Diesel grinders breaking crank shafts

[Wade Judkins]

I am using an Alpine Rhino cutter wheel on my Vermeer SC372 stump grinder with the Yanmar diesel engine and have broke two crankshafts on Reman engine in less than 700hrs of use. Don't know what the answer is. Has anyone else experienced problems like this?

 

[jltrent]

Does it have a slip clutch or shear pin to maybe prevent this?