Question

I cosigned for my father in law last year on a truck. Since then he had defaulted on making the payments, and so as the cosigner I began making the payments for the whole year. It has been a financial burden ever since but I couldn't allow it to get repossed, and go negative on my credit. Since then I allowed him to have the truck in his possession. For the past year he had not had it registered,or insured due to his lack of employment. To top it off I recently witnessed him driving erratically and under the influence. It was then that I had him render the vehicle to me. It was a short time later that I was able to sell the vehicle. Do to us not talking and him against the fact that I reposessed the vehicle he refused to sign off the pink slip. So I signed his name. Am I in any legal trouble for doing so?