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sexton last won the day on June 26 2018

sexton had the most liked content!


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  • Location
    Whitby, Ontario, Canada
  • Interests
    All things mechanical.
  • Occupation
    Mechanical engineer

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  1. Forgot to mention, I can't find this part in the parts manual so I don't have a part number.
  2. I'm working on a Samson. When the starter button button is pressed, the motor spins up but the pinion doesn't kick out to engage with the ring gear. The starter was rebuilt about a year ago and just installed. I took it apart and the reason for this is obvious. The segmented ring installed in the solenoid bore that pushes the pinion out is just missing. The rebuilder forgot it, lost it, or just decided to leave it out because it is a pain to install.. Anyone know where i can get this ring and the garter spring that wraps around it? Thanks, Malcolm
  3. I've read through your attempts to unscrew the end cap of the equilibrator, item 48 in the parts diagram, and I don't see anywhere where you specifically heat the bugger up to red hot with an oxy-acetylene torch. That's what it needs! And by the "bugger", I mean the flat face of the end cap and the region of the cylinder with the internal threads. I don't know the diameter of the cylinder but you may need to buy or borrow a crescent wrench, aka adjustable spanner, large enough to fit the flats. And it must fit snugly! Soaking in the huge variety of penetrants always suggested for this kind of problem doesn't hold a candle to heat. The Belleville washers will not suffer from this heating as the thermal conductivity across an interface is very poor, especially if rust is involved. Malcolm
  4. John, the guys at the nuke plant used to bring in an electrical discharge machining contractor when they broke a stud on a critical piece of equipment. Don't know the price but it didn't seem to be too expensive. Malcolm
  5. Well spotted, Citroman! It is indeed 0.829. So that's what the 2500/.829 means on the back of the tach! Malcolm
  6. John, i worked at a nuclear plant, so steam, heat, and highly stressed bolting. We had a very good metallurgical department who identified failure causes and we saw our fair share of bolting SSC. 115 ft-lb on a 7/16" stud is 140,000 psi stress in the stud. High quality grade 8 bolting has an ultimate tensile stress of 150,000 psi. So those studs are extremely high tensile material. No wonder they were susceptible to SCC. And no wonder you had difficulty drilling and tapping it!
  7. Not necessarily. This is a crash shift, no synchromesh, so if the gear teeth don't line up with motor shut off, they won't engage. Try kicking the motor over with the starter and trying again. I agree with sirhc, on a CVRT and a Ferret, you have to shift forward to reverse and vice versa very firmly, with no delay. And I mean firmly. Malcolm
  8. Found this late but I can tell you the Centurion tachogenerator which is driven by an idler gear off the cam gear is an AC generator that creates an AC voltage that varies as rpm. So the tachometer is really just an AC voltmeter calibrated in rpm. At 2500 crank rpm the tachogenerator generates about 4V AC. One wrinkle is that the tachogenerator is spun at 0.892 of the crank speed, for reasons that only a British designer would know, so when test spinning the tachogenerator at 2200 rpm, the tach will read 2500 rpm, the redline for a Cent. This doesn't make for an easy conversion to other vehicles. Malcolm
  9. Very interesting, John. Sounds exactly like stress corrosion cracking, which is surprisingly common for high tensile bolting under a lot of stress and seeing moisture and heat. I guess studs were larger diameter below broken 7/16" section since you drilled and tapped for 1/2"? What is the torque on these studs? Malcolm Malcolm
  10. Paul, Sorry to hear about your health woes. Sounds painful! We have made some progress. We have a spare clutch in poor condition and one of the clever guys here suggested using just the clutch shaft as an alignment tool. Seemed like a good idea, so I stripped the old clutch down and it looks like we can drop the engine in, slide it towards the front, install the bare clutch shaft (well, not completely bare, it has the drive gear mounted at the crankshaft end and the output shaft flange at the gearbox end), slide the engine backwards to locate the drive gear in the end of the crankshaft, bolt the flange up to the gearbox input shaft flange, and check the alignment by mounting dial indicators on the clutch shaft and clocking the crankcase face and the gearbox flange face using the two surfaces shown on the drawing below. The parts of the