The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => Gearbox, Clutch, Primary => Topic started by: Alex kettle on 14.11. 2020 15:24
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Who can enlighten me on how to remove this gear selector pin. I noticed it is threaded on the inside, have given it a gentle tap but is easier to ask here than damage something. I’ve looked at the scans but hasn’t helped me work it out. I’m sure a dozen of you know.
Thanks in advance
Alex
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Alex. Service sheet 311 says the thread is 1/4 CEI, the same nut end thread as oil pump studs, rocker cover studs and sump studs. Other ends of these into alloy are 1/4 Whit. Warm the casting (hot air gun) and use a suitable 1/4 CEI bolt or stud and nut to draw it out.
Swarfy.
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Cheers swarfy. I googled that service sheet number and was able to find it. So just to be clear, if I warm the case and screw in a 1/4 cei bolt and keep winding it will self extract?
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No, you need to pull on the screwed in bolt. The only way it would self extract is if the pin is threaded all the way through, your picture shows it isn't. Better to use spacing washers etc, with a draw bolt or draw nut on a stud. Pull it with a slide hammer or similar if you have one. With the casting warm it should come out easily, wear ridges may impair movement so proceed with care.
Swarfy.
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I was thinking a slide hammer after reading the first line of your reply. I’ll try that approach. Thanks for clarifying Swarfy, id hate to butcher things and cause damage. The quality and design of these i find truly beautiful. It’s testament to while there still functioning after all these years.
I’ll reply with my results when I give it a go later.
Thanks again
Alex
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Et voilà. Thanks again swarfy. Saved me struggling.
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Thanks for the accolade. That was easy.
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Hopefully one day I will have the privilege of passing on the knowledge *thanks*
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Speaking of the shifting quadrant pivot pin, can anyone say if it is OK for the pin to pivot in the inner cover rather than the quadrant pivoting on the pin? My $100 swap-meet gearbox was beautiful inside, except, it must have been sitting for 30 years when I bought it several years ago and the oil had basically turned to asphalt. Got it out of everywhere except the shifting quadrant. Pin pivots fine in the casting but not the quadrant on the pin. I'm dragging my feet on pressing out the bushing to pull the pin.
Richard L.
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Richard,
Try heating the casing around the pin; then let it cool. Do this several times, then heat once more and try jacking out with a 1/4" BSC bolt.
Richard Too
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From a geometric perspective the axis of rotation will be the same and the selector mechanism will work. Alas the bearing surfaces are now the soft alloy casing and the harder pin. Short term, well. OK, but for serious use better to warm things up and extract the parts. Loctite the pin to the alloy on reassembly as an aid to keeping it fixed in place, assuming that the pin location is not too worn and the casting can be retained for further use.
Swarfy.
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taking into account how far it all moves a nice shiny hardened pin moving in the large area that it does shouldn't hurt anything. didn't the japanese have camshafts revving away in bare ally heads for thousands of miles
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True, and on some Enfields the ally conrod rode directly on the big end journal, but they were force fed oil.
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True, and on some Enfields the ally conrod rode directly on the big end journal, but they were force fed oil.
...as do Thunder Engineering billet rods with no force feeding (noting that the inner gearbox cover ain't no billet).
Richard L.
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Richard it's not doing much work, my pin pivots in the ally and no problem. it always has.
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Berger,
I'm giving the whole thing a soak in penetrating oil in hope of loosening the tar, so movement of quadrant on the pin would be about the same as pin in the alloy. I'm guessing this is about like original design, since there is no set screw and it doesnt seem to be a press fit.
Planning to be in line when the pubs/bars finally reopen. *smile*
Richard L.
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I think you will have to take the bush out and pull the pin out then once it's all cleaned up dab a bit of Loctite on it, over here our pubs are shut and my local has just been knocked down *eek* *pull hair out* *bash*
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...my local has just been knocked down *eek* *pull hair out* *bash*
Saddest news I've had in the last five minutes. *smile* (Actually, probably is a shame.)
Richard L.
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Not planning to pull the pin out often, but the Loctite raises an issue. The pin has to be extracted by pulling on an inserted screw. I think it will take heat to get Loctite over that much surface area to release while the pin is pulled. Not insurmountable, just a point.
Richard L.
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Hi All
Not planning to pull the pin out often
*eek* *eek*
John
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Not planning to pull the pin out often, but the Loctite raises an issue. The pin has to be extracted by pulling on an inserted screw. I think it will take heat to get Loctite over that much surface area to release while the pin is pulled. Not insurmountable, just a point.
Richard L.
Forget the loctite , It will only cause more grief in the future. The floating pin will outlast all of us.
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Not planning to pull the pin out often, but the Loctite raises an issue. The pin has to be extracted by pulling on an inserted screw. I think it will take heat to get Loctite over that much surface area to release while the pin is pulled. Not insurmountable, just a point.
Richard L.
Forget the loctite , It will only cause more grief in the future. The floating pin will outlast all of us.
I agree, but I am going the free the quadrant from being tarred onto the pin so that it can move at least as freely on the pin as the pin moves in the alloy.
Apologies to everyone for taking so long to get to it, such that the issue has lingered longer than it maybe deserves. I've been otherwise busy.
Richatd L.
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Done and done (with this bit, at least).
Shift lever bush pressed out without a problem using my cheap-ass arbor press and a little heat. To my surprise, shifter quadrant pin pulled right out without being stuck in the quadrant. Just sticky. Polished the pin, and a very light hone on the inside of the quadrant, and no more sticky.
The one thing I did here which amused me, because I hadn't tried before, was to roll up a piece of sandpaper and chuck it into the drill press. Worked fine for a light hone on this small ID hole..
Richard L.
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True, and on some Enfields the ally conrod rode directly on the big end journal, but they were force fed oil.
Not actually the case as there is a floating white metal bush in the RE big end.
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Maybe not the Enfield, but some engines do actually run the alloy conrod directly onto the crankpin - Seagull outboard springs to mind.