John Deere does not offer any disk implements for the subject model. Any feedback on the inherent risks of overheating, transmission strain, or stress on the frame, etc. by using the tilling disk shown would be appreciated.
Oliver Super55, John Deere 4310, John Deere 4400, Kubota L2500 (had),
Your 970 will handle that disc harrow fine. Being that the 970 is a gear drive it is actually much better suited for drawbar work (ie. pulling) then similar sized hydrostatics.
There's a little bit of a learning curve but you'll quickly find what gear/range will work best for your tractor and type of soil.
As long as the clutch is is good shape there should be zero issues. When you do sharp turns make sure the disc is lifted out of the soil or you'll have lateral stress on the rear axle mounting points and just keep an eye on the temp.
Even though I have 3 JD with more horsepower I always use my old Oliver Super 55 for discing just because IMO the gear transmission is superior to the hydro at doing this task.