If you wish to speak by phone I am still willing to do that. In the meantime, the answer to your question is as follows.
Because the state of Texas is a Community Property
state, that means that all debts incurred by either spouse during marriage are the joint obligation of each spouse. So regardless of whether your daughter signed the truck loan paperwork, under TX law the lender may look to either your daughter or her ex to collect the money on the loan and in the event of a default, the lender may sue either party.
Now, the Marital Settlement
Agreement may read that her ex is responsible for the loan on the truck. However, under the law that is only binding as between your daughter and her ex. The divorce decree does not have the legal effect of preventing the creditor from seeking to collect on the loan from your daughter.
Your daughter may file a Motion for Contempt and Enforcement in the family law
court and ask the court for an order that her ex make good on the loan, and the judge will make that order. However, she cannot avoid liability on the loan to the creditor based on the court order making her ex responsible. Divorce court orders cannot legally take away contractual rights that third parties may have against the couple---because the third parties are not made parties to the divorce action, and cannot be under the present state of Texas law.
You may reply back to me using the Reply link and I will be happy to continue to assist you until I am able to address your concerns, to your satisfaction.
Kindly, remember to rate my service to you. That is how I am credited for assisting you.
I wish you and yours the best in 2015,