Brennan:
I believe the most common place is the area around the lower frame to transaxle bolts. Someplace there were some pictures of somebody's repair on this, but I can't find 'em tonight......Kraig???
As far as problems with the NF's, I'd read all of the FAQs, you'll soon get the picture of where the problems on Cubs are, and most of 'em apply to both NF and WF tractors.. There are literally thousands of these machines still out there both mowing and pulling (just scroll back trough some of the pics to see as many NF's as WF's in action !)