Ford Power Stroke Nation banner

4R100/E4OD Trans Flush Procedure

150K views 74 replies 37 participants last post by  Mark Kovalsky 
#1 ·
I've done this alone. It's easier with a second person, and sometimes helps prevent spills.

1. Things you need to get started:

a. The transmission system holds almost 18 quarts of ATF, and you must waste a couple of quarts to be sure you get it all purged and replaced, so buy 20 quarts of MERCON or MERCON V ATF. You may use either conventional or synthetic, as long as it meets the above requirements. Don't use MERCON SP, it is not good for these transmissions. MERCON has been discontinued by Ford and is getting a bit harder to find. MERCON V has been changed to be compatible with these transmissions.
b. A 10 foot length of clear tubing and one hose clamp, sized to fit over your cooler hose. There have been different size cooler lines over the years, so check before buying!
c. If you don't already have a special funnel that fits into the transmission dipstick tube, then you will need one of those, too.
2. WARM UP THE TRANSMISSION!
3. Disconnect the transmission-fluid return line at the transmission - from where the ATF returns to the transmission from the cooler. This is the line towards the rear of the transmission. Clamp the clear tubing over the line that you removed from the transmission. This is where the old ATF from the torque convertor and coolers will come out.
4. This is where the second person comes in handy. One person starts the engine, while the other holds the line over the drain bucket. A clothes pin can replace the person holding the line in the bucket.
a. Run the engine until you see some air in the clear tubing. As soon as you see air shut off the engine.
b. While the engine is running in step 4a above, move the shifter through each position from P to 1, pausing about 5 seconds at each position. This will change some fluid that would otherwise be trapped in the valve body, accumulators, and clutches.
c. Refill through the dipstick tube with 6 quarts of new ATF.
5. Repeat steps 4a and 4c until you have added 19 quarts. When you add the 19th quart, stop. Don't run the engine again.
6. Remove the clear line and reconnect the cooler line to the transmission.
7. Check the fluid level and use the last quart of ATF to top off.
8. Properly dispose of the used transmission fluid.
9. Congratulate yourself! And your engine starter/killer person.

Now that we understand the basic procedure, let's muddy the water with the options:

Optional: Change the tranny filter.

2. After stopping the engine and before adding fluid, remove the pan, replace the tranny filter, and install the pan. Don't buy a new pan gasket. The original is reusable.

I replace the transmission filter every other fluid change. Note that Ford does not recommend ever changing the filter. I've opened filters with over 300,000 miles that were not even close to being clogged.

It just pulls out, there are no bolts that hold it. It is held in place by the pan. Make sure that the O-ring is removed, too. Sometimes it does not come out with the filter.

Optional: Drain the torque convertor. Add the following to paragraph 2 above:

If your truck was built before August, 2001, then you may have a drain plug in the torque convertor. If you do, then you can also drain the torque convertor as part of step 2 above. Some people think it is necessary, but I don't. Running the engine in the next steps will pump the fluid out of the torque converter. If your transmission was built after August 2001, you don't have a drain plug in the torque converter.
To drain the torque converter remove the shield (but NOT the upper right bolt - this one only needs to be loosened) and turn the flywheel until you see the drain plug. If you drain the torque convertor, be sure to replace the drain plug before you continue.
If you drain the torque convertor, then the old ATF won't come out of the end of the cooler line until the torque convertor is filled with ATF. So instead of waiting until you see air bubbles in the drain line in step 5a, run the engine for about 30 seconds while changing gears for step 4b, then cut off the engine.

Optional: Blow out the coolers. Add the following to step 3 above.

It's not necessary, but some folks want to get every possible drop of the old ATF out of the system before they add new ATF. If you drained the torque convertor, then you might also want to blow the ATF out of the coolers and cooler lines. If you have an air compressor, you can reduce the pressure to about 15 PSI, remove the cooler "hot" line from the front of the tranny, and blow air into that line. That will force the ATF in the coolers and lines out the cooler return line at the back of the tranny. DO NOT use air pressure of more than about 15 PSI! Then be sure to reconnect that line before you continue with paragraph 4.
 
See less See more
  • Like
Reactions: Dave mo
#8 ·
how often should you flush/change your tranny fluid?
 
#10 ·
Every 30,000 miles.

Mark,
Would I follow this same procedure for the 08-09 transmissions?
The TorqShift trans is different. It has an internal thermostat. The trans MUST be heated about 170F and kept there for the entire procedure or it will cut off 90% of the flow to the coolers and just recirculate the new fluid and mix it with the old fluid. So not only do you need to get the trans hot, you need to heat the new fluid that you're pouring in. There are heated flush machines that do this.

Also, the TorqShift requires MERCON SP. Any other fluid will kill the solenoids, and those seven solenoids are not cheap.
 
#11 ·
Alright i just noticed my tranny fluid is dark almost dark brown color realy no red at all, the truck has 215000 miles the fluid isnt burnt(well dosent smell burnt i think its just old) the tranny is running fine not a problem but what will cause the fluid to be that dark? I will do this flush and change the filter today. But just wandering if any of you have seen brown tranny fluid like that.
 
#13 ·
I would not run Schaeffers in the TorqShift. It is not MERCON SP, and that's going to be a big problem with the TorqShift.
 
#14 ·
can i use something other than sp in my 03 tranny? ford calls for SP only in this one
 
#16 ·
so my 03 is a torq shift? is that standard for an 03? I obviously know nothing about the 4R100
 
#17 ·
It is the standard transmission for the 6.0 motor. The 4R100 was the standard for the 7.3.

In 2003, you had the option of having either motor in the truck.
 
#18 ·
got ya......thanks.
 
#22 ·
My suggestion is to change the fluid. If the trans is in good shape the new fluid can only help it. If it's about to fail new fluid won't prevent it, but it won't cause it, either.
 
#24 ·
Here is some feedback from Brian at BTS on flushing the 4R100 Trans. Brian recommends to never run the pump dry. He recommends draining 8 qts out of the pan and then refilling it with 12 qts. Start the truck and let 4 qts pump out of the return line from the coolers. Repeat this process until you have run 20 qts through the system.
 
#26 ·
so any brand of fluid as long as it says mercon or mercon v ?

BOTTOMS UP!
Chris 0.
 
#27 ·
that looks like the one will have to check my links when i get home ..
i remember being posted by smokey wrench iirc.
 
#30 ·
I like your article on the flushing of the transmisions 4-R 100.
If you drain the transmission and the converter, do you put in the same amt of oil back in that you took out of transmission and converter? Or just what you took out of the transmission.

About using 15psi of to blow fluid out of cooler. If u do not do that method with the air if you just do it with the transmission fluid, is that about the same procedure as if you would use the air? Would it still push the old fluid out as you're pushing the new fluid in? Correct or not?
 
#31 ·
You can't put more than 8 quarts in at once or it will run out of the vent.

Blowing the coolers out with air or forcing it out with new ATF produces about the same results.
 
#33 ·
Just did this to my mother's 1997 Mercury Mountaineer, that had 1997 ATF to boot! The 4r70w had massive TC shutter at 45 mph. 13 quarts of Mercon V later and no shutter at all. My father could not believe it, the 121k trans now shifts better than it ever did.

Thanks again for posting this! :bowfast:

I will probably do this to my truck over the weekend.
 
#34 ·
Hi I need some help!! My 1996 f-250 4x4 460 cdi with a e40d transmission lost all foward gears going up a hill but I still have reverse, the transmission has never sliped before and has all shifted good, is there any thing that could be wrong other than the trans being toast. Thanks
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top