Transmission repairs can be a costly expense. A little regular maintenance can go a long way in prolonging the life of your transmission and saving you big money on those repairs. A little sludge buildup is normal, but ignoring your recommended maintenance schedule can cause headaches down the road. Most manufacturers recommend transmission maintenance every 30k miles, but that can vary depending on your own driving habits and requirements. If you haven't had maintenance done in a while, or never, it might be a good idea to see where you stand.