I've also had trouble with aftermarket front LCAs. Mine were from Agent 47. The set up I got was their "track" version, which I think is now their only version of their SLA.
These arms on the S197 seem to be under far more stress than the aftermarket anticipated (or had prior experience with). At least A47's design wasn't fighting to protect a curved tube, it's all straight inputs. Here it is out of the box:
In my case, I had weld failure as well as an enlarged mounting point where the rear strut bolted to the front arm. This happened after only 7-8 weekends.
After discovering this I pulled the arm, ground out the weld and laid down another bead to get me through an event. A47 sent me out revised arms that better reinforced this area (we worked out a deal). However, I also discovered that the hole in the old arms had significantly distorted.
I suspect that this was largely due to several factors, one of which was poor bolt selection. A fully threaded bolt was supplied for this mounting point, and I knew that was a no-no from the start (Carol Smith was whispering in my ear during the install, but I refused to listen). The pics don't really show it, but those threads had (as Smith warned) acted like little biting teeth with every vibration. They simply sawed their way through the metal stock.
On my last outing with them you could feel the front end hunting around under heavy braking, a condition I assume was precipitated by shifting of this point w/in the ovoid area. So anyway when the new arms went on, I used AN bolts w/solid shanks of proper length. Not sure how long they'll last, but it's better than the threaded bolts.
There are many morals to the story, but one that I took away was a renewed appreciation for the engineering and strength that went into the OEM arms.
Best,
-j
