A blast from the past is revealed and gets rectified, and I take the time to appreciate some older pieces of engineering
So Eastern Hydroblasting has been getting a bit of business through the doors. Some of it has come through this column, so thanks to everybody who has got in touch either to bring us a blasting job they needed done or even to just to say g’day.
One such bloke was a fella named Steve who brought us the transfer-case out of its mid-80s Ford Bronco. Things is, he didn’t really know what the problem with it was. His mechanic reckoned the case was cracked somewhere, but Steve himself was betting on a leaking seal. Either way, the thing was absolutely covered in its own lubricant, so cleaning it up was step one. Which is where we came in.
We took a quick look at the case while it was still on the back of Steve’s ute, and Bondini immediately points out a nasty looking crack in the outer casing, just below the boss for the front output shaft.
“Ah,” says Steve, “the mechanic was right. That’ll be the leak, then.”
Okay, so what do you want us to do, then, Steve? We can pull the thing apart, have it welded up and reassemble it, or we can pull it to bits, give it back to you, you get the crack fixed and bring it back to us, or you can take it to an engineering shop and no charge from us, nice to meet you.
But Steve didn’t want to muck about, so he gave us the go-ahead to do the whole job. A lot of people like a nice, simple process without running from shop to shop, losing bearing needles every time the pile of parts changes hands. Suits us.
So we pulled the transfer-case to bits and split it to get at the crack. Until we turned the cover over to see where the crack had extended to on the inside. Except, we couldn’t see it. No crack here. Here, no crack. What’s going on?
So we started to look at the ‘crack’ a bit more closely. And when we did, you could see that the phantom crack was actually a die-casting mark. But take a look at the photo and tell me you wouldn’t have figured a transfer-case covered in oil with that mark on the outside of the case wasn’t due for a date with the TIG welder.
So we phoned Steve back to give him the good news that he wasn’t up for a welding job, and then we put our heads down, tore the case to bits, hydroblasted the bits to make them pretty again, linished the casting mark away to prevent the next poor bastard falling for the same thing, changed the seals (yep, including the leaking one) checked the bearings (fine) and the chain that drives the forward output shaft (a bit worn, but fine) and then bolted it all back together.
A few days later, Steve picked it up and swore he’d never seen such a pretty transfer-case. He’s even changed his mind about painting it, and reckons he’ll leave it au naturel. That’s hydroblasting for you.
Eric weighs in
Last issue, I had a red-hot crack at the idea of willingly allowing an insurance company to electronically monitor my every move on the road. The basis of my angst was simple: What if the information was to fall into the wrong hands and was used against you to hike your insurance premium or – gawd forbid – leave you open to retrospective speeding fines. I mean, it’s bad enough now with cameras everywhere watching you like a hawk, without inviting your insurance company to ride shotgun, right?
Anyway, somebody who agrees with me is long-time UC reader Eric. But he also has a few bees of his own under that bonnet, starting with the myth that ‘casual speeding’ is the major cause of death and injury on the road.
“As far as my Highway Patrol son and myself are aware, this statement is totally at odds with the facts, and implies that this form of ‘speeding’ is the primary and singular causal factor.”
Geez, Eric, tell us what you really think. And isn’t it interesting that even his son – a serving Highway Patrol officer – can see that nonsense for the pile of crap it is?
And there’s more from Eric: “Speeding per se, for yourself and myself, can be defined simply as driving too fast for the prevailing conditions. But of course, a politician’s idea of speeding is when the speedo is registering a greater number than that displayed on a roadside sign.
“My personal take on this is that 95 per cent of the drivers feeding this revenue stream (often as great as one million dollars per day), are not the ones having the accidents and killing people.
“Wouldn’t one like to get their hands on those drivers’ accident records and along with road accident investigators’ findings, and have published and advertised on television the real causes of road accidents?
“Some of these serious accidents start to unfold in the driveway of the person’s home, the minute they fire up the engine and reverse out on to the road. Such is the mindset of hundreds of people driving motor vehicles every day of the week.”
Eric, old mate, I couldn’t have put it better myself.
