Change Transmission Filter or Just Drain & Fill?

Got a 2nd Gen 2009 4x4 V6 Tacoma with 170k miles, Bought it used and I've gone 40k with zero problems. It appears the Transmission has never been serviced. The transmission works very well as is.

Should I take the gamble and drop the Transmission pan and change the filter?
Or, should I just drain and fill? (keeping about half the old fluid and filter)

How long can an original filter last?

 

It is not a gamble to replace the ATF filter and do a drain/refill. The gamble is doing a flush. I would get peace of mind dropping the pan to see how it looks in there.

The filter in our V6 rigs is a metal mesh. Many clean it out with acetone. I replaced mine at 130K. It was only about $30 for a Wix filter.

 

filters are generally not lifetime components.

drain and fill does not address cleaning potential magnets, getting more fluid out, and renewing the gasket.

 

Thanks for the info. These answers are a big help.

 

I dropped the pan, cleaned the magnets & installed a new strainer at 160K! (tranny was never serviced prior and no issues) The magnets had minimal film. I am at 194K and still performing great!!

 

Great info! I hope for the same results!
But I'm not sure exactly what you did other than replace the filter.
Did you drain and fill at each of the intervals in your picture? Or are you saying the new filter cleaned your old fluid?
I'm assuming you drained fluid, dropped the pan, discarded the old fluid, Cleaned the magnets, replaced the filter and refilled with new fluid.

 

Why is dropping the pan a gamble?

 

The day before I dropped the pan to clean it, the magnets and swap out the screen/filter, I sprayed a little PB Blaster on each pan bolt just to make sure they'd all back out without any issue.

 

I didn't phrase it accurately enough.
I was trying to say, "Should I dump all the fluid from the pan?" This is because I've heard so many disaster stories about slippage after replacing all the fluid.
A lot of people say "Just drain and fill." But Chuy above clarified that a flush would be the real gamble.

 

You’re dumping the majority of the fluid in the pan when you do a drain and fill. There’s probably only about a quart left in the pan after you drain it. With the pan down you’ll probably drain about 4 quarts total and I believe the system holds 12.

 

same!

 

I drained the pan and caught all the transmission fluid as I was removing the pan. (about 4.6.quarts) So after installing the strainer & pan (new gasket), I added 5 quarts of fluid and did the level check. About 1/3 of a quart came out during this process. I performed 2 more drain & fills that were 3 quarts each. Gather the bucket and plastic tub at Lowes.