gearbox leak

Hi Norton braintrust, I developed a leak from my mk 3 gearbox whilst its on the sidestand. Its comming from the threaded hole where the selctor fork rod threads into to main housing. The threads were a little suspect (I noticed that when I rebuilt the gearbox) but opted to loctite it in hopes that it would be ok since the rod is located on the other end by the inner housing. Obviously that didnt work. problem is that I cannot tighten it down too much or the threads will strip out completely. I figured that I would have to helcoil it (3/8 - 20 bsf) what do you think? If that is the solution how should I locate the hole (I have a machine shop). I was thinking I would put on the inner cover and secure the housing to the mill table on the flat end where the cs sprocket goes on and then locate the hole off the inner cover.

thanks


mark

You need to use some form of gasket sealant on the clean, dry threads, as the selector fork rod is held captive by the gearbox inner cover anyway, so there's no need to do it up very tight, (in earlier Norton 'laydown' boxes the rod is only a push fit). And check that you are not over-filling the gearbox.

L.A.B. said:

You need to use some form of gasket sealant on the clean, dry threads, as the selector fork rod is held captive by the gearbox inner cover anyway, so there's no need to do it up very tight, (in earlier Norton 'laydown' boxes the rod is only a push fit). And check that you are not over-filling the gearbox.

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thanks as always L.A.B

what do you think about yamabond on the threads (before I only put it on the outside)

or teflon tape?


thanks

Mark

I expect Yamabond will be fine, although I've never used it.