When searching for a used transmissions for your vehicle, make sure to determine the make, model, year, and engine make so that you can match. Examine the transmission code, often on a sticker or printed on the original transmission or owner’s manual. Ask for the mileage and record of the second hand transmission, if a refurbished or repaired one. Ask for warranties or guarantees from the vendor. Verify that it isn’t damaged, or worn, or corroded, and ask if you’ve used it. Collect if possible the VIN of the donated car so you can know what its history is. So watch for promotions and purchase from a trusted seller for best quality.