Changing ATF: 7.3L PowerStroke Engine and 4R100 Automatic Transmission.
TheDieselStop staff is working on new truck FAQs to replace the outdated FAQs now accessed off the home page. The following is a draft of the tranny fluid change procedures for the 4R100 tranny that will be in the new FAQ. Feel free to reply to this thread with any suggestions you have to improve this article before it goes into the new FAQ.
Note: This article was revised on May 2, 2008. It was first written by Mark Kovalsky several years ago, so "I" in the procedures is Mark, not Smokey.
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FAQ
Transmission Maintenance - Do It Yourself (DIY)
Changing automatic transmission fluid (ATF) in a SuperDuty truck with 7.3L engine and 4R100 automatic transmission. (Will also work on earlier trucks with E40D transmission.)
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 V ATF. You may use either conventional or synthetic ATF, as long as it is rated MERCON or MERCON V. Your Owner’s Guide says to not use MERCON V, but Ford changed that in 2006.
b. A 10 foot length of clear tubing and one hose clamp, sized to fit over your cooler line. There have been different size cooler lines over the years, so check before buying! The metal part of your cooler return line is probably 3/8th inch outside diameter (OD) with a ferule on the end of it, so if you can find 7/16th inch inside diameter (ID) tubing, that will probably work great. If you use ½” ID, it will be a loose fit over the ferule and will need a good hose clamp tightened good to prevent it from leaking. So just in case, place a big drain pan under the connection. And some folks have reported they were strong enough to force a 3/8th inch ID tube over the ferule. If you try that, dipping the end of the plastic tubing in very hot water for a few seconds will make the job easier.
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.
d. If your transmission has ever been worked on by a Ford dealer, you probably have a Magnefine in-line filter in the "rubber" part of the cooler return line, near the front axle. If so, you should replace that filter every time you change the ATF. You can get one from your Ford dealer, or for about $15 from Magnefine Filters--Online Order Form. Your cooler lines are probably 3/8th inch, so you want the 3/8th size Magnefine inline filter.
2. Note: In cool or cold weather, be sure the transmission is up to operating temp before you begin. It’s not supposed to happen, but several members have reported ATF coming out the cooler bypass line instead of the cooler return line if they tried these procedures with a cold transmission. Also, in cool or cold weather, keep the new ATF in the house so it’s around room temperature of about 70º F. when you pour it in the transmission.
3. If your pan has a drain plug, drain the pan, then replace and tighten the drain plug. If it doesn't have a drain plug, skip to step #5.
4. Pour 7 quarts of new ATF into the filler [dipstick] tube.
5. Disconnect the transmission-fluid return line at the transmission - from where the ATF returns to the transmission from the cooler(s). This is the line towards the rear of the transmission. This is where the old ATF from the transmission, torque converter and coolers will be pumped out. Clamp the clear tubing over the line that you removed from the transmission.
The following is a drawing of the 4R100 transmission, seen from the passenger’s side of the vehicle. The arrow at #2 shows the banjo connection where the cooler return line and the cooler bypass line connect to the rear of the transmission. The arrow at #4 shows where the “hot” line and the cooler bypass line comes out of the banjo connection on the front of the transmission. (The cooler bypass valve is near the banjo connection at the front of the transmission, in that bypass line that runs between arrows #4 and #2.)
6. 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 at idle RPM until you have around 1.5 gallons in the drain bucket, then you should see a big air bubble in the clear tubing. Ignore tiny bubbles. As soon as you see a big air bubble, shut off the engine. Then double-check the amount of used ATF in the drain bucket. You should have around 1.5 gallons. If you have much less than 1.5 gallons, then you probably killed the engine too soon, so crank the engine and pump out some more old ATF.
b. If you drained the pan in step 3 and poured in 7 quarts of new ATF in step 4, then while the engine is idling in step 6a 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. If you poured in 7 quarts of new ATF in an earlier step, then refill through the dipstick tube with 6 quarts of new ATF. (That's 13 quarts total so far). If you have not poured in any new ATF yet, then pour in 7 quarts of new ATF, for a total of 7 quarts so far.
7. Repeat steps 6a and 6c until you have poured in a total of 19 quarts of new ATF (7 + 6 + 6).
8. Remove the clear line and reconnect the cooler line to the transmission with 20 lb/ft torque.
9. Drive the truck several miles to get the transmission up to operating temperature. Then check the fluid level and use the last quart of ATF to top off.
