Insufficient transmission fluid, shifting into drive or reverse while the engine is in a fast idle, driving with a cold engine, downshifting at traffic lights and using unnecessary transmission additives are practices that cause transmission damage. Monthly maintenance to prevent problems is the optimal way to keep a transmission in shape.
Insufficient lubrication of transmission components causes serious heating and wear damage. A yearly change of transmission fluid is recommended by most auto manufacturers. A transmission fluid reservoir that requires frequent refilling may indicate a leak, demanding immediate attention.
Abrupt shifting into drive or reverse while the engine is idle causes the transmission’s components to engage forcefully, leading to premature component failure. Downshifting to slow a vehicle instead of using the brakes forces components to shift from high RPM to low RPM, causing excessive wear and damage to clutches and bands.
Transmission additives usually do more harm than good in the long run, with additives, such as Lucas, expanding rubber seals to the point of failure with prolonged usage. When transmission rubber seals fail, they leak fluid, causing extensive damage to components.
Vehicles with manual transmissions should always be promptly shifted to the optimal gear, accounting for speed, inclination and terrain type. Driving for prolonged periods of time at too low or too high a gear causes premature transmission failure.