The statement that always annoys me is when a spokesman for the cops grabs a microphone, stares earnestly into a camera and claims that speed was a factor in the crash. Of course it bloody was. If the car hadn’t been moving (ie: travelling at some velocity) the crash – unless it was hit by a falling speedboat – wouldn’t have happened. It’s like saying a drowning involved water. Idiots.
Wheel to wheel contact
Have you ever had a close look inside an ancient piece of engineering such as a Model T wheel?
Neither had I until pretty recently, when I started to sort out the various bits and pieces I had stockpiled in order to rebuild the wheels on my inherited 1925 Tourer. Actually, stockpiled is a bit misleading, because the bits and bobs have found me, not the other way around.
I’ve mentioned this phenomenon before, but once people know you’re in possession of something, they figure you might like to have the pile of random, rusty spares for that same thing that they’ve had lying around for decades. It’s a very generous thought, and I encourage it.
But in this case, I think the end game should be to retain as much of the original Model T my father-in-law entrusted to me, in the interests of preserving history. Not to mention memories.
That didn’t stop me having a close look at how one of my spare wheels is constructed, though, and it’s a fascinating thing to see close up. On the surface, it’s just a steel rim with wooden spokes, but when you remove the steel hub (which also forms the brake drum on the rear wheels) from the centre of the wheel, you can see close-up how the thing is constructed. And it’s brilliant.
I mean, this is dead-set, old-school carpentry. Check out the way the spokes are narrowed towards the centre so they form the perfect circle. Some poor bastard had to calculate those angles without a pocket calculator or a smartphone. And then, his mate had to use hand-tools to shape each and every spoke-end so that it dovetailed with its neighbour and formed the physical version of the theoretical article.
Okay, so old Henry Ford was able to turn a lot of these tasks into what we now call process engineering and production, but the very first ones were all made by hand and designed by nothing more than brain-power and the ability to understand how different materials and designs worked in the real world.
Meantime, it surprised me a bit that the holes that accept the studs that secure the steel hub are drilled through the edge of each spoke, so that the hole occupies two adjacent spokes. I would have thought (and trust me, I’m no engineer) that drilling through the centre of every second spoke would still have given you the required six points of attachment, as well as not allowing the spokes to fret on the studs. But then, when you think about it a bit more, you realise that the hub, once tightened onto those studs, is going to hold the whole thing rigidly.
Certainly, the bigger risk, I started to think, would be that the spoke taking the weight of the vehicle at a particular point in the wheel’s rotation, would be trying to force the opposite spoke off centre. But again, the steel hub would prevent that. More likely is that the angle of the cut of the spoke where it slips under the hub, would try to push the adjacent spoke sideways under load. But the way the spokes are intermeshed on that magical angle is what probably prevents that.
Mind you, if the condition of the timber in the wheels on my car is anything to go by, the system wasn’t perfect at eliminating movement. That said, my car has sat in a dry, hot environment for many decades, so when the timber dried out and shrank a little, that’s when the movement would have started. And let’s not forget that the tree that gave up its timber to form those spokes was probably being cut down and milled while World War I was raging on around the planet.
All this head-scratching about spoked wheels reminds me of when I was a kid and I suddenly had one of those mechanical moments of clarity (well, it was explained to me by a grown-up, but you get the idea). And that was when I finally realised why my pushbike wheels didn’t buckle under the weight of the rider, even though the spokes were just skinny, flimsy little bits of wire.
The concept (and mechanical reality) that the spokes were weak in compression but hugely strong in tension was the clue, of course, but when it finally dawned on me that the bike does not ‘stand’ on the bottom spoke, but actually hangs from the top spoke, a huge chunk of the universe fell into place for the young Morley.
And to be honest, I haven’t stopped being amazed by this stuff ever since. Which possibly explains why I’ve just spent an hour staring at 100-year-old carpentry from a Model T Ford.
The danger now is that I’m about to go down the fascinating (but complex) rabbit-hole of timber steaming and bending as I investigate the Model T’s touring body. Is there anybody out there still doing this? Can I come and watch? Would you lot like to see a short video of the process?
Hit me up.