MK3 shifting

seattle##gs · Wednesday at 8:53 PM

I couldn't find the round ball that does the shifting in the gearbox so I substituted the barrel shaped one. The trans shifted just fine using the screwdriver method but when I installed the primary cover and tried shifting from the left side it would not budge. My question is: is the round ball mandatory in the MK3 or is something else going on? I jacked up the rear wheel and rolled it back and forth but could not free up the shifting. Once I removed the outer GB cover it shifted again easily with a screwdriver.

Torontonian · Wednesday at 9:34 PM

Dunno. I use the stock ball in both my MK 111's .

L.A.B. · Wednesday at 9:36 PM

seattle##gs said:
My question is: is the round ball mandatory in the MK3 or is something else going on?

Yes because the shift mechanism is angled in the outer gearbox case on the Mk3 (so the crossover shaft clears the gearbox casting and that has a shortened quadrant boss and quadrant shaft which is held in place by a circlip instead of a bolt) .

stanthomas · 2026-09-10T04:59:56-0600

Actually, I think it's more that the cross-over shaft has to clear the clutch drum. But the reason the knuckle pin roller is ball shaped is the same: the shaft is at an angle and, as the the quadrant moves, the roller doesn't just rotate vertically and slide horizontally, the angle of entry of the ratchet pin changes too so the roller need to rotate horizontally as well.

L.A.B. · 2026-09-10T05:37:05-0600

stanthomas said:
Actually, I think it's more that the cross-over shaft has to clear the clutch drum.

And that but the mechanism must still clear the gearbox case at the gearbox end in the first place.

seattle##gs · 2026-09-10T09:01:44-0600

OK. Fortunately the ball showed up in my searching so I can replace the roller.
Going the other way, using the ball in a pre-MK3 doesn't seem to offer any advantage other than being able to install it with the inner cover in place.
Thanks for the info.

stanthomas · 2026-09-10T15:58:28-0600

L.A.B. said:
And that but the mechanism must still clear the gearbox case at the gearbox end in the first place.

I would suggest that, with the shortened shaft of the quadrant, there is sufficient clearance for the cross-over shaft to exit square.

stanthomas · 2026-09-10T16:01:33-0600

seattle##gs said:
Going the other way, using the ball in a pre-MK3 doesn't seem to offer any advantage other than being able to install it with the inner cover in place.

Correct, although it is kinda handy when you forget the put the roller in doing a late night rebuild.

seattle##gs · 2026-09-10T20:16:05-0600

stanthomas said:
Correct, although it is kinda handy when you forget the put the roller in doing a late night rebuild.

has happened many times

MK3 shifting

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