“I have a 2005 3.0 L Ford Ranger and I lost my owners manual. I would like to "ask a mechanic" how important is it to flush the transmission and at what mileage?” - Hank P.
Ford recommends changing the automatic transmission fluid in your truck every 30,000 miles, and it also recommends using Motorcraft Mercon V ATF (automatic transmission fluid). If you’re replacing the fluid yourself, Ford says that the transmission holds 10 quarts on two-wheel drive models and just under 10.5 quarts for four-wheel drive models.
Most automakers recommend automatic transmission fluid to be changed around 30,000 miles, but this will definitely vary by make and model. Of course, if the vehicle is used for towing or other driving scenarios that put excessive wear on the transmission, than the fluid will likely have to be changed more frequently.
The easiest way to tell the condition of your transmission fluid is to look at the fluid. Brand new, this fluid is red, but it doesn’t have to change color to be bad. Smell the fluid too, and if there is a burnt oil smell, it probably needs to be replaced. It goes without saying that dark, discolored transmission fluid is probably overdue for a change.
Those with manual transmissions aren’t exactly off the hook when it comes to changing fluids. While the thicker gear oil used in most manual gearboxes doesn’t have to be changed as often, it still must be changed at some point.