How do i change my tranny fluid?

[JeremyL]

I have a 92 corolla with the 3 spd automatic and my hayne's book doesnt tell me anything on how to change trans fluid

[jjsagain]

i don't have first hand experience with your vehicle but did have a 90 geo prizm. You can do a flush and fill at your local zippy oil change place or you can drop the pan and change the filter in your driveway which is a messy situation at best. The other alternative is that you can suck out a good share of the old fluid either by a syphon using gravity or quicker mode using a vacuum syphon device. I have done it both ways on various cars and feel the vacuum syphon device at about 50 bucks thru JC whitney or another similar source pays for itself very quickly. If you use the syphon and take out most of the fluid on the first pass then do it again say at next oil change you get a pretty good change and it is not messy and very inexpensive since once you have the stuff to do it the only cost is the fluid itself which is really pretty cheap.

[kingpin]

i have an 01rolla 3speed auto and changing the trans oil wans't that hard. you'll need a pump to suck out and put in the differntial fluid and the trans pan you'll need a lot of rags it get messy. i'm not sure how your model is setup but try checking out the haynes book for93-02 it might help.it has more detailed info and pic to help. i love that book!!! good luck hope i helped some

[JeremyL]

it had a drain nut on the bottom of the pan so i just drained it and refilled it, was really pretty easy

is there a seperate differential? this is the first auto ive owned and im use to stick trannys

[Hook]

removing the drainplug only gets out about half of the total fluid in the tranny since most of it is stored in the torque converter and just dropping the pan is messy...u REALLY don't want to hafta wash that stuff off ur driveway

the best way is to disconnect one of the two cooling hoses that run from ur tranny to the radiator, the return line is best since u get to flush out the stuff that's coming out of the radiator as well

just disconnect it and stick one end of the hose (or u can just attach a drain hose) into a drainpan and start ur engine....now u hafta replace the fluid that comes out so it's best u use some el-cheapo tranny fluid and pour in at about the same rate that it's coming out...it takes about 7-8qts (as opposed to the 4qts that u'll get if u just pull the plug or drop the pan)

roll with that for about a week then repeat the procedure with the good fluid

[Hook]

oh, about Jeremy's question as to the differential...

if u look to the rear of the tranny closer to the firewall u'll see a large 19bolt...this is the drainplug to the diff...remove it and drain, remove ur speedo cable and make a mixture with 1/2 ATF and 1/2 motor oil...u're pouring your mixture into the opening where ur speedo cable is connected to the point where it just now starts to come out the drainhole...plug the hole with the bolt and reattach ur cable

[JeremyL]

where is the speedo cable located?

"the best way is to disconnect one of the two cooling hoses that run from ur tranny to the radiator, the return line is best since u get to flush out the stuff that's coming out of the radiator as well"

is that the line that connects to a copper looking fitting on the bottom middle of the radiator? so if i pull that off and run the engine that will flush out the remaining fluid? do i need to add fluid as the engine is running?

[JeremyL]

i was thinking of something else too. could i disconnest the lines that go into the bottom of the radiator (which im assuming is a factory tranny cooler) and just install a universal transmission cooler?

[Hook]

is that the line that connects to a copper looking fitting on the bottom middle of the radiator? so if i pull that off and run the engine that will flush out the remaining fluid? do i need to add fluid as the engine is running?

if it's one of the two tiny hoses at the bottom of the rad, then u're in the right place...and yes, u fill while u flush...it's a messy process so make sure u have the fluid running into a drainpan and our as u drain....use a cheap ATF first just to get all the old stuff out first...drive it about a week and then repeat with the good stuff

i was thinking of something else too. could i disconnest the lines that go into the bottom of the radiator (which im assuming is a factory tranny cooler) and just install a universal transmission cooler?

yup, that's fine...it's actually advised to run ur aftermarket tranny cooler in series with the stock tranny cooler in the radiator, but I've seen large universal units installed that do as u suggested and totally bypass the radiator...this allows the engine to run a bit cooler since it now becomes dedicated to watercooling no longer has both hot water and hot tranny fluid running through it...

mines is a small unit (space and the location of bumper vents limited the size) so it's in series with the stock tranny cooler as supplimental cooling

[JeremyL]

how would you run it in series? with a t fitting coming off each tranny line?

the way i drained it was i disconnected on of the line and stuck in the hole in my oil pan and just ran it in neutral while pouring fluid in went through about a gallon of fluid and then just levelled it off with the dipstick. is there any advantage to removing both lines while you run it?

[Hook]

how would you run it in series? with a t fitting coming off each tranny line?

nope, that's parallel u just described there....in series means connecting the aftermarket cooler between one of the lines and the inlet to the stock cooler in the radiator....my mech told me just this week that it's better I run the tranny cooler separate from the radiator since, like I said before, the rad becomes more efficient at cooling the engine and the universal ATF cooler becomes more efficient at cooling the tranny fluid

the way i drained it was i disconnected on of the line and stuck in the hole in my oil pan and just ran it in neutral while pouring fluid in went through about a gallon of fluid and then just levelled it off with the dipstick.

that's about the way...but a typical tranny holds about 7qts of ATF so u only did 1/2 the job

is there any advantage to removing both lines while you run it?

nope, none whatsoever...remember one line goes to the radiator and the other is the return line, so since it only flows one way, there's no advantage to pulling both lines to drain it