Oldsmobile Hydra-Matic Drive (1947) [pdf] | Hacker News Reader

Oldsmobile Hydra-Matic Drive (1947) [pdf]

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47 pointsuserbinator41 comments

Haha I imagine I am one of the few that frequent this site that have actually rebuilt a couple of these - happened back in the 80’s when I worked at a transmission shop. Even then it was an odd duck. Definitely brings back some fond memories of a simpler time with a whole lot less responsibilities.

Not sure if it was one of those, but we had a Citroën 2CV with a funny clutch mod. It still had a stick, but you could release the clutch careless or even just stop using it.

One night I took a shortcut through a neighboring field. When I realized the rain had swamped it completely it was too late to stop. I was sure that the car would stall in a few meters, so it was a huge surprise that it just skated over 100 m of mud.

Somehow the device drifted internally instead of letting the wheels spin on the mud.

People was very happy with Land Rovers for the difficult country paths, but 2CV were superior and that one was superb.

For those who've never experienced one:

Navigating ploughed fields was part of the design brief for the 2CV (note for Americans: it's pronounced "der shev-VOH", not "2 C. V.")

The light weight was the biggest factor in their performance in the mud. Those skinny wheels put a lot of circumference down. And the suspension travel was generous.

On the road, the 2CV was a bouncy ride. I would not describe it as comfortable, but it was certainly not harsh - a 2CV will bounce you about but never jolt you. Dignity without gravitas, perhaps.

If you ever meet an owner, ask for a ride. It's an experience. I adore them and would love to own one, although note that I'm not in the dating scene any more. And yes, Jay Leno has one.

Wasn't one of the design parameters for the 2CV being able to cross a field while not breaking eggs in a basket in the seat?

Yep!

https://silodrome.com/citroen-2cv-history/

and here's a clip from new-new Top Gear, I think I saw Jeremy or May do one years ago but can't find it sadly.

https://www.youtube.com/watch?v=qQTgwJ6pLHE

Not surprised yours skated across a muddy field.

Not surprised yours skated across a muddy field.

My father loved going hunting. The 2CVs were his secret weapon to reach very inaccessible places and he owned a handful over the years. But, trust me, none of them, except the modded one, would have passed that field.

I love it that they felt the target audience wanted to understand how it works, at least in broad strokes. Though I’m a little disappointed that the value prop is “right hand can be in wheel, left foot can be relaxed”. If there’s one thing I’ve learned from Mad Men, it’s that the right hand is free to hold a cigarette.

And wow look at all the white men, and the poor women having to deal with the complicated manual transmission and have her husband explain the torque converter.

I think it's less that they worried about whether or not people wanted to know how it works, and more that they needed to know. New fancy technology is generally poo-pooed by people. Why do we need fancy auto anything when a stick and clutch worked for years? Well, here's some fun graphics to explain!

These days it seems people are more content with "it's magic" as the explanation.

Then again, how could you explain complex automotive systems like Tesla's self-driving in a way that's as lucid as this? I think at some point, companies just gave up trying to educate and went for "trust us, it works" instead.

Perhaps the non-explainability of Tesla's "full self-driving" technology bears some relationship to its track record of not delivering on its marketing claims.

The other huge contrast if you're used to ads today is the huge amount of text - people back then seemed to both be more patient and willing to read.

I think this was, likely, showroom material rather than magazine pages

There was less to distract back in those days

> the right hand is free to hold a cigarette

Crazy talk. You hold the cigarette in the left hand so you can flick the ashes out the window.

the first 'real' automatic like they exist today -- was eventually replaced by the PowerGlide, which yet again set a whole bunch of standard practices in place.

Beloved by hot-rodders everywhere for their ease of install and ubiquity in the field. My father has one in his project right now.

He, being a product of marketing like this, proudly responds with "No, Hydramatic!" when asked if his car has an automatic transmission. Cracks me up every time I hear it.

I have a friend that just spent the last two years building a fox-body Mustang drag car with a turbo-charged big-block Ford engine in it. I was surprised to learn he put a Powerglide in it. I guess the Ford folks even use the Powerglide. The US automotive aftermarket is amazing.

You can get pretty standard setups to mate almost anything to anything, and if you’re willing to fabricobble you literally CAN mate anything to anything.