Note: You should always check the ATF level when the transmission is up to operating temp – not when it’s cold. The cold marks on the dipstick are not very reliable. When first filling the transmission, use the cold zone on the dipstick to get close to the right amount of ATF in the transmission. But for topping off, do it with a hot transmission using the hot area of the dipstick. When you get done, you want the transmission full, but not overfull.
10. Properly dispose of the used transmission fluid.
11. Congratulate yourself! And your engine starter/killer person.
12. Then get back on TheDieselStop and tell us your "lessons learned" for those that follow you down the DIY road.
Now that we understand the basic procedure, let's muddy the water with the options:
Optional: Change the internal transmission filter. Revise paragraph 3 above to read:
3. Drain the pan, remove the pan, replace the transmission filter, clean the inside of the pan and clean the reuseable gasket, install the pan, then replace and tighten the drain plug. Torque pan bolts to 11 lb/ft.
If your pan doesn't have a drain plug, you remove and drain the pan at the same time. This might be a messy job, but most tranny pans on other vehicles don't have a drain plug, so you won't be doing something the pros don't do routinely.
Don't buy a new pan gasket. The original is reusable.
The pans for the 4x2 and 4x4 drivetrains are slightly different, so the internal transmission filter is also slightly different. So be sure you buy the correct transmission filter for your drivetrain.
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 converter. Add the following to paragraph 3 above:
If your truck was built before August, 2001, then you may have a drain plug in the torque converter. If you do, then you can also drain the torque converter as part of step 3 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.
If your torque converter does include a drain plug, then 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 converter, be sure to replace the drain plug, and torque it to 18 to 20 lb/ft before you continue.
If you drain the torque converter, then the old ATF won't come out of the end of the cooler return line until the torque converter is filled with ATF. So instead of waiting until you see big air bubbles in the drain line during your first iteration of going through in step 6a, run the engine for about 30 seconds while changing gears for step 6b, then cut off the engine.
Optional: Blow out the coolers. Add the following to paragraph 5 above.
It's not necessary, but some folks want to get every possible drop of the old ATF out of the system before they pump new ATF through the system. If you drained the torque converter, 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 line pressure to about 15 PSI, remove the cooler "hot" line from the front of the transmission, 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 transmission. DO NOT use air pressure of more than about 15 PSI! Then be sure to reconnect that line before you continue with paragraph 6.
Last edited by SmokeyWren : 02-05-2009 at 01:07 PM.
Reason: Tweaks per Mark Kovalsky's suggestions
TheDieselStop staff is working on new truck FAQs to replace the outdated FAQs now accessed off the home page. The following is a draft of the tranny fluid change procedures for the 4R100 tranny that will be in the new FAQ. Feel free to reply to this thread with any suggestions you have to improve this article before it goes into the new FAQ.
Hey Smokey
It's been over 7 months now, how much longer till this makes it to the new FAQ's?
It's been over 7 months now, how much longer till this makes it to the new FAQ's?
Don't hold your breath. The administrators for Autoforums.com, the new owners of TheDieselStop, have had some firings and some hirings. The latest bunch are great guys, but their plate is running over - they have over 100 websites under the Autoforums umbrella. They haven't told us when they might get around to revising the FAQs on TheDieselStop from the old system off the home page to the new forums-based system. The previous bunch of administrators were actively working on the revised FAQs, but they are gone now. So in the meantime, the volunteer moderators will post the latest changes to the FAQs in the new FAQ forums, such as this one.
Feel free to reply to this thread with any suggestions you have to improve this article before it goes into the new FAQ.
My only suggestion on the tranny flush procedure would be to recommend cleaning the pan and gasket before re-installation.
I know this seems like a "no brainer", but some folks just do what they're told. A film of grime can accumulate in the pan. It needs to be perfectly clean. A solvent or cleaner works good. And a re-usable gasket and gasket surface free from oily residue is less likely to leak. I use something like carburator cleaner to wipe it off.
Last edited by SmokeyWren : 02-05-2009 at 12:12 PM.
Additional pointer for anyone doing this for the first time:
A bit of fluid might come out of the bypass banjo a few seconds after the truck is started and/or when switching through the gears. Dont just assume the bypass is active. Let it run for a few seconds and see if it stops. I turned off the truck before I realised it would stop and wasted the 7 quarts driving around getting it "Back" up to temp.
