30,000 or 60,000

[SteveSRT8]

all you get is whatever the pan holds, usually 3-5 quarts on many cars and trucks I've done.

As we all know most automatic transmissions hold a great deal of fluid.

 

[berniedd]

My take on this is you're better off dropping the pan and changing the filter at 30,000 mile intervals. ATF (and engine oil) go bad because of additive degradation AND particle contamination. Granted, the filter will remove major particulates, BUT NOT all of it. You will be removing some of these smaller particulates and replenish the additive package earlier if your service interval is 30,000. If you wait till 60,000 miles, the additives are nearer the stage where they're spent AND particle volume will be much more. Wear is therefore expected to have occurred more in this situation.

 

[Boss302fan]

I like to do ATF at 30K.... Better safe then sorry.

 

[Mark_S]

Thanks for the replies.

Awhile back, I asked undummy what the manufacturer meant when they said to change the fluid every 30,000 miles. Did they mean to drain and refill or did they mean a complete flush? He replied, drain and refill.

That being the case, I was curious as to opinions/expertise. Since a drain and refill gets only about 1/2 the fluid, would a complete flush allow you longer intervals between changes?

 

[Boss302fan]

I would do the drain, filter change and refill...