old clutch we will use are coloured in (faint) orange below. I think it will work! Thank you, Mike! So we're getting closer to having her running. All the wiring associated with running the engine has been repaired, the driver's instrument panel and switchboard have been rebuilt, alternative instrumentation for coolant temperature and engine rpm has been installed (the original stuff was not repairable), new batteries and cables are in, the clutch has been overhauled, all the control linkages from the driver's compartment to the throttle, brakes, clutch and gearbox have been cleaned and lubricated, the long range fuel tank has been cleaned out and will be used as the main tank,, new fuel tubing run to the engine, the fuel filter rebuilt with a new element, a repaired fuel tank selector valve installed, all coolant tubing and the engine mount frame have been repaired and pressure tested, the coolant header tank has been repaired and pressure tested with rebuilt pressure relief/vacuum breaker valve, the main and steering brakes have been cleaned and lubed, the oil tank cleaned and pressure tested, the oil cooler cleaned and pressure tested, one rad has been cleaned and pressure tested, the other is in progress, the air filters have been cleaned and rebuilt, the gearbox selector forks and shafts removed, cleaned and lubed, suspension lubrication is in progress, one exhaust pipe between engine and hull has been repaired, one still has to be done, the fans have been rebuilt with new bearings. The main outstanding tasks are the rad repair (leaking end cover gaskets) and the engine/gearbox alignment. We're getting close. Malcolm
  11. Hi, Paul, Thanks for responding. I'll send you a PM. Can you remember if Barney used the very special tool specified in the Manual to do the gearbox-engine alignment? Because I suspect, like so many special tools and elaborate procedures in the manual, the guys in the field found more practical ways of doing the job. That's what I need! Whoever took the drivetrain apart before my time bagged and tagged the gearbox alignment shims so I used those when installing the gearbox. That gives me some confidence that at least the gearbox- final drive alignment is ok. Malcolm PS. It's unusual for valve timing and magneto timing to slip. What do you figure is happening?
  12. Hi, Caddy, I'm resurrecting this old thread in the hope you are still around. I'm getting close to installing a Mk 4B Meteor in our Mk5/2 Cent at the Ontario Regiment Museum in Ontario, Canada. It's a 1974 rebuild by Scottish Aviation, and it runs well on the test stand after some magneto and carb cleanup. I am really interested in the engine installation photos you posted. It looks like you removed the starter, generator, and oil filter, then dropped it in sideways into the hull and rotated it 90 degrees into position. Is that correct? I wasn't planning on removing the oil filter but you say that's needed. We have the fans installed, but you didn't. Is that a show stopper? It also looks like the exhaust manifolds weren't installed. I know we have to remove the right hand one to allow installation of the oil tank post engine install, but is there a reason you had neither installed? How did you align the engine to the gearbox? There's quite an elaborate procedure for this in the manual, and I'm struggling with it. Finally, did the Mk 3 get running under its own power? Regards, Malcolm PS Mike, John's getting back to me.
  13. Hi, I'm still plugging away at getting our Mk 5/2 Centurion drivable at the Ontario Regiment Museum. I'm lubing the long-neglected suspension now, and have a question about the two shock absorbers at the top of each large suspension unit. They are supposed to be submerged in a reservoir of a light ISO 12 viscosity hydraulic oil and they draw from that reservoir in operation. When I removed the fill plugs I found all of them very low in oil, possibly dry, and one with a fill of grease, or at least grease had been slathered down in the fill hole. I was surprised at the lack of oil because none of them showed any signs of leakage. Other oil-filled assemblies like the final drives and gearbox still had clean oil in them up to the correct level. Then a member here who had served in Chieftains expressed his surprise that's the Cent has shocks, because he said the Chieftain didn't. Now I'm wondering if it was decided the Centurion shocks didn't do anything useful and were just given up on, in the sense that no further maintenance was done on them. And the Chieftain consequently didn't even bother with shocks. Seems strange to me, but I thought this forum might shed some light. Malcolm
  14. I got some good replies on MLU if you need some info on this tool. Malcolm
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