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DIY Auto Transmission flush?

479K views 523 replies 133 participants last post by  FJCamper1 
#1 ·
I'm coming up on 70k, so I have the usual service to handle and in addition I want to flush out the tranny..
I have the fluid (16quarts) and am not afraid to tackle this chore.

My intent is to:
Disconnect a line up front (at my tranny cooler) since it's easy to get to.
Open the filler plug on the side of the tranny and stick in a filler tube and funnel.
Put a drain bottle under the open line.
Start it up to pump out a couple of quarts at a time.
Shut it down
Add new fluid in the amount pumped out.
Repeat until I use up all the fluid that I have.

Check the level and top off as required.

Has anyone done this already?
Is my procedure going to work?
What am I missing? I've read that I should reset the ECU so it will re-learn the shift patterns. What else..

Thanks for any feedback (please don't tell me to take it to the dealer).
 
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#2 ·
I'm ready to do the same, I can't believe the dealerships say it's a sealed unit to last the life of the truck. I want to flush out the system also and seems the best way as I can figure is the way you describe above.

Come on all you experts! Let's hear it from you :bigthumb:
 
#3 ·
I've done it already. You've got it exactly right, except that there's no need to reset the ECU. Keep flushing until all the ATF coming out of the cooler line is fresh clean sweet and new. The easiest way is to put all four corners of the truck up on jack stands and put an empty 5 gallon bucket under the cooler line so you don't have to empty it during the procedure.
 
#5 ·
Hi 1911 :wave: Do you think 5gl of fluid is enough to flush the system out with starting the engine draining a few quarts then adding a few quarts and keep doing this procedure? When you do this does the Old fluid keep mixing with the new fluid added? Meaning that half is new and half new is emptied into the Bucket?
 
#4 ·
Sounds like a great way to flush out the entire system. I would probably want to drop the pan to replace the transmission filter as well.

What are your thoughts on installing a remote oil filter on the return side? A good flowing unit like a K&N oil filter should work right?

Thoughts?
 
#9 ·
I would probably want to drop the pan to replace the transmission filter as well.
There is no replaceable filter, only a metal "strainer" for the valve body. Waste of time to drop the pan IMO.


What are your thoughts on installing a remote oil filter on the return side? A good flowing unit like a K&N oil filter should work right?

Thoughts?
You'd have to be real careful about doing that; modern auto trannies are sensitive to the correct hydraulic pressure and I would be hesitant to introduce any back pressure into the system.


Hi 1911 :wave: Do you think 5gl of fluid is enough to flush the system out with starting the engine draining a few quarts then adding a few quarts and keep doing this procedure? When you do this does the Old fluid keep mixing with the new fluid added? Meaning that half is new and half new is emptied into the Bucket?
You won't need anything like 5 gallons of new fluid, IIRC a couple of gallons was all I needed. According to the FSM, refilling the system including a new (dry) torque converter is only 6 quarts, so 8 quarts should give you a little extra to flush everything. The empty 5-gallon bucket for a drain pan is just for convenience and less mess; the fluid comes out under pretty good pressure and if you use a regular oil drain pan you will likely splash ATF all over your floor. You still need to run the engine for about 60 seconds at a time, shut it off, and add more ATF and repeat. The auto tranny oil pump is very efficient and it will pump ATF out pretty fast. You don't want to run it dry, just low then refill every iteration. This procedure does a pretty good job of pushing the old fluid out with the new, and not mixing very much if at all. It is pretty obvious when all the old ATF is out because the fluid coming out of the cooler return line will turn bright red (new fluid) pretty much all at once. I always run it for at least another cycle after that just to make sure.

Does this answer your question?


2. Remove the transmission pan.
3. R/R the transmission filter.
4. Install transmission pan.
Not to belabor the point, but again, there is no transmission filter.


Have fun removing the pan on that transmission. It may give you a hard time!
That's if you can find it!:)
The pan is pretty easily accessible, but again there is reason to remove it unless you need to service the valve body underneath it.
 
#11 ·
This is exactly what I am planning but without the TCM/ECM reset. No need to IMO. I have not done this yet on the FJ but I have done this exact procedure on other AW transmissions and it works great.

I am not planning on dropping the pan. I'll drain ~2 qts at a time because you can't fill it as fast as it pumps out and you don't want to run it dry.

If the ATF coming out is dark brown, then it will take about 12-16 qts to get the new fluid coming out to be cherry red. Make sure you use a CLEAR output hose so you can monitor the color of the ATF coming out.

You can jumper the OBD port to get the ATF dash light to come on when it is time to verify the fluid level but you should be pretty darn close if you put in exactly what you take out.

DEWFPO
 
#13 ·
Thanks for the feedback guys.
Experience is always the best teacher, if only I could learn to listen more often.

