DIY Transmission Flush or Drain and Fill

[SZR48207]

I'd recommend a simple drain and fill once every 2 years. The point being, you want to replenish the additive package more than you want perfectly clean fluid. The additive package is what protects the transmission and it deteriorates over time, putting components at risk of greater wear.

The cleanliness of the fluid, within reasonable limits, is less of an issue because there will be media and magnetic filters in place to capture big particles. At the end of the day you have friction material floating around in the fluid anyway so wasting good fluid to achieve this is not a good use of resources.

What you might do instead is install an aux cooler to keep the temps down. City driving is [censored] on a transmission and heat can render a fluid useless under certain conditions.

 

[doublebase]

I am a fan of simple drain and fills, been doing them for years and believe they've extended the life of my transmissions immensely. I have a Honda Accord with 289,000 miles...original transmission...drain and fills every year. And that's a car that's known for transmission failure, big time - I believe the simple drain and fills saved it from failure. I do this with all my cars and I haven't lost a transmission yet (knock on wood).

 

[4WD]

+1 ... so much so I added a drain plug and spin on filter - 20 minutes and no mess ...

 

[DoubleWasp]

Originally Posted By: Reddy45


The cleanliness of the fluid, within reasonable limits, is less of an issue because there will be media and magnetic filters in place to capture big particles. At the end of the day you have friction material floating around in the fluid anyway so wasting good fluid to achieve this is not a good use of resources.


You clearly have little or no experience working with hydraulic systems.

In a modern automatic especially, that fine contaminant is a killer.