I am going to go ou ton a limb and say you sold business with vehicle all on owner financing, you holding paper? Otherwise why would a payment for something you own free and clear be even tied to a loan?
And by "outright" is or was this vehicle fully depreciated? Since you owned it outright there would be no bank loan you would have to reduce by making any payment to a bank. If it had become encumbered as collateral for a business loan you had in place prior to selling the business then you did not own it free and clear on date of sale.
If the loan is all you owing the bank should it not have been eliminated entirely when you sold the business? What did you do with those proceeds? Was there not enough to clear off the entire loan?