classic motorcycle forum

Motorcycle Discussions => British Bikes => Topic started by: nickjaxe on December 28, 2015, 05:49:54 PM

Title: BSA Bantam Gearbox Question.
Post by: nickjaxe on December 28, 2015, 05:49:54 PM
Hi guys...I know my bike is not a vintage bike but you guys are so knowledgeable I thought I would ask.

Its a 4 speed B175 1970.

I am putting the 2 stroke engine back together after fitting new seals and roller bearings.

Got the crank end float spot on with 4" thou end float....but when trying a test assembly before applying on the case sealant.

I found I had no end float on the gearbox shafts...in fact it is ever so slightly putting a pre load on the shfts if I bolt them up...

I can see no way of adjust ment...is this clearance normally pre set...

I am presuming there should be some??

Be grateful for any advice.

Nick.
Title: Re: BSA Bantam Gearbox Question.
Post by: chaterlea25 on December 28, 2015, 06:00:20 PM
HI Nick,
Its likely that one of the replacement bearings is not seated fully home?
or a washer or spacer misplaced ?
HTH
John
Title: Re: BSA Bantam Gearbox Question.
Post by: nickjaxe on December 28, 2015, 07:59:11 PM
Hi John..is there normally some means to adjust end float in these type of gearboxes...its my 1st ever bike...seem odd that its not adjustable but I can see no means of it.

I will looking into your idea.

Nick.
Title: Re: BSA Bantam Gearbox Question.
Post by: mark2 on December 28, 2015, 10:24:11 PM
it is a vintage bike
Title: Re: BSA Bantam Gearbox Question.
Post by: nickjaxe on December 29, 2015, 04:31:53 PM
Its ok now guys...I opened the case again...gave the mainshaft a few whacks with my rubber mallet...also the output gear on the other end...tried it again...hey presto 4 thou end float...

Thanks John.

Nick.
Title: Re: BSA Bantam Gearbox Question.
Post by: john.k on December 30, 2015, 12:47:43 PM
A big hammer always works.Happy New Year .Regards John
Title: Re: BSA Bantam Gearbox Question.
Post by: nickjaxe on December 30, 2015, 03:04:25 PM
All the best John.