Hi all,

I'm finally at the stage where I can almost fit my rebuilt (rod change) gearbox to the motor, and I thought I would make sure I can select all the gears properly just by sticking a screwdriver in the selector shaft. Almost everything seems to work, but after I've pushed in the selector shaft to select 4th I can push it in a bit further (and it stays there rather than just springing back), and this causes the 3rd/4th selector hub to move past where it's meant to be and touch the laygear. If that makes sense...

Is this normal, and does the external linkage stuff stop not allow this to happen, or is something in the gearbox not right?

Cheers,
Harry

Do you have the diff housing on and the side covers fitted?
The detent ball & spring behind the RH cover holds it in position for each gear.

It is said if you keep your hand on the gearlever this can wear the selector forks, IMO this applies more to these rodchange boxes than to the magic wand and remote boxes. Both those have hard stops to limit selector shaft travel, but it's still a good idea.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Yeah I've got the side covers fitted. I would have thought the detent ball and spring only make sure each gear is either fully engaged or disengaged though, rather than limiting the total range of movement of the selector shaft?

My understanding is that the rod change has a little overthrow. The detent under the diff side plate then holds the selector fork in the right place. When in gear the detents in the selector hub hold it in the correct position. It should not stay in the overthrow position. Once it is in gear, it should stay there, without load on the selector fork.

There is a bit of overtravel in a rodchange box, it is part of BL's (agricultural) design.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Actually Doc, the Wand and Remote Shift Boxes do have (and must have) over-shoot to work (look in the black book, pp f-6, 'Selector Shafts').

I've seen selector forks wear just as bad in all types of gearboxes. It is a little worse in a Moke and any Wand Gearbox as the gearstick always leans back, putting constant pressure on the 2nd and 4th gear sides of them. It's not so bad in a mini (as the gearstick is almost up-right), but traveling with hand on stick will kill any of them.

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