How to Drain/Refill Automatic Transmission

Lets see ..... I use 1 paper clip every 100,000 miles for transmission service.

I think I will only need about 3 maybe 4 for the life time of the truck.

 

Guilty.

I practice the KISS principle in life.

 

Does TEMP CHECK MODE use the same temperature measurement method that PIDs in a Bluetooth OBD dongle (or ScanGauge/UltraGauge) use?

 

Frankly, I don't know. Also, don't care.

I do know it is the system that Toyota installed on the truck.
So, it is accurate enough and I can't introduce an error of some sort in the Temperature Check

 

Exactly my point. We know that TEMP CHECK MODE was meant to help with setting the tranny fluid level.

Using temp guns on the pan, OBD dongles, etc.. might work but might also be entirely wrong. Transmission rebuilds are expensive. Use the freaking temp check mode and do it right.

 

Accuracy is only based on need.

Examples.
A Smart Bomb with a 300 m blast zone that can hit the target within 1 m is insanely accurate. Does it need to be that precise, probably not.

On the other hand, Laser surgery on your eye an error or 2 mm could result in loss of site. This system must be accurate to the micrometer level.


Temperature Check Mode accuracy in the transmission probably doesn't need to be within 1 degree, but the accuracy should be within Toyota's supplied onboard system

 

This thread is a bajillion posts long, so I haven't been able to see if someone else has brought it up and answered already, etc. but here goes... My taco has around 270K on it now. I bought it around 100K ago, so it had about 170K when I got it. I'm contemplating changing the tranny fluid. I spoke with the previous owner and he said he changed it at 100K. I assume that was the only fluid change. Is it safe to change the fluid with this history on it? I've heard stories of trannys starting to slip if not changed during its life and then finally changed. Any opinions on my situation?

 

If it works fine, and you want to squeeze another 50k out of it then don't touch a thing.

But if you are thinking about selling or scrapping it, the mildest thing you could do is a simple drain and fill, which will only replace 1/3 or 1/4 of the entire fluid capacity.

 

understood, there were just so many threads going back and forth for the pan temp on ultragauge, and different input codes for the ultragauge, that ive never been 100% confident that its reading what the actual check temp is.

 

Agree, thats how i did it the first time. Its just easier if i can get a direct reading and know where the temp is, rather than waiting for a light. Especially if changing in very cold weather, which i will be doing, just to have an idea if its close or not.

 

I want to keep it and keep the transmission alive as long as possible without a rebuild. So does that still mean doing nothing is still the best option? Would the simple drain and fill most likely increase chances of it slipping in the next few years?

 

I would suggest to do an enhanced Drain & Fill. Include a pan drop with a filter change. Its just a little bit more effort and the cost of the filter is less than $20. Some will chime in to say the filter can be "cleaned" and reused. IMHO, a used filter can not be thoroughly cleaned and the replacement cost is low. Doesn't make sense to risk a $4K+ tranny on cleaning/reusing a filter to save $20.

This will give you the opportunity to clean the pan and the magnets and install a fresh, clean filter. Still going to need the same amount of fluid as a Drain & Fill.

 

2014 DCSB, 59,000 miles, a pavement princess.

Because my 2006 Tacoma had the "slightly less than full" transmission from the factory, I checked this on my 2014 when new. It was full.

Today I did the procedure as listed by the OP... Everything went as planned. New crush washers and replaced the 5mm overflow bolt with an OEM drain bolt. 2.9 quarts came out, put in 3.3 quarts, brought to temp, and about 0.3 quarts came out... maybe less.

Did town and freeway driving, still smooth as silk. Good work OP.

 

For those interested in replacing the 5mm allen overflow bolt with a drain bolt....

 

Is everyone replacing this because the hex key strips?

 

Some people have. But it's mostly just for convenience.....one 14mm socket required for both

 

Man I'd almost go the opposite way and use the same hex key bolt for both. A 14mm socket on a tiny bolt on a thin aluminum pan is too much in the wrong hands.

 

Do you have "wrong" hands??

 

Nope, but some people have the dexterity of a gorilla.. literal steak fingers that overpower everything they touch. And then when they strip a fastener, those people claim the engineers did a bad job or write 1 star reviews on products.