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AMC Box timing

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AMC Box timing

Posted by robert_tuck at August 07. 2017

After taking my box apart (several times!) I can't get the timing between the Quadrant and camplate, Getting my aged back down enough and in the gloomy interior of the box its hard to see 2 teeth align with the track, is there a better way?. At certain points the quadrant and camplate rub against each other too , maybe just because they are not timed right , but does not seem right either.

Re: AMC Box timing

Posted by robert_tuck at August 07. 2017

Panic over,  Old brits site to the rescue,  leave all the gears out,fit the inner cover and check the action and clearance to the inner cover slot .  then fit all the gubbins.  The stress of getting 3 old bikes sorted and a van , all with multiple issues is fogging the brain.

Re: AMC Box timing

Posted by anna jeannette Dixon at August 07. 2017
Previously robert_tuck wrote:

After taking my box apart (several times!) I can't get the timing between the Quadrant and camplate, Getting my aged back down enough and in the gloomy interior of the box its hard to see 2 teeth align with the track, is there a better way?. At certain points the quadrant and camplate rub against each other too , maybe just because they are not timed right , but does not seem right either.

Hello ROBERT   now try this out  undo the short bolt that holds the selector cam plate in the gearbox  and remove all the main shaft gears but fourth   then fit the third gear and it dog refit the shaft that holds the dog selector  refit second and first gears  and this selector dog   refit inner cover with the sector arm in fourth gear the arm should be looking up Ward  then make sure the selector cam plate is in fourth gear to mate up the the selector arm you may have to do some judging so the teeth mate up right you can push out the cam plate so then mate up so it in fourth gear    when you have done this now with two nuts fitted on you can move the main shaft and try going down the gear box for fourth to third then second the neutral and first  then go back to second and fit the rest of the nuts and then the outer cover  do up the screws  and then you can move the gear lever back to neutral  the then first and up the gearbox while moving the main shaft around  so you get all gears selecting right    and refit bolt  for the cam plate do make sure the ball and spring for the cam plate is working ok   when filling with gear oil high poly 80  take out the small bolt in the out cover at the back of where the kick start is   and fill with oil until oil runs for this bolt hole   that your oil level replace the bolt  and fit inspection plate  with the two screws   now have fun   yours  anna j      

Re: AMC Box timing

Posted by Colin Peterson at August 07. 2017

Just by-the-by, I find that the undisturbed oil level screw makes an excellent level mark when putting oil into the gearbox via the inspection cover! Wink

Re: AMC Box timing

Posted by anna jeannette Dixon at August 07. 2017
Previously Colin Peterson wrote:

Just by-the-by, I find that the undisturbed oil level screw makes an excellent level mark when putting oil into the gearbox via the inspection cover! Wink

hello yes that right I forgot this one  but hoped he knew where to fill the gearbox from   have fun    yours anna j

Re: AMC Box timing

Posted by Colin Peterson at August 07. 2017

I forget stuff all the time! It's a funny one though, all the manuals say to add oil until it runs out the level hole, but leaving the screw in saves clearing up the mess. They might just as well have moulded in a level marker, and saved a few pennies in the manufacturing – unless I'm missing something ...

Re: AMC Box timing

Posted by anna jeannette Dixon at August 07. 2017
Previously Colin Peterson wrote:

I forget stuff all the time! It's a funny one though, all the manuals say to add oil until it runs out the level hole, but leaving the screw in saves clearing up the mess. They might just as well have moulded in a level marker, and saved a few pennies in the manufacturing – unless I'm missing something ...

hello yes your brain in over drive and thinking too much  now sit back with a nice cup of tea and a biscuit and realacks  with classic FM  and put brain to rest  have fun yours  anna j  

Re: AMC Box timing

Posted by Colin Peterson at August 07. 2017
Previously anna jeannette Dixon wrote:
hello yes your brain in over drive and thinking too much  now sit back with a nice cup of tea and a biscuit and realacks  with classic FM  and put brain to rest  have fun yours  anna j  
Haha yes too true, thanks anna j!

Re: AMC Box timing

Posted by robert_tuck at August 08. 2017

Well! ,I'm still in no-mans land.  A jam going in or out of third once the inner cover on, it will select but only after wheel turning and force. With the gears out, the box goes thro the selection perfectly also with just the inner cover on ,so the timing is ok. All parts look good,no wear or bent selectors.  The only thing That I'm unsure of is the mainshaft which I have not had out has about 5mm free end float (with the loose gears and covers off)  ,I would have thought the final drive sprocket etc would have fixed it more. Any ideas before I go back to a push bike and stabilizers??.

