Q: Advice on changing the fluid in the differential

Differential fluid on a lot of modern cars has it built in the transmission. For example, for a 2002 Toyota Camry, when you change the transmission fluid you are also changing the differential fluid. They share the common fluid. But on other vehicles, where the differential is separate, normally, it’s a good idea to change it every 50,000-60,000 miles.

Because, it does get dirty. It’s not like the automatic transmission where it’s going to change the shifting, but if it does really dirty, then the seals can get bad. They can get dirt on, wear out, and start to leak. And it can also wear the gears a little bit. It’s nowhere near as crucial as changing automatic transmission fluid. But you’d still want to change them every so often. If you want to have your differential gear fluid inspected, they will let you know if you need to know if you need differential oil replacement.