How far to screw it in?

[SandPebbles]

I am rebuilding the gear box on my '74 3C and last night I was installing the detent arm and
spring (a new spring from Wolfgang!).  I installed the hex head cap screw, with lock nut
into the threaded hole in the casing.  If I install the screw so the end is flush with the outer edge
of the case, therefore using all the threads, the screw appears a bit short and the spring pulls on
the detent arm at an angle.  The detent arm is not only pulled up but also a little bit outboard to
the left.

If I install the screw in a position to have a fairly straight pull on the spring, all the threads in the
case are not engaged by the screw. 

Neither of these scenarios is perfect.  I though about getting a longer hex head cap screw but
I believe these are the original parts and am curious how they should be installed.  I am getting
ready to button up the cases and do not want to have a failure in these parts.
Any thoughts would be great!

Keith

 

[mcnicol]

Keith, since none of the "heavies" have responded yet, here's my two cents worth. My Jota is still in bits so I looked at the dismantling photos. The M6 bolt that the spring attaches to was screwed into the hole in the casting just far enough for the detente return spring to have a straight run i.e. no side loading, so it definitely wasn't screwed all the way into the threaded hole. Probably screws in a bit over 10mm, more than enough since the only loading on it is that piddling little spring.
Does remind me though that I need to buy a new one for when I start putting mine back together. Having to haul the motor out and split the cases to replace that tiny little spring was a really bad idea on the factory's part, good thing they fixed it on the series 2 motors.

Ken

 

[SandPebbles]

Ken, 

Thanks for the reply.  Yes, I was watching my post move down the pecking order in "Technical" with no
responses and thought maybe I asked a stupid question.  Yet as I read through the forum, there seems to
be no component of a Laverda that has not been fully scrutinized.

I too looked back a my disassembly pictures for help.  As I also search my memory, I may recall thinking
that M6 bolt was not fully threaded in when I took apart the gearbox (heck, sometimes I forget what I
ate for breakfast!). 

So, I have tried to find a happy medium between thread engagement and side load on the detent lever.
I was wondering if fitting a longer bolt was a common upgrade among the Laverda specialists on the
forum.  Thanks again Ken and good luck with the Jota!

Keith

 

[CLEMTOG]

having the spring at precisely 90 degrees to the bolt is not an issue,tha is just getting too anal, the spring has "hooked rounded" ends and can take a lot of out of square punishment.I always install the bolt to its full depth of the casing and then lock up the nut, I also clean it scrupulously with brake cleaner, or even meths and add a  dollop of loctite on the bolt and the nut, all it is doing is ensuring a bit of feel as the drum turns and engages in the roller.

The question you have to ask yourself is this
is the original, years old, spring a better bet than the aftermarket pattern part that you will install instead? I have never seen one broken yet, but they do, and frequently at an inconveniant time
CLEM