on loan but not deed..ex sold house without me signing off on the loan

If you were on the mortgage and title, you would have had to sign off on the sale of the home. I would check with the title company that closed the sale to obtain a copy of the hud-1 settlement statement. That will show the buyer/s sellers and all signatures.

General rule of thumb with a married couple - it takes one to buy and two to sell. You should definitely look into this to see what happened.

If you were not on the title (deed) to the property I don't see any restriction to him selling as you were not technically an "owner" and the existing mortgage holder would simply be accepting the pay off of the mortgage. If you were not on the title/deed there likely was not any paperwork you'd need to sign at the closing. If you have concerns check with a local real estate attorney or title company. If you were owed anything under the terms of your divorce that is a separate issue.