CATastrophic 320C failure

[Bosvark Kzn]

So today the swing motor on my Cat 320 disintegrated. Looking at the photo, any theories as to what could have caused this? I suspect a failure in the slew box which caused the slew box internals to push upwards and broke the swing motor housing.

 

[lantraxco]

Or a serious failure in the swing motor causing hydraulic pressure in the gear case?

 

[John C.]

At this point what does it matter? The gear box is ruined and at the least will have to be torn down and assessed for what is left. The motor should also come apart for bearings and seals at the least.