Automatic Transmission Tips & Advice
How often should I change my automatic transmission fluid?
The short answer is to check your transmission fluid regularly. It’s easy enough to do and may save you lots of time and money.
As to changing it… opinions vary greatly. Some vehicle manufacturers claim you never have to do it, others suggest a very long time between changes – upwards of 60,000km. Based on some of the transmission damage we see at A Automotive Services, we suggest you change your auto transmission fluid about every 25,000km.
As much as nine out of ten faulty transmissions are the direct result of overheating.
The fluids being used are getting better, but they have to handle incredible rigours inside an automatic transmission, where friction generates tremendous heat. Most of these fluids are designed to operate well at about 80°C. This temperature is normal for cars moving at even speed with no undue stress. However, under fast acceleration or when towing, the temperature in your transmission can rise sharply, causing transmission fluid to work less efficiently and reach the end of its useful life quicker.
What happens at high temperatures is that the auto trans fluid oxydises – sometimes even giving off a burnt smell. As it gets hotter, the fluid becomes a less effective lubricant, causing wear in the transmission. The fluid itself could leave a varnish-like film on metal surfaces, further hampering performance. At even higher temperatures, rubber seals harden, which can lead to leaks. If this happens, you’re looking at an expensive repair job.