500 gearbox shift drum guide - modification ?

[McCabe-Thiele (Ted)]

I thought I had mislaid the shift drum guide  spring & ball even though I'm pretty sure mine did not have either.
Looking in the manual it looks like they modified the system for some reason.
Only one selector drum is listed that strikes me as strange as there are two designs of drum guide.

Should I be looking at changing anything whilst it is still in bits?

[Oddjob]

Only the very early engines got the ball and spring Ted, the rest got a modified bolt which has a lug? on the bottom, a collar goes around this lug. You're almost certain to have that system.

[mickwinf]

Ted I had the same thought when I assembled the gearbox on Lazarus. The shifter drum part number is the same as the old 350k and never changed, the indent for the ball is still there but the neutral stop position is sorted at the clutch end. the collar stops any lateral movement.

[McCabe-Thiele (Ted)]

TBH Mick I find the gearbox neutral point weird - on the 400 there was the indent for the neutral switch so you knew where you were.

On the 500 I have no idea what part of the drum end  should be pointing in.
I'm awaiting the new bearing half clip retaining rings from DS so have been looking at where neutral should be - I suspect its around 7 o clock mark  looking at the drum end indent.

[Bryanj]

Its where the indent is at the bottom of the hole the retaining bolt is in as the spring and ball were in the centre of the original bolt