Transmission Oil Change

[darrel]

want to change my atf. Now have dexron III and want to go to dexron vI. If I just drain and fill only about 3 quarts is drained. My question is, What would happen if I started the engine with the trans drain plug out? Would more oil come out? Would the trans be harmed in any way?

[Bob C]

I would not start the engine with the drain plug removed. It can't be good for the tranny. You could be running a lot of parts without any lubrication. I would use the cheaters method of tranny flush. The exact method is described here on the forum.

I know that it involves removing the hose between the radiator and tranny cooler, running the engine and replacing fluid at the same rate that it is pumped out.

[waiter]

Darrel,

I have heard of this method, it makes sense, but I have never done it, so can't testify to it.

Drain the tranny and refill with new stuff. (three quarts)

remove the tranny cooler return line that comes out of the bottom of the radiator, follow the lines, the return is the one that enters the pan.

Connect a hose to the fitting on the radiator, doesn't need to be perfect, there is no pressure here. Put the other end into a can or jar capable of holding at least one quart.

Start the truck and let it run until the can is full to 1 quart. shut the engine off, add one quart to the tranny,

Repeat this sequence until the fluid that comes out of the cooler is clean, new fluid. (should take about 3-4 additional quarts.)

If you do this, do a writeup, take some photos, and post it here.

John MNc

88 Dolphin 4 Auto (For Sale)

[Maineah]

The method John suggested works, your return line is the lowest one on the transmission it goes to the very rear of the transmission. A qt jug will fill fairly fast actually a couple of qts is fine it won't hurt any thing a helper would be a good ideal. You don't have to drain the pan first just replace what is pumped out as you go when the fluid comes out of the line bright red your done should take 7-9 qts. By the way do not block the return line (pinch the hose or any other method) if you do the pressure will instant climb to around 120 psi (the system is open loop) and you'll soon be covered with oil when the rubber line blows out this is where the helper comes in to turn off the engine when your bucket fills. Also an idle is fast enough.

[stamar]

A passive flush is great.

But if you can get the dexron six for cheap just drain and fill three times.

First time 50 percent new 50 percent old.

Drain fill again quickly now 75 perxent new 25 old

Third time 87 percent new. Thats good enough.

Fourth tine 93 percent . Also the three or four drains remove the dirt. The one 100 percent drain is going to be super dirty soon as its lots of detergent all at once on filthy parts.

Im not saying its not good but just multiple drain and fills is the best way.

Perfection is two passive flush

Or perhaps once youre on the ball passive flush every 50k miles. But for the new to you toyhome do drain and refills.

[stamar]

as i was looking through passive flush write ups i came across this one

http://hubpages.com/hub/Toyota-Camry-5SFE-ATF-Transmission-Fluid-Change

now this is a totally different transmission. however, the capacity is exactly the same as ours so every thing in the write up is the same as ours. the trans lines look the same.

overall its just like our transmissiion however our transmission doesnt want dexron 3 it wants dexron 2 or 6.

on the other front ive changed my fluid 4 times and it appears 100% clean. the 4th time was the end i dont see any difference between my fluid and new. 3 times there were still some dirt and particles but 4 times i pronounce it functionally clean.

Youve got to figure that even at mathamatically 93% clean that the dirt is starting to settle more at the bottom, more of the remaining dirt comes out in the last two drain and fills. its functionally 100% clean and I didnt do anything risky or involving extreme concentration or my trans will be ruined.

now on the other hand.... a passive flush would have saved me some money in fluid. cant knock it.

But it seems more like something to do when the atf youre using is super expensive like youre redline or mobil 1 atf and 6 more quarts is going to cost you 100$