Gearbox

[cb550k-aaron]

I disagree Oddjob, the pins are lower than the journal surface and I can see the marks on the journal where the bearing has turned and then gone tight and stopped as the engine heated up and the spun when it has cooled.
Seen this tooo much lately with customers engines, as they have tried to rebuild their own motor and then bring it to me saying, it is jumping out of gear.   

In your opinion Trigger Is the spinning of the bearing the cause for the slipping and eventually the damage?

[Trigger]

Hold on I just get my crystal ball out me tool box 
The pin damage should of been repaired to make sure the bearings did not spin, before it was put together and started up. Short cuts on engine builds always bites back in a big way.

[cb550k-aaron]

Ok let me know what it says  lol.

If I go the route of repairing this casing with the pins in the correct places. Can you give any tips or would u just replace?

[Trigger]

Ok let me know what it says  lol.

If I go the route of repairing this casing with the pins in the correct places. Can you give any tips or would u just replace?

Hard to say without measuring the cases up to find how much damage has been done.

[cb550k-aaron]

Ok let me know what it says  lol.

If I go the route of repairing this casing with the pins in the correct places. Can you give any tips or would u just replace?

Hard to say without measuring the cases up to find how much damage has been done.

Are there readily available specs that it should be? Tbh it hasn't done anymore than 150miles I'd say since the Pins were damaged.

[Trigger]

Yeah your correct Trig, the new pics clearly show the damage, there wasn't enough detail on the original pics for me to be sure.

Is it enough to bin the bottom end though? I'd chance using it again TBH, so long as the pins are made to stand proud of course and a new gearbox is fitted. I'd be interested in where all the debris has gone though, is it in the sump?

The damage to the cases, were the pics taken before or after the rebuild? I'd say after as those breaks look very clean, if that's the case then whoever reassembled the cases is responsible.

I thought your eagle eye would of picked it up from the first picture 

[tom400f]

So for the curious, the gist of this damage is that gross misuse has stripped the teeth of 2nd and 3rd, locked up the free/splined cogs causing the shafts to rotate in their bearing housings and ramming the dowels down into the case where they have tried to exit. Subsequently the blind bearings are free(ish) to rotate as they want?

That's some achievement.

[Green1]

Maybe I should stop bashing mine through the box.

[Trigger]

So for the curious, the gist of this damage is that gross misuse has stripped the teeth of 2nd and 3rd, locked up the free/splined cogs causing the shafts to rotate in their bearing housings and ramming the dowels down into the case where they have tried to exit. Subsequently the blind bearings are free(ish) to rotate as they want?

That's some achievement.

Nope ! Some muppet put the crankcases together without lining up the bearing housings with the pins located. This pushed the pins through the cases, allowing the bearings to spin 

[Green1]

I shall carry on abusing mine then 

[Johnwebley]

you do as you want.
I will continue to ride like a pussycat with sore paws !!!

[Trigger]

you do as you want.
I will continue to ride like a pussycat with sore paws !!!

So will I John, I always let Julie ride like a lunatic 

[Green1]

you do as you want.
I will continue to ride like a pussycat with sore paws !!!

 

[K2-K6]

So for the curious, the gist of this damage is that gross misuse has stripped the teeth of 2nd and 3rd, locked up the free/splined cogs causing the shafts to rotate in their bearing housings and ramming the dowels down into the case where they have tried to exit. Subsequently the blind bearings are free(ish) to rotate as they want?

That's some achievement.

No,  it's the other way round. As Trigger says,  someone has put it together with the bearings not located on the positioning dowel pins,  then torqued up the cases forcing the pins through the casting and allowing the bearings to be something like free to position themselves.

If the gear shafts move in relation to the selector forks,  then it's possible to get two gears try to partly select at the same time. As you come out of second gear it should clear the engagement first and just before it drops the third gear dogs into place ( it's a fine line of synchronisation)  but if the third gear dogs just touch their target while second is still hooked up then the dogs are strong enough to take it. It just fires a couple of teeth off the cogs as they are more fragile / smaller than the dogs. Then the shrapnel goes through other stuff if chunky enough to do damage.

Ironically,  if it was bashed through quickly / brutally from second to third,  then you'd go faster than the conflict would occur so would get away with that situation. But you wouldn't know in the first place,  so moot point.

[tom400f]

I would never imagine someone would not align the pins. Just goes to show, never underestimate the stupid.