hairline crack in tranny case, opinions please

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openroad

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Looked close and found a crack from the sleeve gear bearing to the layshaft, I can't see up in the layshaft pocket but certainly can't feel any of this by touch.
Sorry for the big pictures.
Does this crack mean my case is doomed?
hairline crack in tranny case, opinions please

hairline crack in tranny case, opinions please
 
Not at all. You have the infamous "taint crack" that's currently being mulled over in another thread. As far as I know, your box is usable as long as the crack doesn't extend to the outside of the case and cause lubricant leakage.
 
I replaced mine which had this same crack. I was concerned it could spread and ultimately lead to something more undesirable like the case splitting in two or dumping its oil or both or similar!

Has this ever happened? Can / do these cracks develop into more serious failures?
 
No reason for concern, I noticed this crack in my gearbox twenty years ago, and it is still ok, and this crack has not progressed over the years.
Many gearboxes seem to have developped a crack at this spot, and I am not aware of any serious cconcequences.
 
Mine had a loose sleeve gear outer bearing which i attributed to this crack. I loctited it in but it didn't last. I'm fitting an alton starter and noticed i could move the gearbox sprocket back and fourth. Not good. I've bought a new shell from rgm.
Having said that, if both your bearings are a tight fit in the case, i wouldn't worry about it.
Terry
 
Both really tight, took a bunch of heat to make em go in. Or maybe a bunch of time to get it to heat up, ....used my weed burner for a torch!
 
If you want to have peace of mind about the sleeve gear bearing not becoming loose, this is the time to lock it mechanically.
There are some posts here dealing with it.
 
This starts out talking about different gearbox P/Ns possibly alluding to stronger cases, morphing onto the infamous Portuguese layshaft bearing, and also hits on the taint crack about half way through the thread. gearbox-info-t26323.html#p348382

Nathan
 
Peter R said:
No reason for concern, I noticed this crack in my gearbox twenty years ago, and it is still ok, and this crack has not progressed over the years.
Many gearboxes seem to have developped a crack at this spot, and I am not aware of any serious cconcequences.
Click to expand...


I too ignored this crack and you do so at your very great peril. The crack in my machine split the bike in two. While travelling at significant speed, no less, and the oil and gas caught fire from the catastrophic sparking. The fire department was called, trucks were sent, great delays in traffic followed. Flights were missed, subsequent UN meetings adjourned and total global pandemonium ensued ... .
 
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