Whether or not you should fix a transmission or scrap and replace a vehicle depends entirely on the type and age of the vehicle in question. If it's an older car, then sometimes the price to replace or fix the transmission can cost more than the car is worth. At this point, it is better just to sell the vehicle for spare parts. If you have a newer car that is worth 10s of thousands of dollars, then paying to fix the transmission may be worth it, especially if the vehicle has quite a few years of life left. Outstanding liens on the vehicle may also come into play. You may not have the option to sell the car in the event you owe more than it's worth and cannot offset the negative equity.