BSA Owners' Club Forum

The BSA Workshop => Twins => Topic started by: MARKIE2CUPS on 09 May, 2017, 09:00:09

Title: Primary chaincase to crank case assembly
Post by: MARKIE2CUPS on 09 May, 2017, 09:00:09
Hi, just assembling my 1957 A10 golden flash primary chaincase to the crank. My question is are there two gaskets which sandwich the steel spacer disc or just one? If so in what assembly order. Looking at well known website​ states only one for my swing arm version. But I found two old ones in the box of bits that came with the bike.
Thanks
Mark
Title: Re: Primary chaincase to crank case assembly
Post by: TTJOHN on 09 May, 2017, 09:18:28
Mark.
Just the one gasket  is needed between the crank case and the primary chain case & there should be four studs to secure this, it is advisable to wire these as there should be drill holes in the studs. HTH

TTJohn
Title: Re: Primary chaincase to crank case assembly
Post by: JulianS on 09 May, 2017, 09:36:51
It is crankcase - gasket - steel spacer - gasket - primary chaincase.

So 2 gaskets 1 steel spacer.

The earlier swinging arm parts books dont agree, the 1954/55 saying only a gasket and the 1956/57 and 1958/59 sayig 1 gasket 1 steel spacer.

What logical reason would there be to have one metal to metal (and probably leaky) joint in that sandwich? I suspect an error in the book.

The 1960/63 parts book shows 2 gaskets and 1 spacer and is shown below.
Title: Re: Primary chaincase to crank case assembly
Post by: MARKIE2CUPS on 10 May, 2017, 09:06:58
Thanks for the replies much appreciated. Have another gasket on way. My parts book doesn't show any gaskets at all just the spacer. I'm going on the logic of any metal meeting surfaces must be sealed if oil is involved. I'll also certainly wire the bolts
Thanks again
Mark