I've had my shocker airbag hitchhttp://www.shockerhitch.com/index.php?
pr=Home_Page for close to 8 years now, and it has been a great product, but not long ago, one of the bushings, well started melting
I sent an e-mail asking if this was a common or known issue, the owner of the company quickly replied, asking for pictures, as they had never seen that happen.
So I took and sent them pictures and got a reply pretty fast, asking me for my shipping info, as they were sending me new bushing, no cost, and they had never seen that before, a few days later, the parts were at my house.
A great product if you tow as much as I do and great customer service as well..