2005 Ford Escape tone rings---abs sensing

I have had the tone rings replaced on this vehicle at 36,000 and 40, 500. Now, I think one of them is bad again! The abs light came on again and said service brakes/service 4x4 system. that is what it did before when they were bad. I found out that this is a common problem with these vehicles. Is there anyway to stop this problem.. I read on the internet that one guy fixed his with gorilla glue and another had his welded. The part costs about $37 , but the ford comapny has charged me almost $400 on two separate occasions to fix this problem. I can't afford to keep shelling out that kind of money, because ford made a cheap product. any ideas of how I can stop this problem?