The clear tube is a great tip!
I figured that I would run the old fluid out into a an old 5Qt motor oil jug so I would know pretty acurately how much was pumped out each time. Then I could drain that for the next cycle.
 
#14 ·
You won't need anything like 5 gallons of new fluid, IIRC a couple of gallons was all I needed. According to the FSM, refilling the system including a new (dry) torque converter is only 6 quarts, so 8 quarts should give you a little extra to flush everything. The empty 5-gallon bucket for a drain pan is just for convenience and less mess; the fluid comes out under pretty good pressure and if you use a regular oil drain pan you will likely splash ATF all over your floor. You still need to run the engine for about 60 seconds at a time, shut it off, and add more ATF and repeat. The auto tranny oil pump is very efficient and it will pump ATF out pretty fast. You don't want to run it dry, just low then refill every iteration. This procedure does a pretty good job of pushing the old fluid out with the new, and not mixing very much if at all. It is pretty obvious when all the old ATF is out because the fluid coming out of the cooler return line will turn bright red (new fluid) pretty much all at once. I always run it for at least another cycle after that just to make sure.

Does this answer your question?

Thank You so much! :cheers: I wonder how discolored the fluid will be with almost 75K onboard.
 
#15 ·
The total atf capacity of the A750F is between 11 & 12 qts.

DEWFPO
 
#17 ·
Anyone have a picture of the trans line going to the cooler? I`m planning on doing this myself and just want to get the general idea where this line is. Don`t want to chance undoing the wrong one. Thanks Steve
 
#19 ·
1911 posted these instructions a while back in another thread and I have just reposted and added my 2 cents :

You can short the terminals on the OBD plug between CG (4) and TC (13). CG is pin #04 (top row, 4th from the left). TC is pin #13 (bottom row, 5th from the left), and the "A/T OIL TEMP" light in your dash will turn on when it reaches 115 F and will blink if it exceeds 130 F.



After reaching the correct ATF temp, run through all the gears a few times, remove the level-check plug from the bottom of the tranny oil pan, and add the correct ATF through the side fill port with a hand pump until it just barely trickles out of the level-check plug hole. Put the level-check and fill plugs back in and you are done.

Or, you could measure every single drop you took out and every single drop you put in and make sure it balances out.

DEWFPO
 
#20 ·
Hi all

Just an Ideal?

- Have two buckets, one filled with clean trans oil and one empty.
- Hook a line from the trans cooler to the bucket with clean trans oil.
- Hook a line that went from trans to the trans cooler into the empty bucket.
- Run the FJ till all the clean oil has been sucked up.

Conclusion:
No issue with pump going dry and trans oil system should be flushed out as much as possible.

What do you guys think of this?

George
 
#22 · (Edited)
Finally getting back to this...
I did this procedure over the weekend, so for anyone looking to do it also, here is what you will need:

16 qts of WSATF from your dealer.
an empty 5qt oil jug that has the little see thru part and qt marks on the side (most of the oil jugs have them)
about 4 feet of 1/2"ID x5/8"OD clear plastic tubing
a funnel that fits inside the tubing above
( i picked up the tubing and a 1/2 pint funnel at HD for about $10 total)
a short length of clear tubing (3/8" I think) to drain the old fluid.
a 24mm box end wrench to get the fill plug off.

Procedure:
Start by opening the fill plug with the wrench, its on the passenger side toward the rear of the gearbox. Clean it up and set it aside.
From the engine compartment run the 1/2" tubing from the middle of the firewall back down to the fill port keeping it away from the exhaust pipe and cats. The 5/8" OD fits the fill port pretty nice and should not fall out once you push about 3/4" of it in there. I only pushed that much in and it did not leak while filling. Attach your funnel to the other end of the tube and tape it up with some electrical tape just in case.
Locate and remove the black tube on the bottom line of the radiator, this is the return line to the gearbox. Put your clear tube on the radiator nipple now showing. If it is snug you don't need a clamp since there is very little pressure. Put the other end into your empty 5 qt jug.
Now start your engine and watch as the old fluid goes into the jug. It should take about 10-15 seconds to dump 2 qts. Stop the engine and put that much new fluid back in by pouring it into the funnel. Repeat this until you have gone thru all 16 qts. Make sure that each time you dump some, you put exactly that much back in. By the time you have gone thru all the new fluid, the old fluid coming out should look new too...
Now clean up, put the plug back in, the return line on the radiator and give it a test drive.
This is from memory so if I forgot something, please post up...
Hope it helps..
 
#25 ·
Finally getting back to this...
I did this procedure over the weekend, so for anyone looking to do it also, here is what you will need:

....

