1952 A7 plunger layshaft thrust washer

[anjimehra]

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

[duTch]

 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...

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.

[Topdad]

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, cheers Bob

[duTch]

 
   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...!!!
                                                                                                                   

[edboy]

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.

[anjimehra]

 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...

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

[anjimehra]

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.