4th Gear Won't Engage

MikeMcCartney

Forum User
VOC Member
Well, here's one for you all. The newly - rehabilitated Black Shadow transmission was fine until a few weeks ago, when it started to experience the following issue: when shifting into 4th, the shift mechanism registered a firm 'click' into gear, however there is no gear engagement and a clicking noise emanates from the tranny, similar but not identical to the noise generated by a missed shift. The engine was rebuilt by an acknowledged expert in the feld, so one may assume with some degree of confidence that the gears, shifting mechanism, etc, are in first - class condition.
The other three gears engage fine, and stay engaged when running. The tranny was fine, engaged firmly in all four gears, up until this started to occur.
Any advice? I've been twiddling with the shifting linkage as per the Rider's Handbook, but to no avail.
Happy motoring, by the way! ... This year has been a lousy one for biking in Toronto, what with rain every day or so; hard, driving rain with lightning, thunder and all the accessories..... Monsoon weather by any other name!
 

mercurycrest

Well Known and Active Forum User
VOC Member
Mike,
If you have "clicking noises" in the gearbox, I'd suggest you take a look inside. A locked up gearbox is no fun, especially if you're at speed, in traffic.
Cheers, John
 

john998

Well Known and Active Forum User
VOC Member
4th gear

Hello, A common problem with the twin gearbox is marginal engagement of 4th gear. On my box I had to move G6 constant mesh pinion to get sufficient engagement.
It would appear unlikely that it is this problem as it usually shows up after the dogs get worn.
It would be a good idea to have a look in the box, if you cannot engage top using the gear indicator.
One possibility is that the clutch shaft bearing has moved out in G2 due to the lock ring unscrewing. John.
 

bmetcalf

Well Known and Active Forum User
VOC Member
G/B

Fiddling with the G57 eccentric per the Instruction Sheets may help, also make sure the G80 nuts on the battery platform tube are adjusted right.

What a bike! The battery platform affects the gearbox shifting. No wonder we are such chick magnets!:D
 

Don Morris

Active Forum User
VOC Member
It could be other problems but I agree with john998. The engagement can be only just enough and it has caused the shifter fork to burn out due to endthrust, particulary when dogs are worn.

I measured the endfloat of the clutch shaft - dog end on with dog - when the box is in neutral, took something away for clearance and sized the spacer to suit. I even hand ground something off the output shaft to enable the clutch shaft to enter the gearbox more.

It could be that pesky split pin but as said gearboxes should be as 100% certain as to being correct, a gearbox seizing up is no-no.
 
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