About Me

Angela's Articulate Collection of Car Service Secrets, Tips and Tricks

Hi, my name is Angela, and as the wife of a mechanic, I was constantly tripping over car parts and complaining about the rows of project cars lining our garden. However, after a few years, I quit complaining and actually found joy in the art of auto repair. Inspired by that classic book, "Zen and the Art of Motorcycle Maintenance", I decided to start working on cars with my husband. This blog is the culmination of everything I have learned and more. I hope you enjoy reading it and that my tips and ideas guide you toward a healthier car and a happier, safer driving experience.


Angela's Articulate Collection of Car Service Secrets, Tips and Tricks

Should You Always Flush Old Oil From Your Transmission System?

by Keith Simpson

Anyone who has ever owned a car knows that it's important to service the vehicle from time to time. Conventional wisdom dictates that you should change the oil and filter on your engine and gearbox in accordance with the manufacturer-recommended intervals and always replace them with high-quality parts. Some mechanics also recommend that you flush out the transmission system to make sure that all the old oil is chased from the nooks and crannies into the pan beneath. But, is this always the best approach?

Finding The Hidden Oil

Due to the transmission's design, old oil cannot always fall down into a collection pan through the force of gravity. Some of it may be stuck in the narrow channels or cooler lines and may sit stubbornly in place when you're trying to effect a change.

Flushing The System

Thankfully, qualified mechanics will have a special machine that is designed to flush out the system and force this stubborn oil out through the drainage hole. This would allow you to replace it with brand-new lubricant, which theoretically would be a vast improvement.

Do You Need To Be Cautious?

You may need to think twice if the vehicle is particularly old or if you have not changed the transmission oil for an extended period of time. After all, the lubricant may start to thicken as it gets older, and this may alter its properties. The thicker oil might help some aging mechanical parts work more effectively, especially the clutch mechanisms. There is a risk that the transmission may start to slip or shift out of gear if you were to replace the older oil with fresh and, therefore, thinner fluid instead.

There's also a risk that you could damage the rubber seals as the old fluid is flushed through the system. Some of the contamination in those harder-to-reach places may get stuck in the narrow oil channels as it is being flushed out.

What To Do Next

Still, it is far better to consider servicing your transmission than leaving it to sit without any attention. After all, during a routine inspection, mechanics may find early warning signs of a problem. So, if you're unsure about the age of your transmission system and don't know whether you should flush everything through, talk with a car servicing company first. They will be able to advise you and will always do what is best for your particular vehicle.