Author Topic: 1952 A7 plunger layshaft thrust washer  (Read 633 times)

Offline anjimehra

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1952 A7 plunger layshaft thrust washer
« on: 02.06. 2015 05:40 »
Hi guys

Back to pick your brains !
My gearbox came in pieces & minus the lay shaft thrust washer. Can anyone please help with dimensions of this as well as what end float is permissable on the layshaft. Currently it is approx 0.020 " Iam not sure if the blind bush on the layshaft is original & if the collar thickness is correct. Should the float be taken up at the bush end or the front or both ??
The chasis is rolling & the engine mounted.
Thanks
Anji

Offline duTch

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Re: 1952 A7 plunger layshaft thrust washer
« Reply #1 on: 02.06. 2015 09:36 »

 Hi Anji,
 I don't have dimensions at hand, but ID should be shaft size (I think 3/4" 0.750" ? ), OD should be a loose fit inside the dogs of the next gear, and I think *????* 0.093" (?)thick but have seen debate otherwise. Do a search, is part #67-3203

 Couldn't help myself, just did a search here;- http://www.britbike.com/forums/ubbthreads.php?ubb=showflat&Number=341901

 which had this to say, but double check...
Quote
67-3203 Layshaft thrust washer -goes between 1st and 2nd gears, the bevel inner edge goes towards 2nd gear, 1.090" O.D. and 0,085" thick.
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
Australia

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  • bob hebdon
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Re: 1952 A7 plunger layshaft thrust washer
« Reply #2 on: 02.06. 2015 12:03 »
Dutch, I'm nominating you for the job of "plunger g/box " specialist !,When I saw Anji's post I flagged up you to answer it right away, *beer* *yeah* cheers Bob
" rules are made for the guidance of wise men and the blind obediance of fools"
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Offline duTch

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Re: 1952 A7 plunger layshaft thrust washer
« Reply #3 on: 02.06. 2015 18:10 »

  *beer*
   Thanks Bob, that's nice of you , but think I've said before that I know enough to be dangerous, and'm not and don't profess to be any kind of expert, I am only kind of aware of this through my own misdemeanours....and always double check on me...!!!
                                                                                                                   *beer*
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
Australia

Offline edboy

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Re: 1952 A7 plunger layshaft thrust washer
« Reply #4 on: 02.06. 2015 21:10 »
i believe the washer should be just under 2.5mm thick with a generous chamfer on one side [ i machine my own from washers] but assemble all the covers on tight before you do the final build as no endfloat will lock the mainshaft. i ve used two inner gaskets before to cure that problem.

Offline anjimehra

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Re: 1952 A7 plunger layshaft thrust washer
« Reply #5 on: 03.06. 2015 12:45 »

 Hi Anji,
 I don't have dimensions at hand, but ID should be shaft size (I think 3/4" 0.750" ? ), OD should be a loose fit inside the dogs of the next gear, and I think *????* 0.093" (?)thick but have seen debate otherwise. Do a search, is part #67-3203

 Couldn't help myself, just did a search here;- http://www.britbike.com/forums/ubbthreads.php?ubb=showflat&Number=341901

 which had this to say, but double check...
Quote
67-3203 Layshaft thrust washer -goes between 1st and 2nd gears, the bevel inner edge goes towards 2nd gear, 1.090" O.D. and 0,085" thick.

Thanks duTch
Internets been down last 4 days. Will start the research as suggested by you. Will keep you updated

Offline anjimehra

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Re: 1952 A7 plunger layshaft thrust washer
« Reply #6 on: 03.06. 2015 12:49 »
i believe the washer should be just under 2.5mm thick with a generous chamfer on one side [ i machine my own from washers] but assemble all the covers on tight before you do the final build as no endfloat will lock the mainshaft. i ve used two inner gaskets before to cure that problem.

Thanks edboy. Will measure the actual end float & see how it goes.