Re: AMC Box timing

Posted by john_holmes at August 08. 2017

The wheel will need turning as there are very few static conditions all 4 gears are available if any, but the force required for selecting each gear should be the same.

Re: AMC Box timing

Posted by robert_tuck at August 08. 2017

Hi John, Yes I would expect to have to turn the back wheel (its jacked up for that)  Just don't know why it should be so stiff , It rode like that too ,took ages to unlock and allow 3rd in or out.The problem is there with the gears in but without the covers on too,so its not the  pawl or springs. Could do with one of those minaturised men to get right in there where the action is!!. Can't see anything wrong with the camplate tracks or plunger.

Re: AMC Box timing

Posted by john_holmes at August 08. 2017

It has to be related to the inner cover or something that the inner cover is resting on or touching, that's both shafts of course. Have you looked at the Gearbox pdf which has been posted a couple of times, it shows you the parts that move for each gear change and it allows you to isolate the 2 to 3 and 3 to 4 moving parts, these and the 2 shafts must be the prime culprits especially any common to both gear changes.

The other option is to only fit the gears and parts for 4th, 3rd and 2nd and see if anything improves by then taking further parts out one at a time.

For my BSA Unit singles I have a spare scrap timing side crankcase with a window cut in it to see what's going on inside the gearbox, a scrap AMC box could be used in the same way.

Re: AMC Box timing

Posted by robert_tuck at August 08. 2017

Finally got it back together and selecting all gears, no road test yet. It has been said there is a degree of black magic in getting one to work well, I would not  have believed that for an instant. However 3 more stripdowns with 4 different manuals?references to hand ,it is now cooperating ,  no idea why!!,  on the one before last ,the layshaft endfloat (so carefully set up with Dial guage etc )  dissapeared ,so it was back to bits remove shims ,loads of end float,who cares, it works.I would not have minded but I have rebuilt 4 or 5 of these boxes no problem.  Never again,without a witch doctor assisting.

Re: AMC Box timing

Posted by anna jeannette Dixon at August 09. 2017

hello well you can give me a ring at any time  my phone number is 01430 430831   mostly around after 4 pm   as I work a 3 day a week  has us over 60s do in our days    and there should be a bronze spacer between four and third its does get worn over time   now ride carefully and have fun   Yours Anna J  

Re: AMC Box timing

Posted by robert_tuck at August 10. 2017

Hi Anna,  thanks but members of the local covern have offered spiritual guidance if I go there again,  Don't think there is a bronze spacer but the end of the bush if damaged can snag on the shaft spline. A test ride has been ok,  that only leaves 2 bikes and a van to sort in the next week.

Re: AMC Box timing

Posted by ian_richtsteig at August 10. 2017

Previously anna jeannette Dixon wrote:

hello well you can give me a ring at any time  my phone number is 01430 430831   mostly around after 4 pm   as I work a 3 day a week  has us over 60s do in our days    and there should be a bronze spacer between four and third its does get worn over time   now ride carefully and have fun   Yours Anna J

Hello Anna,

Sorry but there is definitely NO bronze thrust washer in an AMC gearbox as there is in a dollshead or laydown box.   The end of the mainshaft is threaded to allow a nut to tighten against the small mainshaft bearing.  This gives much better operation of the clutch.

The AMC gearbox also has the roller bearings and hardened thrust washer in the sleeve gear deleted.

Re: AMC Box timing

Posted by anna jeannette Dixon at August 10. 2017
Previously ian_richtsteig wrote:

Previously anna jeannette Dixon wrote:

hello well you can give me a ring at any time  my phone number is 01430 430831   mostly around after 4 pm   as I work a 3 day a week  has us over 60s do in our days    and there should be a bronze spacer between four and third its does get worn over time   now ride carefully and have fun   Yours Anna J

Hello Anna,

Sorry but there is definitely NO bronze thrust washer in an AMC gearbox as there is in a dollshead or laydown box.   The end of the mainshaft is threaded to allow a nut to tighten against the small mainshaft bearing.  This gives much better operation of the clutch.

The AMC gearbox also has the roller bearings and hardened thrust washer in the sleeve gear deleted.

 

Hello well my Norton Manxman 650 built December 1960 has a bronze bush in between the third and fourth gears and has bronze sleeve bearings in the gears,  My 1954 Norton Dominator model 88 has the roller bearings in the sleeve gear on fourth gear within a bronze housing and a bronze bush to in-between third and fourth gears. And this gear cluster  is a semi close ratio from an international  race bike  it's a higher gear ratio to normal  now do have fun and be careful when out riding    yours   anna j
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