What type of transmission fluid?

Recently purchased my 2002 Tacoma 2.7l and I have been changing out the fluids. I have done everything but the transmission. I have no idea the last time the transmission fluid has been changed and what type was used. I plan on draining about 2 quarts from the pan than adding 2quarts and doing this over a period of a couple weeks till I go through about 6quarts to hopefully get mostly clean fluid. My concern is mixing different types of trans fluids. will it hurt my transmission? what type to use? dexron iii? please help

 

T-iv

 

I put this Castrol in both my 95.5 autos and have had no issues.

$27 Castrol TRANSMAX DEX/MERC ATF, 1 Gallon, Automatic , Black

https://www.amazon.com/Castrol-0352...ZPXH6GZQW5J&psc=1&refRID=8AWR0QWCWZPXH6GZQW5J

 

I use this stuff in all 3 of my Toyotas it's cheap and you need 3 gallons https://www.walmart.com/ip/valvolin...utomatic-transmission-fluid-1-gallon/15125768

You should flush it to get all of the old fluid out. Measure how much you drain out and if it's like 5 quarts put 5 quarts back in. Then remove the return line from the transmission cooler and stick it in one of the old jugs ad run the truck in neutral until it drains 2 quarts out. Then put 2 more quarts back in the transmission and repeat until you all 3 gallons are gone. In my experience you need 3 gallons to flush all of the old fluid out of the converter and the fluid runs blood red. A magnefine filter spliced into the tranny cooler in the line is a good idea especially if you dont drop the tranny pan and clean the magnets.

 

Curious if you tried searching this topic. It's been discussed a lot. I'm sure you'll find all the answers (and then some) to what you're asking.

 

I used Castrol Transmax Import and Toyota T-IV in the A340 automatic in my 2001 4runner. The trans seemed slightly happier with the T-IV fluid vs the Castrol transmax. the trans temp actually went up 5-8% on average after flushing completely and filling with the Castrol.
I plan on flushing my new 1st gen with Toyota T-IV.
An old transmission is 1 place that I do not switch to synthetic fluids.

 

this is inline on what a member here says using the CASTROL ATF in place of the OEM T-IV ATF the shifting not as good as using the OEM Toyota T-IV, he even tried using the Valvoline Maxlife in his truck but says it was better when he had the OEM ATF in the tranny was better than both the others

 

automatic transmission calls for DEXRON II but it has since been replaced with DEXRON III

DEXRON VI and above are a different formula and should not be put in a DEXRON III and lower transmission

Also, normally, DEXRON 4 and up are yellow while III and lower are red. So if you have red fluid coming you when you do your fluid change, you had D-III in there

 

I just did tranny fluid last month. Used t-iv and tranny seemed to shift a little better. Not sure what was in there before but it was black and I was starting to have issues on cold mornings with it shifting up. Mine is supercharged with 116k miles

 

What ever fluid you use is better than running old fluid that needs to be changed.

Be sure to stop by your local dealer and pickup some Toyota transmission drain plug "crush washers" for your 1st gen.

I try to keep 2 or 3 extra in my toolbox.