My Sub-frame mount 757 works Great . I to use to be concerned with the issue's people were having with cracked housing's , etc... . Question's I had for them were not answered to my knowledge , Like was it a Geared model or HST model . One area I Think may cause problems with either is How tight people bring up the top link . With My 757 , I Barely put down pressure on the ground using the B.H. bucket and snug up the top link . You can keep putting more and more pressure on the ground and keep tightening up the top link , but I think that is were problems occur as it puts a " Bind " into the 3 point and the tractor housing itself .
I know I read those threads before about people having issue's , Just My opinion on what happened , also , these are compact tractors and Back hoe's , Not full size back hoe's or Excavators , Thus I error to the side of taking my time and not over loading things.
Fred H.