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CB400F Engine rebuild
K2-K6:
Difficult, without being there, to accurately feel what it's like.
As Dave mentioned, there's a fair amount of movement in gearboxes but in the right direction. They are after all fairly crude, but effective, by nature of design.
What shouldn't happen is for you to move the gear radially as the teeth would vary in mesh to it's pair, which is not acceptable.
Because of their compact nature, some gears are in effect stabilized by it's neighbouring gear which is moved into "dog" engagement with it. Left in neutral, you can't fully see that support, but of course the gear takes absolutely no torque load until it's in use for that ratio.
Also a straight cut gear imparts no sideways loading to the gear itself, so no inherent drive to push it out of alignment.
To summarise, you shouldn't be able to take one individual gear and move it radially on it's shaft so that it goes away from running concentric. That's worn, but slight wobble will be present for many.
A bit long winded, but hopefully give you a little help to check.
taysidedragon:
--- Quote from: K2-K6 on October 29, 2020, 09:52:36 AM ---Difficult, without being there, to accurately feel what it's like.
As Dave mentioned, there's a fair amount of movement in gearboxes but in the right direction. They are after all fairly crude, but effective, by nature of design.
What shouldn't happen is for you to move the gear radially as the teeth would vary in mesh to it's pair, which is not acceptable.
Because of their compact nature, some gears are in effect stabilized by it's neighbouring gear which is moved into "dog" engagement with it. Left in neutral, you can't fully see that support, but of course the gear takes absolutely no torque load until it's in use for that ratio.
Also a straight cut gear imparts no sideways loading to the gear itself, so no inherent drive to push it out of alignment.
To summarise, you shouldn't be able to take one individual gear and move it radially on it's shaft so that it goes away from running concentric. That's worn, but slight wobble will be present for many.
A bit long winded, but hopefully give you a little help to check.
--- End quote ---
Thanks. There's no noticeable movement radially but I can rock the gear on the shaft, worse on the large 41 tooth gear, but that might seem worse because of the bigger diameter.
I'll try to take a video later.
K2-K6:
There's a consideration too about where the load travels if you want to look while in there.
The "bushed" gears only ever run on their bushes by rotating on the shaft when NOT in use as a ratio. Once you select that gear to use it in drive train then either it or it's neighbouring gear slides to connect via the face dogs. Then the torque passes through the teeth and as far as the dogs, then divert into that paired gear and so onto the gearshaft to give output.
It doesn't much matter with some free play as it'll orient itself on the dog faces once changed, it's initial alignment comes from it's opposing gear, and it, having straight teeth that take out misalignment when spinning together.
If you put it in the gear ratio in question, then look at the load path it'll show this.
taysidedragon:
--- Quote from: K2-K6 on October 29, 2020, 01:59:35 PM ---There's a consideration too about where the load travels if you want to look while in there.
The "bushed" gears only ever run on their bushes by rotating on the shaft when NOT in use as a ratio. Once you select that gear to use it in drive train then either it or it's neighbouring gear slides to connect via the face dogs. Then the torque passes through the teeth and as far as the dogs, then divert into that paired gear and so onto the gearshaft to give output.
It doesn't much matter with some free play as it'll orient itself on the dog faces once changed, it's initial alignment comes from it's opposing gear, and it, having straight teeth that take out misalignment when spinning together.
If you put it in the gear ratio in question, then look at the load path it'll show this.
--- End quote ---
Cheers. Makes sense. 👍
taysidedragon:
Play on countershaft first gear.
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