Cb400 Countershaft

[4wDaz]

Hi all, I’m just about to strip the countershaft on a cb400 and noticed that both ends of the shaft have a blanking plug fitted but one appears to have a hole drilled in it, is this hole supposed to be in ? Thanks

[McCabe-Thiele (Ted)]

When you say the countershaft is that the rear most one on which the small front chain drive wheel sits?

Mine are  capped  at each end - no hole - no idea if it matters ?

[4wDaz]

Yes, it is Ted, sometimes referred to as an output shaft. I wonder if it was a modification to get oil into the shaft ? It’s done it no harm as the shaft and gears have no wear on them at all. I’m tempted just to leave it, what do you think ?   

[McCabe-Thiele (Ted)]

Yes, it is Ted, sometimes referred to as an output shaft. I wonder if it was a modification to get oil into the shaft ? It’s done it no harm as the shaft and gears have no wear on them at all. I’m tempted just to leave it, what do you think ?

I'm minded to agree with you but I'm not a mechanical engineer - presumably Honda did it for a reason probably to keep oil on the needle roller ends. I do not know if there are any oil feed holes on the shafts themselves I can't remember when I stripped my shaft.

[4wDaz]

Thanks Ted, I agree Honda blanked it for a reason, I don’t know the consequences of just leaving it, the blanking plugs won’t be available now but I could machine something up as a press fit to go in or maybe just use some sort of sealant instead if its not under too much pressure,  I think I’ll call round a few bike shops and see if any mechanics can advise me

[smoothoperator]

Personally I'd feel uncertain about having something so far off standard in the engine. Ultimately it comes down to budget, I think a second hand shaft from Steve at 400 four bits wouldn't be mega expensive. Last time I looked he had one in stock.

[4wDaz]

Personally I'd feel uncertain about having something so far off standard in the engine. Ultimately it comes down to budget, I think a second hand shaft from Steve at 400 four bits wouldn't be mega expensive. Last time I looked he had one in stock.

Yeah cheers I know what you’re saying, from what I can remember the main shaft and primary shaft are only capped at 1 end so as Ted says Honda did it for a reason. It may have been an old engineers modification years ago, there’s no noticeable wear on anything so who knows 

[TrickyMicky]

Y'know, this might be a stupid pie in the sky suggestion, but back in my irreverent younger days I had owned a couple of CB750's, and the final drive shaft on those had a quill feed to an adjustable outlet on the front sprocket. This enabled you to keep the rear chain lubed using engine oil which was flung out by centrifugal force. Ye gods it was effective and bloody messy! So most riders closed the nozzle completely and lubed the time honoured way.  Just wondered if perhaps Honda, on their wisdom, had ideas of possibly doing the same with the 400, but didn't go ahead. Just a thought!

[4wDaz]

It looks like a bit of a bodge to me rather than a Honda job, the holes not drilled in the centre either. I did have 1 comment about it would have been done to stop any gearbox wine but after hours of googling I can’t find any information about it

[McCabe-Thiele (Ted)]

It looks like a bit of a bodge to me rather than a Honda job, the holes not drilled in the centre either. I did have 1 comment about it would have been done to stop any gearbox wine but after hours of googling I can’t find any information about it

I did wonder if it was caused by someone dismantling the shaft with some sort of weird puller !