What would cause timing belt to shred and seize engine

2.7L Full timing components kit belt pulleys and water pump

*IF that's the case* - the repair shop owner will have to 'prove' it was your fault that the belt failed within 6,000 miles .. In court if necessary!! (Round up all the paper work) .. Did you even get some sort of explanation as to how it is YOUR fault?

No

IF you have the dated repair bill with the mileage , take it to small claims court if that is what it takes! .. You should give the repair shop one more opportunity to resolve this problem first.... Good luck!

I had the belt replaced by lithia at 123000 miles and shredded at 129000 miles and locked engine up and they told me it was my fault because the tensioner and waterpump that was replaced at the same time as the belt was not the cause.

I think there are several questions needing resolution before going to small claims. Who diagnosed the belt failure and did they cite a cause? Was the repair shop who completed the original work licensed and is there an invoice? Has the original repair facility inspected the vehicle? Also, exactly why (reason) do they not believe it is their responsibility? Some shops only have 90 day warranty periods...even then a reputable shop will address the problem. Any repair facility should provide detail of their position in a matter like this...new parts do fail and even the best Technicians can miss things. My belief is that any professional licensed facility would willingly address this problem. I really hope you will provide more detail/context.

The work was done by lithia Hyundai and was under warranty when it failed.