The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => Gearbox, Clutch, Primary => Topic started by: cus on 31.07. 2011 11:32

Title: jumps out of gear
Post by: cus on 31.07. 2011 11:32

G'day Everyone,
Took the 63 for a good test ride this weekend, timed it at 32 deg.,
& took off into the hills. The bike ran really well until I loaded it up
in 3rd, & it popped out. Went back & fiddled around with the
locator plunger, but made no difference, pretty sure its worn
dogs on third, but open to any other reasons before I strip the
box down. Other question is, if I have to get the dogs re-cut,
will I have to take off the inner primary etc., or can it all be
done from the kickstart side, & leave the main shaft in the box,
haven't had alot of experience with gearboxes, so any advise
appreciated. I have a good machinest/ mechanic that can do
the repair but I want to do all the strip down etc.

regards, Cus

Title: Re: jumps out of gear
Post by: Goldy on 31.07. 2011 15:17

I would look at the selector fork first, make sure it,s in good condition not worn and moves freely and that the spring returns it correctly and that the spindle is not binding. All the best.

Title: Re: jumps out of gear
Post by: muskrat on 01.08. 2011 10:23

Also check the forks have engaged both gears. It can happen that one jumps out as you assemble. I KNOW!!
Cheers

Title: Re: jumps out of gear
Post by: cus on 01.08. 2011 22:49

Will I have to remove the clutch etc. to pull the guts out,
or can the main shaft stay in,

regards, Cus

Title: Re: jumps out of gear
Post by: muskrat on 01.08. 2011 23:12

I'm not 100% sure but I think it can all come out without the mainshaft. You will need to remove the selector fork shaft.
Cheers

Title: Re: jumps out of gear
Post by: trevinoz on 01.08. 2011 23:40

Cus,
          Does it select and stay in 4th?
How are the other gears?
Have a good look at the dogs and the camplate also.
Went to Nabiac swap on Sunday and a bloke had clusters for $80. They didn't last long!
  Trev.

Title: Re: jumps out of gear
Post by: cus on 02.08. 2011 00:01

G'day Trevor,
All the other gears select & stay in fine,
3rd also selects well, but pops out under load,

Cus

Title: Re: jumps out of gear
Post by: cus on 26.08. 2011 05:04

G'day Everyone,
Well, started dismantling the g/box, have outer & inner covers off,
is there a trick to removing the grub screw on the selector shaft
or is the only way to remove both primary cases to gain access,

regards, Cus

Title: Re: jumps out of gear
Post by: cus on 31.08. 2011 23:01

Looks like no magic tool to take out the grub screw with primary cases on,
so it all came off, 1st & 3rd gear lock into each other & both are worn,
was able to get both NOS & going back together now, hopefully allsorted,

regards, cus

Title: Re: jumps out of gear
Post by: t20racerman on 01.09. 2011 07:11

Quote from: cus on 31.08. 2011 23:01

Looks like no magic tool to take out the grub screw with primary cases on,
so it all came off, 1st & 3rd gear lock into each other & both are worn,
was able to get both NOS & going back together now, hopefully allsorted,

regards, cus

Keep us posted. Mine jumps out of second under load at highish revs when giving it a handful (ie overtaking cars...) and it is a real pain in the ***. If you successfully fix yours it will motivate me to do mine!  *smile*

Title: Re: jumps out of gear
Post by: wilko on 01.09. 2011 19:16

No wonder, if that's you doing a wheel stand in your avatar!!

Title: Re: jumps out of gear
Post by: cus on 07.09. 2011 06:19

Yep, all sorted....for now!

Cus