Legal Question in Civil Litigation in Pennsylvania

Even with improved credit it is unlikely that the financing company would agree to "take you off" the loan even if you could get your ex to do his part. It is more likely that re-financing would be required. This would cost additonal money and makes it unlikely you ex would move forward.

Unless you had a separate legal agreement regarding him taking you off, or agreeing that only one of you could force the sale of the truck, I can think of no other legal action you could take to compel him. If we were talking about joint ownership of real estate, you could force the sale by filing a partition action. I do not believe that remedy would apply to anything other than real estate.

(I just did a quick Google search to confirm that opinion and did not come up with anything to indicate that you can partition a truck.Stronger confirmation would require direct legal research.)

As the co-owner, you do have the right to assume possession of the truck, but that type of tactic would likely go "nuclear" and is not recommended.

My suggestion is that you hope for the best and resolve not to help boyfriends in such ways in the future.