud
Auto makers keep dealer mechanics employed!


This. If they have their way, the days of working on your own vehicle are over.

 

[edwardh1]

what sou;ld be nice, sort of like the rating system for safety from the IIHS , bad fair average good excellent
would be a maintenance system based on the difficulty of say 5 service items
brakes? Plugs? water pump assembly? radiator replace what else?

 

[edwardh1]

I don't even like the complexity of the high tech ignition keys. Nationwide I bey that cost exceeds the cost of stolen cars.

 

[BrocLuno]

Originally Posted By: Kuato
Originally Posted By: i_hate_autofraud
Auto makers keep dealer mechanics employed!


This. If they have their way, the days of working on your own vehicle are over.


No, the days of buying new product are over, or getting closer ...

 

[Kawiguy454]

I was IT support in the ford product development center supporting the 3D CAD designers. That was some years ago now so my guess is that the reason is they are cheaper or lighter bolts. Things are not done for no reason.

You want a cheaper car that gets better mileage right? That means saving pennies and grams by doing seemingly dumb things from an old skewl perspective.

 

[fdcg27]

...and the average second or third owner of these cars doing a simple pad slap would have no idea that he needed to replace the bolts and torque them carefully with the torque wrench he doesn't have.
Lamps should also be easy to replace and not absurdly expensive.
These are safety items that can properly be regulated by NHTSA unless we'd all feel safer letting the manufacturers build what they want as they want to at the cost of having a bunch of aging cars running around on iffy brakes and dead lamps.

 

[Trav]

TTY bolts have been used on many components for decades on some German and euro cars, they resist vibration loosening without locktite or lock washers, they act like a spring.
They really help to prevent leaks and shifting of parts that can shear gaskets, the downside to them is they have to be replaced after use.

Keep in mind that a lot of service manuals especially German ones state the bolts must be replaced even if the bolt is not TTY, just because the bolt requires a torque spec that includes +x degrees does not make it a TTY eg Honda crankshaft bolts.
They claim its a safety thing because it may have an OE loctite coating on it. I call it a money maker. To find out if its TTY bolt just measure the old and new one with calipers if its the same length then its not TTY. TTY bolts have a reduced shank diameter (smaller than the threads) this is the calibrated yield point, most caliper bracket bolts are not TTY they probably had red or blue loctite on the new ones.
MB use to give a spec for TTY head bolts, if they were below that spec they could be reused, they don't do that anymore.

 

[ecotourist]

Originally Posted By: edwardh1
what would be nice, sort of like the rating system for safety from the IIHS, bad fair average good excellent would be a maintenance system based on the difficulty of say 5 service items brakes? Plugs? water pump assembly? radiator replace what else?

This is a very good idea. What we need is a website that rates vehicles, by year and model (Honda Accord V6, Honda Accord I4), for common repairs and maintenance. Rating would include difficulty/time, special tools required, and cost of OEM parts. That should give a pretty good indication of cost of repairs at a dealer as well.

I'd expand the idea to include a few simple things like engine oil and filter change, engine air filter replacement, etc.

 

[Ethan1]

There's a website that does this for cell phone repair, of all things.

 

[Wolf359]

Originally Posted By: i_hate_autofraud
Auto makers keep dealer mechanics employed!


Most dealers are independent franchises, actually I don't think any auto maker besides Tesla owns their own dealership. So they actually have no incentive to keep them employed although I suppose if too many dealer franchises went out of business for an auto maker, it'd be bad for business. The auto makers also offer extended warranties too and they have to pay the dealer for those warranty repairs.

It really boils down to how much they want to spend engineering a car that will only be in production for 3-4 years before a new model comes out.

 

[mr_blackstock]

I think the issue has less to do with engineering, over or under, but more to do with fitting the car parts into a smaller and smaller shell, so passengers have more cabin and luggage space, and the enormous technology that has gone into crumple zones and strengthening without adding weight, has in many ways used up every little bit of space everywhere!
Also, I think that with finer tolerances being engineered into mating surfaces, ie no gaskets, and improved and cheaper metalogy, and improved computer modeling has made the modern car so reliable that replacing, or needing to replace an item, may not occur in the forseen lifespan of the car, which may 8 years at most.
With the older cars there seemed to be many instances where constant maintenance or frequent repairs were the norm, yet many modern cars seem to last for years with very little issue... in a general sense