After reading the procedure for changing the transmission fluid and seeing some of the comments about the bypass value engaging causing ATF to spill out I was wondering if it makes sense to just dump the fluid from the output cooler line instead of the return line.
If you connected the hose to the output line before the coolers, then there should be absolutely no back-pressure on the bypass value. Assuming that your valve is working properly and that the unit is at operating temp, then this should be a easy run.
Also, how do we know that the bypass valve is pushing all of the fluid toward the coolers? I thought that this was a temperature operated switch and that it slowly opens depending upon temp. Seems to me that there will be some mixing of old and new fluid in the pan because of this.
a. Run the engine at idle RPM until you have around 1.5 gallons in the drain bucket, then you should see a big air bubble in the clear tubing. Ignore tiny bubbles. As soon as you see a big air bubble, shut off the engine. Then double-check the amount of used ATF in the drain bucket. You should have around 1.5 gallons. If you have much less than 1.5 gallons, then you probably killed the engine too soon, so crank the engine and pump out some more old ATF.
b. If you drained the pan in step 3 and poured in 7 quarts of new ATF in step 4, then while the engine is idling in step 6a 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. If you poured in 7 quarts of new ATF in an earlier step, then refill through the dipstick tube with 6 quarts of new ATF. (That's 13 quarts total so far). If you have not poured in any new ATF yet, then pour in 7 quarts of new ATF, for a total of 7 quarts so far.
7. Repeat steps 6a and 6c until you have poured in a total of 19 quarts of new ATF (7 + 6 + 6).
8. Remove the clear line and reconnect the cooler line to the transmission with 20 lb/ft torque.
9. Drive the truck several miles to get the transmission up to operating temperature. Then check the fluid level and use the last quart of ATF to top off.
Maybe this is just me having a brain fart in the way I'm reading.... But in step 7, if you repeated 6A, continously pouring in 19 quarts, then reconnecting the cooler line - then driving the truck you will have pumped all 19 quarts into the waste bucket, then connecting the line and then attempting to drive it. I don't see a "final" fluid refill in the steps.
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'99 F250 CC-SB 4x4, AFE Stage 2 intake with Pro-Guard 7, Dieselsite coolant filter, DiPricol Full gauges, AIC, On board air + Buell emergency series air horns, Striker turbo timer, Striker I module, Cyclops anti-theft module, TC lockup and 6.0 trans cooler.
But in step 7, if you repeated 6A, continously pouring in 19 quarts, then reconnecting the cooler line - then driving the truck you will have pumped all 19 quarts into the waste bucket, then connecting the line and then attempting to drive it. I don't see a "final" fluid refill in the steps.
Read it again:
"7. Repeat steps 6a and 6c until you have poured in a total of 19 quarts of new ATF (7 + 6 + 6)."
By the time to get to step 6a, and assuming your tranny pan has a drain plug, you have replaced the drain plug, and poured in 7 quarts of new ATF, so the only ATF going out of the system will be pumped out in step 6a.
The first time you do step 6a, you pump the pan dry, then you pour in 6 more quarts in step 6c, for a total of 13 so far.
The second time you do step 6a, you pump the pan dry, then you pour in 6 more quarts in step 6c, then you STOP. You have poured in 19 quarts total, so stop doing that step and go on to step 8, which is to button it up.
"8. Remove the clear line and reconnect the cooler line to the transmission with 20 lb/ft torque. "
Including the procedures for doing the flush when your tranny pan doesn't have a drain plug complicates the writing. But that's what Mark wanted, so that's what Mark got.
If you were going to re-write it, and complying with Mark's requirement to include tranny pans without a drain plug, how would you word it?
Last edited by SmokeyWren : 09-11-2009 at 06:29 PM.
Ok, wording makes sense now... after you pour in the 19th quart, you don't pump any more out the return line for the flush. I guess I really shouldn't contemplate hard on thinks like that after just waking up mid day!
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'99 F250 CC-SB 4x4, AFE Stage 2 intake with Pro-Guard 7, Dieselsite coolant filter, DiPricol Full gauges, AIC, On board air + Buell emergency series air horns, Striker turbo timer, Striker I module, Cyclops anti-theft module, TC lockup and 6.0 trans cooler.
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Automatic Transmission Engineer 1988-2007
Trans fluid change, bypass coolers?
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