The fluid in your car’s transmission should be replaced every 30,000 miles. Over time, the assembly’s friction creates an enormous amount of internal heat. That causes the fluid to oxidize and lose its ability to lubricate the moving parts. Eventually, the lack of lubrication will cause the operational temperature to rise further, leading to varnish, cracked seals, and a loss in pressure. If your transmission fails, you can expect a hefty repair bill.

Below, I’ll quickly take you through the steps involved with changing your car’s transmission fluid and filter (it’s recommended that you do both at the same time). You can pay a mechanic to do the job, but you’ll save time and money by doing it yourself.

Draining The Fluid

If your car has an automatic transmission, it will also have a service pan that contains both the fluid and the filter. On the pan’s underside, there will normally a plug. Remove it and drain the fluid into a catch container. If the pan does not have a plug, you can drain the fluid when you remove the entire pan. » Read more: A Quick Guide to Servicing Your Vehicle’s Transmission