I was puzzling about Hydra- vs Hydro- the diagrams don't claim that water is involved, but I wondered if there was some sort of ingenious multi linkage gearing involved that might merit Hydra. Still really neat.

It's a portmanteau of hydraulic and automatic. Of course the former was originally only referring to water, but later became used to refer to any system based on fluid pressure.

(Fun fact: "hydraulic elevator" in the late 19th and early 20th century often referred to one that actually used water.)

Right, and the "-a-" following "hydr-" is the initial letter of the word meaning "pipe" in Greek, so at its origins hydraulics was about water pipes, but now "hydraulic" is used for any devices that transmit forces through liquids, while "pneumatic" (from the word meaning "blowing") is used for those that transmit forces through gases.

I think that it is referring to a hydraulic mechanism, not the mythological Hydra.

TIL what the first line of "Greased Lightning" means.

My thought also. But who races in an automatic?

Lots of people, if they weren’t banned from F1 for being too good. The drivers are just shifting gears to keep the audience from getting bored since 1994.

Drag racers. The current trend is very high-horsepower turbo-charged engines with lots of torque and a two-speed "auto" is all they need and there's only one shift in a 1/4 mile run.

I put "auto" in quotes because the automatic function is usually removed and you have to shift it manually.

The torque converter effectively provides an additional extra-low gear right at the launch which is very helpful for acceleration, and there's also no interruption in power during the shifts.

They're usually superior in dirt for FWD (dirt track, rallycross)... the torque converter helps a lot.

These were used in legendary Rolls-Royces from the 1960s (Silver Cloud, ...). It is a good sign that this thing was so good. I had the chance to drive one of them and it still runs well after >60 years, sometimes even more accurate speed changes than some automatics from the 1990s.

I'd only known of the far more famous TH400 being used by Rolls-Royce, so I looked it up, and found that they did use the original 4-speed Hydramatic before that, but not the smoother "controlled coupling" variant --- here's a long and detailed (4 pages) article about it:

https://ateupwithmotor.com/terms-technology-definitions/roll...

It also mentions the same story in the sibling comment about them trying to improve the parts, but ended up making things worse.

There is a story (my Dad told me) that Rolls Royce took the part from General Motors and refined it by polishing surfaces and otherwise correcting what they thought were manufacturing defects. But after the refinement, the transmission no longer worked! There was no longer sufficient friction inside the mechanism to transfer the mechanical energy.

My best memory of a Hydramatic is the 1976 Cutlass I had in high school. Rear-wheel drive. On a snowy day you could slam the transmission into reverse while still moving forward and whip the tail end around realllllyyyy fast.

Wasn't too surprised when one morning the car refused to go into drive at all, only reverse.

I love the style of this advertising/design, it reminds me of old encyclopedias my nan had when I was a kid.

>Nothing for your left foot to do

I never quite understood why automatic cars make you operate the gas and brake with only your right foot to this day.

Wouldn't it make a lot more sense to have the brake pedal on the left now that you don't need to operate the clutch anymore?

When I got out of the military, I bought a second-hand Olds Cutlass, with a rocket 350 and a Super Turbine two-speed automatic transmission. It was cool for it's time, but if you're used to modern tech, none of them would impress you.

In 2013 I purchase a 1968 Ford truck for a restoration project. It had the original manual in the glove box, mind you this truck was beyond beat, some how this survived... Its a glorious relic of print design, so I kept it.

The insanity of digging up stuff that has stored several millennia of sunlight and releasing byproducts when used NOW still staggers me

i think that stuff is the only reason we have a chance to get off this rock

what other species out there could claim a millions-of-years old energy store that has been conveniently brewing right beneath their feet, just ripe to exploit when they finally have the brain cells to bang together and make the spark?

today we have better stuff to burn and imo we should move to renewables anyway, but long tails and sins of our fathers...

Another potential component of the "Great Filter"

IQ drop since 1947 is insane. Imagine husband and wife having a dinner conversation about how automatic transmission works, using a pair of fans to illustrate the principle? I assume back then it was a commonplace idea that they would be capable of understanding and interesting in these things, else how did the idea end up in the pamphlet?

On one of Jay Leno's YouTube posts he says something like "an owner's manual used to tell you how to adjust your valve clearances; today they tell you not to drink the contents of the battery."

They used to be designed to inform the buyer how to do nearly anything.

Now they instruct the buyer to do nothing lest they incur legal liability.

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