One of the most debated topics when it comes to automobile maintenance is transmission fluid. Everyone has their own opinion on when the transmission fluid needs to be replaced. In this article, we will try to demystify the quandary.
Transmission oil is one of the most crucial fluids running through your car. How often you need to change it varies by the make and model of every car, and is very debatable at best. Engine oil is primarily a lubricant. Transmission oil, on the other hand, serves as a lubricant, coolant, and hydraulic fluid that helps facilitate smoother gear changes.
High-stress driving conditions like stop-and-go traffic lead to faster transmission fluid deterioration. In such cases, it is best to keep track of your fluid levels. Best be aware of the condition of the fluid before you find yourself footing the bill for transmission repair, which is never cheap. But how often do you need to top up or replace the fluid? All manufacturers lay out the basic intervals in their service manuals. It is best to consult the manual and perform necessary top-ups and replacements as specified in it.
Some transmission fluids need to be replaced every 150,000km, while others can last for as long as 250,000km. If your driving involves a lot of high-stress conditions, it might lead to reduced fluid life, but not substantially. Many workshops urge car owners to replace the fluid at more frequent intervals than recommended by the manufacturer. Relax, step back, and reconsider with a cool head if you really need to do that. Manufacturers have spent countless hours testing and validating every single part of their models, which is why they know when consumables need replacement.
Worn transmission oils turn darker often because of dirt and debris they collect over the course of their operation. This does not always mean that they need to be replaced with fresh oils. Some workshops show you the debris to have you agree to replace the oil. Even replacing the oil is a specific process that should be followed meticulously. Do not force out the oil instead of letting it drain naturally. This is what happens with most transmission flushes. Manufacturers recommend against such practices (Honda for one, among others). Keep this in mind before you agree for a flush.
As a rule of thumb, do not touch transmission oil until and unless your vehicle is getting affected by shifting problems. Some mechanics also say that as soon as you replace old oil with fresh fluid, the transmission is susceptible to failure or breakdown. We find this opposite to logic and not worth thinking over, but fresh transmission does not magically cure slipping gears, rough shifts, or other mechanical problems. Sometimes the problem lies in defective parts inside the gearbox.
Finally, do not believe claims of certain transmissions being sealed for life. As long as a transmission is mated to an outside system, there are multiple entry points for outside pollutants to besmirch the internals of the gearbox. For cars that claim to have no need of transmission fluid replacement for life, check the status of the fluid once you clock more than 150,000km on the odo anyway.