My son and his wife signed a loan agreement to purchase a trailer she has never used her married name for any business transactions only her maiden name she feels her credit will remain sacred if she doesn't use her married name any way she left my son and wants him to sell she doesn't want her credit ruined if he would default he wishes to keep the trailer. Oh they have only had it 3 months .

If he can afford to keep up the payments without her then I don't see why he would have to sell it.
She is thinking sell it to keep her credit good but she needs to consider the depriiciation of vehicles and homes once they are sold.
I doubt he would be able to get a decent amount for it if he sold it. The only way I see that that might work is if he sold it and gave the cash in hand to pay off the loan so that he doesn't have the interest rates to balance the difference on the depreciation. Not sure enough how all that works to say though.

This is more of a divorce issue, the ownership of the home should be addressed in the divorce settlement, If she wants to sell her part to him, and he can refi on the home, great, if he wants the home he should do it. If he does not want it, they should sell it together and split the money

Yeah refinancing is what he would have to do.
Three months I can't imagine that they have much money put into it at this point.