Text only | Text with Images

BSA Owners' Club Workshop Discussions

The BSA Workshop => Twins => Topic started by: rightfoot_shifter on 24 Mar, 2018, 07:59

Title: Pre-unit gearbox sprocket nut
Post by: rightfoot_shifter on 24 Mar, 2018, 07:59
Hi Guys
I have a couple of questions concerning the ringnut that secures the gearbox sprocket.
Firstly can anyone confirm the thread form eg TPI?
Secondly has anyone had problems with the SRM replacement part (st stl hex with built-in seal) fitting their sleeve gear; what was the problem and what did you do about it?

Cheers
Russ
Title: Re: Pre-unit gearbox sprocket nut
Post by: AWJDThumper on 24 Mar, 2018, 09:12
I believe the nut is 1 3/16" x 24 TPI; essentially, a BSC thread.
Title: Re: Pre-unit gearbox sprocket nut
Post by: JulianS on 24 Mar, 2018, 09:37
I fitted an SRM sprocket nut to my A10 some years back. The thread form was perfect, however the seal was quite tight on the gearshaft when first assembled. A worthwhile modification, stopping the oil seeping along the sleeve gear bshes and allowing proper tightening ofthe nut.

If you are having a problem with the nut suggest phone SRM and discuss.
Text only | Text with Images