Kubota B2782 snowblower destroys its chain after every use! Help!

[87mark7lsc]

Ok everyone. We replaced every part (sprockets, bearings, small shaft the pto connects onto, housing and a new chain. Didn't change anything. Chain still goes from loose and then tight and binds when you spin it. I put my dial indicator on the shaft that runs the gearbox and it has .07 inch runout when turned. Does that mean my shaft is bent? When I put the indicator on the hub of the big sprocket it reads .15 inches of runout. I'm assuming that at the outer teeth area that I would have even more runout than that?

 

[Baby Grand]

Sodo.....excellent write up and explanation...I learned something today...Thanks

Me too - that was a great explanation of a not so obvious failure mode.

 

[Baby Grand]

Ok everyone. We replaced every part (sprockets, bearings, small shaft the pto connects onto, housing and a new chain. Didn't change anything. Chain still goes from loose and then tight and binds when you spin it. I put my dial indicator on the shaft that runs the gearbox and it has .07 inch runout when turned. Does that mean my shaft is bent? When I put the indicator on the hub of the big sprocket it reads .15 inches of runout. I'm assuming that at the outer teeth area that I would have even more runout than that?

Yes, that sounds like either a bent shaft or a trashed bearing.

 

[2458n]

Got to be shaft, bearings would not present binding at the same place because the bearing would spin and present binding at different revolutions. Thinking out loud. With the gear wear can you flip the sprocket so elonnnnnngation occurs against the teeth differently?

 

[Sodo]

You said it was a new chain but wondering if the chain has frozen links, or maybe defective. Was the chain slacked such that chain tension cannot possibly affect your runout measurements? Or does this shaft have that measured runout with the chain removed?

 

[ericher69]

Got to be shaft, bearings would not present binding at the same place because the bearing would spin and present binding at different revolutions. Thinking out loud. With the gear wear can you flip the sprocket so elonnnnnngation occurs against the teeth differently?

when I read the first post I thought right away bent shaft!

Sent from my iPhone 5s 64Gb using TractorByNet

 

[CDN Farm Boy]

Have you also checked the sprocket on the auger shaft for runout? Possible either off-center sprocket or bent auger shaft?

Chain oil is much tackier than other types of oil to resist flying off from centrifugal force.

 

[BAP]

Can you post some pictures? It might help. Another thing you could try that might work for the short term would be to find some #50H chain instead of #50 chain. The H stands for heavy duty version of the #50 size chain. It sounds like you have another problem which ultimately needs to be corrected.

 

[CalG]

Adjust the chain slack at the Tightest part. Only run a chain with enough tension to keep it on the sprocket!

Your woes are from TOO TIGHT!

Even a worn chain/ sprocket combination will survive many hours if the the run is not TOO TIGHT!

Take a look!

 

[87mark7lsc]