Things automotive engineers should be nut kicked for.

I'm sure we've all run across these issues. Today on my list is using random thread pitched that nobody ever carries.

A few months ago I had the diff bushings replaced in my 95 miata. First time I've ever someone to work on my car. Last few weeks it developped a noticeable clunk in the rear. I knew I was about to put the flyin Miata butterfly brace on so Id investigate then.

Well today I get under the car and both nuts that go on the bolts going through the diff bushings are missing. No problem, I have a massive collection of random nuts. Except these aren't the standard 12x1.25 or 1.75.

Oh no 1.00 pitch!?! What the hell!! No one in town has them. Fastenal will order them but they won't be here till Monday.

WHY!!! WHY! Some old miata engineer needs to pay for this.

I would like to nutkick the decision-maker who decided every fastener on a BMW motorcycle would be a torx head but not all the same size torx head. My "emergency" tool kit requires 3 different torx sizes just to get the bodywork/tank off. Trying to eyeball which one you need in poor light is maddening.

Whoever started the trend of snap together plastic interiors gets a but kick. Yes they go together quickly, and yes cars don't usually come apart that often, but I want to disassemble parts, not break them off.

I'll give my kick to the GM engeneer who placed the control arm bolts on my malibu. To remove these bolts, you have to lift the engine and trans to remove the motor mounts so you can back the bolt out of the arm. Had the bolt been flipped 180°, you could pull the bolts out with nothing in the way.

Honda for the pain-in-the-ass-in-my-life-right-now in intake manifold bolting design on the A20 engine where you can't actually get to the nuts on the bottom row with the head in the car.

Subaru Boxer engine spark plug replacement - What were they thinking? You have to maneuver in the tight space between the head and frame rail.

Honda for the oil fill location on the '12 Fit

VW MK4 - to get the timing belt off - remove engine mount. Needless to say installation is the reverse of removal. Oh and BTW there just happens to be one bolt that you can't get with a ratchet or a box-end wrench.

The Subaru spark plugs - yeah - worse if the engine is DOHC like the 97-99 Legacies or a WRX.

Automatic transmissions with lifetime fill.

Boxer spark plugs.

Anything that is kind of brittle that snaps together and invariably breaks.

The bitch clip on top of an E30 transmission that holds the shift linkage in.

NGTD wrote: VW MK4 - to get the timing belt off - remove engine mount. Needless to say installation is the reverse of removal. Oh and BTW there just happens to be one bolt that you can't get with a ratchet or a box-end wrench. The Subaru spark plugs - yeah - worse if the engine is DOHC like the 97-99 Legacies or a WRX.

This is the way almost all transverse timing belts are.

mazdeuce wrote: Whoever started the trend of snap together plastic interiors gets a but kick. Yes they go together quickly, and yes cars don't usually come apart that often, but I want to disassemble parts, not break them off.

The goal of the designer is to make the car fast and easy to assemble on the line. They could care less about the guy taking it apart 10 years, it's out of warranty by then. You can hate it, but they have their priorities set that way for a reason.

In reply to tuna55:

Well then everybody line up for a nut kicking!

icaneat50eggs wrote: WHY!!! WHY! Some old miata engineer needs to pay for this.

It IS for a reason. A very good reason. The same reason you cannot buy class 4.8 bolts in 12X1.5.

This way you cannot use any old random fastener you found to hold a wheel on your car. Certain metric pitches and diameters are spec'ed for certain applications and are not made in other classes.

It is actually brilliant and the sign of a well thought out design.

The Ford powerstroke 6.0 diesel.

These have made me so much money over the years but the real question was half this E36 M3 necessary??

My nomination is whoever designed the factory jack in the E36. Had one collapse into a pile of twisted metal on the side of the road and leave the car sitting on its brake rotor.

listening to the mother - berkelying bean counters

In reply to icaneat50eggs: I'm guessing you tried the local Miata dealer and/or any local Miata nerds aka spec racers?

My local mazda dealer was useless. They've been open about 3 months. My town of 200k in texas isn't really a hotbed of miata fans.

Any car that has a sharp edge on every possible surface in the engine compartment.......... I'm looking at you GM!

Very rarely is any of this stuff the fault of a real, actual, engineer. More likely the fault of living in a country without good availability of metric fasteners to the public, or not reading the service manual that tell you how to do the job efficiently (which may vary from general intuition), or just various cost savings measures.

Spark plugs on a single cam Subaru are easy, you move some easy to move stuff out of the way and you're done in an hour or so. Couple extensions, swivel or two, no worse than doing plugs on a lot of old OHV V8s, and you can usually see all of those!

As mentioned, most transverse timing belts end up routed around an engine mount that ends up being hard to remove, would you rather the car vibrate more without the big mount there? The PT Cruiser is a bad offender with this, but that's the fault of not engineers dictating the front be so narrow, and cost dictating it be FWD. Similar story with the battery inside the fender on some Chrysler stuff.

A lot of transverse mounted engines recommend removal of the rear mounted manifold(s) on the bench, after pulling the head, when doing work involving head removal.

I'd like to kick that Fiat engineer in the 60s who thought m10x1.25 brake nuts were a good idea, but it's not his fault the USA hates the metric system.

JtspellS wrote: The Ford powerstroke 6.0 diesel. These have made me so much money over the years but the real question was half this E36 M3 necessary??

You get to kick both Ford and International in the nuts for that one (and that 6.4 PS as well).

My candidates for nut kicks:

1. Using both SAE and Metric fasteners on an engine, with not much reason where they are used.

2. Newer HVAC systems, can they possibly make them more complex and hard to work on. I recently replaced the blend door actuator on the Bonneville, so you know where this is coming from. Also goes for heater core design, those engineers need more than a nutkick, special hell for whoever is responsible for the Dakota heater core placement.

3. Engines halfway under the cowl/windshield.

I'm sure there are more but that is a start.

mazdeuce wrote: Whoever started the trend of snap together plastic interiors gets a but kick. Yes they go together quickly, and yes cars don't usually come apart that often, but I want to disassemble parts, not break them off.

Honestly, from now on I will pay someone to do any interior work on my car. I needed to clean the sunroof drain tubes on my E46. I E36 M3 you not, that task eventually wound up including taking out both front seats so I could start the daisy chain of trim panel removal required to get just the back half of the headliner down far enough that I could access the channels. I ended up busting a couple pieces and costing myself $100 or so in new trim bits.

81cpcamaro wrote: 1. Using both SAE and Metric fasteners on an engine, with not much reason where they are used.

While this is crazy-annoying, after being in the supply chain, I totally get why this happened and why it's legit.

Interesting assumption that all engineers are male...or is t just all engineers who make stupid decisions? That I might believe.

Ohh, and a big ol' nut kick to wiring harness connector designers.

There is NO NEED for electrical connectors to clip/snap/clamp together in more than one way. You should be able to squeeze and pull to get them apart. Just push to put them together. Instead, you have to spend 20 minutes peering into the engine bay, on your back, in poor light, around a half-blind obstruction, just to see which particular little bit you're supposed to move for release. Then you have to figure out if it should be pushed up or down, left, right, or something else. THEN you have to be able to do that at the limit of your reach, with your arm and hand blocking whatever tiny glimpse of the damn thing you did have, with no leverage.

If whole guns can be designed so you can take them apart and reassemble them in the dark in the bush, you should be able to unplug any harness connector by feel in 1 try.