This is from memory so if I forgot something, please post up...
Hope it helps..
bartt,

Awesome post. I'm sure this will save at least a few people some money, and give them needed confidence for tackling what the dealer makes out to be an overly complicated procedure. Thank you.
 
#24 ·
That would really help and leave any uncertainty :clap:
 
#26 ·
I understand everything you said the only thing I could use a picture of is the hose i`m supposed to remove from the radiator. I don`t want to remove the wrong hose. How much does 16 qts of AT fluid cost from the dealer anyway?
 
#27 ·
Open the hood and look down the back of the radiator. On the drivers side there are 2 small black hoses coming off the side of the radiator. There is one near the top and one near the bottom. The bottom one (the return line) is the one you want.
I think the fluid ran about $7 per quart from the dealer. I understand that there are some other mfgr's now (like amsoil), but I just it got from the dealer..
 
#28 ·
I've done this flush on other vehicles and used the upper (input to the radiator) hose as well. You just connect your larger hose to the upper hose as opposed to the lower radiator connection.

DEWFPO
 
#29 ·
Bartt,

Thanks for explaining which hose is which. I will be going with the dealer trans fluid also. Just to be on the safe side. I have about 8000 miles to go before I do this maint. Thanks again Steve
 
#30 ·
16 quarts to flush and refill the tranny? Isn't the Toyota ATF fluid about $7.00 a quart? If thats the case it just might be worth paying the dealer the extra $100 to flush it with the machine.

-B
 
#31 ·
Dealer wants like $300 to do the change... Save $200 that is really easy procedure.
 
#32 · (Edited)
deleted
 
#34 ·
Being the twisted soul I am, I want to replace the oil with one that gives higher pressures. Back in the day, the trick was to use Ford tranny oil in our hot rods with GM trannies for a bit more ooomph. Supposedly raised hydraulic pressures, resulted in slightly firmer shifts and less wear'n tear on the clutch plates. And though it may have been nothing more than a placebo effect, the few times I did this oil swap seemed to result in slightly firmer shifts.
Spposedly, B&M auto tranny oil was/is nothing more than glorifed, blue-coloured Ford oil.
Can anyone confirm or deny the theory? If not, can anyone tell me if it's possible that higher pressures would indeed have a negative effect on the transmission?
 
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#36 ·
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#35 ·
That would not be a good idea. Using a non-Toyota tranny fluid would be roughly equi valent to getting a blood transfusion with the wrong blood type. The WS fluid used in our trannies is a lower viscosity than the other mass-market fluids. If you want firmer shifts, get a replacement valve body or see if the tuning devices can alter shift line pressure.
 
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#48 · (Edited)
These guys ( IPT Performance Transmissions Torque Converters and Transmission Parts for Ford, GM, Chrysler, and Import vehicles make a valve body kit for the 5AT's in the FJ that will give you quicker, firmer shifts. DEWFPO

I have a tacoma with the A750F 5 speed auto trans....same as the FJ.

Anyways, I recently pulled it apart and sent my Valve Body to IPT....48 hrs later I had it back in the truck and filled up with synthetic AMSOIL Universal ATF. IPT recommended that fluid as did Gadget @ URD.

8 qts of fluid came out....so I filled up 8. Filling up the trans is easy. I pumped in 2 gallons in about 5 minutes with a penzoil fluid pump I got at a local auto parts store.



AMSOIL - Synthetic Universal Automatic Transmission Fluid (ATF)




The truck shifts a lot faster now and I love it.:rocker:

Here is the difference in shifting. Before and after...

Before.



After.

 
#38 ·
First of all, thanks to everyone for taking the time to write up your experience. It makes it a lot easier to tackle these things on your own.

I never saw a post on whether or not the strainer had filter media that should be replaced. Anybody know the answer?
 
#40 · (Edited)
First off I want to thank bartt your parts list for this job and instructions were spot on Hoses fit snug and didn`t need clamps or anything. This job is a easy as changing your oil. Here are a few pictures to see what I did


Heres the parts list 16 qts. of toyota ATF WS trans fluid.


3/8 ID clear hose hooked to the lower trans hose nipple coming out of the radiator


Same hose running out of the bottom of the truck into bottle measure the fluid coming out


1/2 ID clear tube taped to funnel and zipped tied to stay there while filling


same hose shoved in the fill plug about an inch


What the fluid looked like compared to new

Hope this helps this job is as easy as it gets
 
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#45 ·
Sanderhawk - glad you posted the photos, that really makes it clear.
 
#46 ·
Bartt thank you for making this job sound as simple as it is. I have heard so many horror stories about this that I almost didn`t do it. Then I read your post and you made it sound easy which it is. Your parts list and how to is top notch. Feel free to move the pics to the how to section or just leave them here. Thanks again Steve
 
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