I have Mcleod everthing one my car, and I mean that literally. I just ordered another cable from MM, should be here tomorrow, but tis just getting old.
Check on the quadrant to see for any signs of wear. I broke one and when i replaced it you could see where it was wearing at. I think part of the problem is the cable is slightly angled where it attaches to the quadrant with no support for the cable as it crosses over the 1st and 2nd cable locations.
Not familiar with the McLeod quadrants and adjusters but I know their produacts are usually top notch. There have been issues with the quadrants not being smooth and that causing issues with wearing the cable as djtyau mentioned earlier.
You need to find the root cause of why you are breaking cables. The OEM cable should last 70 thousand miles or more. Does it always break in the same place? If so, WHERE?