Saturday, 3 July 2010

Not Grit in the Gears...

I am, I admit, a serious abuser of machinery. I have toys.
So, the green thing, as seen above, has been dormant since about a year and a half ago. I was using it, at work, to pull tree stumps out of the ground and drag them up the field. Seeing how successful that activity was proving (our general labourer had spent all the morning trying to dig out one stump), I decided to get involved and ripped six out of the ground in under an hour..., my boss suggested that I might try the same tactic on the steel barrier-posts in the car-park.  And I, being a fool, said... "Okay".
Now, of course, when you're on a field, on grass and earth, the amount of torque you can put through any one drive-line component is limited by the coefficient of friction between the tyres and the surface beneath them. On grass and earth, what happens is the wheel grips for so long, then spins, throwing out a divot, or a steady stream of muck. The force is dissipated by the slippage and displacement of earth.
When the object you're pulling at is a six inch square, five-foot high steel post, filled to the top with concrete, and embedded to a depth of two feet, in concrete, and the tyres are on very grippy tarmacadam  surfacing, then the wheel doesn't spin. Something else happens.
I thought I'd broken the transfer-box, because I could still drive in low-ratio four-wheel-drive mode, but transfer to high, and zip. Just a whirring sound. So I was convinced I'd have to do a gearbox/transfer box transplant, and as it's not too far back that I'd done a complete, from the ground-up rebuild, I was not looking forward to the prospect. today, I decided to go and get started on an investigatory process.  First thing was, the damn thing wouldn't start. No fuel... well, fuel in the tank, but none at the carburettor, so I proceeded to strip out the fuel pump, dismantle and check. The filter-gauze was blocked. It looked as though it had been varnished. There's some nasty stuff in unleaded fuel.  It doesn't take kindly to being left standing for a year and a half, so that job took a couple of hours. Once the fuel was getting to the engine again, I could drive to a more comfortable working place, and jack the wheels up. 
Now I could engage drive and see what was happening. In 4-wheel-drive mode, both the front and rear propshafts were spinning, but only the front wheels were obliging. 
Well, that's a relief, because it rules out the dead transfer-box hypothesis. Duh. If I'd thought about the time of failure and the nature of the fault, I should have already figured out the most likely culprit. If it was driving in low ratio but not high, what's the difference? High uses  2 wheel drive as default, 4 wheel drive is selected by thumping the top of a big yellow button on top of the transmission tunnel. Bang. It drives. So the front wheels are doing the biz, but not the back ones. Obvious. What a muppet I am. If the propshaft rotates but not the wheels, it's either the differential, or a halfshaft... So I take off a drive flange.......

Oh dear. The tooth-fairy's been playing about in there, chewing at what should be a nice flat-faced hex-nut....

This is where the toothy bits came from. Very hard, very tough  steel, twizzled apart, like play-doh.

Surely that's not supposed to happen? 
And of course, I've been trying to curb my hoarding tendencies, and sent the spare axles to the scrap-metal dealer a year, after the rebuild. I've still got a lot of spares, but.... not the bits I need to fix this. Tomorrow, I'll go see my pal Ken,  and see if we've got a spare set stashed in the pile of really important stuff that his wife keeps telling him to get rid of.

Revised Text: They're not hard to get at all, new, and, would you believe, cheaper than four gallons of unleaded!
That's ridiculous, but  heartwarming; forged, machined, heat-treated and not eye-wateringly expensive. Oooh! Shiny new parts! Might just put them together tomorrow!

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  1. oh goodness, you and my husband would get along wonderfully! he loves abusing machinery too lol. i sure hope you find the parts you need, that truck/jeep thing is cool!

  2. Well, I didn't get the parts today, but that might be because I didn't try. Just went out and enjoyed the sunshine.

    But you're right, the green thing is cool, and I should have been out, with the top off, bumping over a rocky track on the heather-fragrant moors.
    Ask hubby if he's got a ten-spline halfshaft for a '62 land-rover in his abused machinery bit-box, will you?

  3. one always hoards too much- and never the bits that break!

  4. A bit too much engine in your toy if you ask me. People prone to pulling things out of the ground should be protected with less horsepower. Wasn't it you who once told me that there was some sort of ratio between horsepower and I.Q. that needed to be applied before attaching cables to stumps and such? I think it was you, but I forgot the ratio.

  5. gz: one never hoards quite enough.
    When I become a multi-millionaire, due to a lottery win, or that chap whose name i cant recall who died in the concorde crash, leaving billions but no obvious heirs and now his lawyers have tracked me down as his only surviving relative. They're incredibly thorough, aren't they, but i fear they seem to have missed out the existence of my siblings, so I'll either have to bump them off, or come clean and share... but what of the cousins...oh dear...
    anyway, when I'm a millionaire, I'll have a 200 thousand square-foot warehouse, with racking, and fork-lift trucks, in order to hoard more stuff. but I'll have someone to index it, so when I come in and say "have I got a manifold stud for a 1972 volvo?", he'll just fire up the forklift, and go to bay seventeen, shelf twelve, and retrieve a crate.
    And in a neatly stacked and labelled box, will be a full set of exhaust studs for a 1972 volvo. "I brought you the new studs," he'd say "You have a used set in bay 34..."
    "Oh, that's okay" I'll reply, "I didn't actually need one, but I was just wondering, last night, if I had one. I mean, in case I ever happened to buy a 1972 volvo, with a broken exhaust manifold stud....."

    Oh yes. I need more storage.

  6. Max: Horsepower in the green thing is not exactly excessive. If the engine and its ancillaries were new, it might, on a good day, manage 75 hp, but it's forgotten all that newness a long time ago. Now, instead of brute force, it tackles obstacles with patience, and wily cunning, a bit like its master.

  7. we must be related! that same guy's been trying to track me down too! i'm patiently waiting for my check to come. lol

  8. Hardly its master, and hardly wily. Or did you mean as in Wile E. Coyote? Ah, well, I'll defer to you. But 75 hp or no, it was more than the gears wanted. You can do the torque translation. I liked the story. Reminds me of once when I tried to blow out the rear end of an old push-button Chrysler. I had an excuse though - I was 16 years old. You weren't even TRYING for damage.

    As long as it ends well, as I'm sure it will.


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