2nd gen Trans fluid change

Hey guys, I have a question about whether I should change my transmission fluid or not. The truck has 140k on it. 2013 Tacoma access cab 4wd Automatic 4.0. As far as I know, the fluid has never been changed. The dealership last had it at 87k when the last owner purchased it but no records of any service done to it. In some cases, I have heard it is better not to touch anything. It is lifted 6inches with 33s and the truck does also have a dyno tune with retuned trans shift points. Let me know what you guys think. Not sure if this has been talked about or not cause I could not find anything with similar info so sorry if this is a repost.

 

I have a 2012 4.0 with 118k on it and other than front brakes and rotors, battery, & tires about 86k, I decided since I am keeping it because it runs well and gets me where I go, at about 110k I had a local shop that I know the owner do the front & rear ends, transfer case and transmission fluid change. Normally I would not do it, but figured what the hell. The trans was just a drop the fluid and replace, and all the fluids looked pretty good and minimal filings on the plugs. There is a good write up here that tells you how to do it if you want, but as a retired mechanic, I am too old and don't fit under the chassis on a creeper anymore, so that's why I paid to have it done. The dealership was way out of line on cost for the work to be done. This is just my opinion, hope it helps.

 

I would do a full DIY flush, to include replacing filter, gasket and the cleaning of magnets. Plenty of step by step tutorials, it’s an easy job, you’ll save a lot of money doing it yourself and you’ll have the peace of mind that your transmission is set for the long haul.
Here’s one to get you started.
https://www.tacomaworld.com/threads/diy-full-flush-for-automatic-transmission.68462/

 

I wouldn’t do a flush but just do a change since it’s never been done before. That’s what I did when I bought my truck at 84k.

 

You definitely should replace the ATF filter. How the old ATF looks can help you decide on completing a drain/refill, a full flush, or none. If the ATF or the ATF pan magnets contain metallic particles, you don't want to complete a fluid change because removing that material can cause transmission slippage. If all you have in the pan is black sludge, you can feel safe doing a drain/refill or full flush. With that mileage, most will recommend a drain/refill every 30-40 K.

 

https://www.tacomaworld.com/threads/how-to-drain-refill-automatic-transmission.63851/

https://www.tacomaworld.com/threads/diy-full-flush-for-automatic-transmission.68462/

Start with one or two drain and fills if the fluid looks okay on the first drain I'd say go forward with the full flush. I did a full flush at 140k still going strong at 235k.
My fluid didn't look too bad when I flushed it.
https://youtube.com/shorts/AY97_4MBIwU?feature=share

 

Dropping the pan, cleaning magnets and replacing the filter takes all of an hour to do. It's really quite simple and there are many thorough how to's on the subject.

 

I was in the same boat as you with my truck. I tried to convince myself it didn't need it mainly because I was intimidated by the whole no dipstick issue. That, and somewhat fearful of having issues after doing it. I'm glad I did it, the process was easy, just a bit time consuming. The truck shifts smoother and I no longer need to question what condition my fluid is in. Moving forward, I plan on draining the fluid a couple more times to get as much new stuff in as I can without doing an entire flush. If you are going to go for it, if you don't already, get a scangauge or ultragauge and program it to read pan and converter temps. It'll save you from the shifter ritual to enter temp check mode.

This post is excellent and is what I used when I did mine.

https://www.tacomaworld.com/threads...on-pan-and-filter.726329/page-5#post-27738272

 

Drive it till it dies.

I'm at 227,000 on my factory fluid with no issues. Still runs like new. The guy who owns the local transmission shop is approaching 400,000 and has never changed his. He works on transmissions every day and says he sees no difference in longevity between those who just drive them and those who change it regularly. You can literally spend more changing the fluid every 30,000 miles than it will cost you to have the transmission replaced at 400,000 miles.

And FWIW, I've been driving since 1974 and have never changed the ATF in any vehicle I've ever owned. That is several million trouble free miles. There are almost 1/2 million combined miles currently sitting on my driveway. All with the factory transmission fluid in them. If one of them dies tomorrow I'm way ahead financially.

 

Drain and fill, drive for a couple of hundred miles then do another drain and fill. After you've driven the second "couple of hundred of miles" drop the pan, clean pan and magnets and replace the screen/flilter. Make sure the fill plug will loosen before draining the fluid. Also, hit the pan bolts with some PB Blaster or similar each time you drain and fill. That way when it's time to drop the pan the bolts are prepped and ready just like a prom queen on her big night.

At your mileage along with it being dyno tune with retuned trans shift points, I'd stay away from a flush.