...for the 2001 – 2003.5 Ford F150 (but this may work for other vehicles with the 4R70W)
This writeup provides
picture-based instructions for safely and effectively exchanging the
transmission fluid in a F150 4R70W transmission with new fluid. There are
myriad web pages on the internet for servicing the 4R70W, as it is the automatic transmission commonly
used in Mustangs and in Crown Victorias, but very few resources when it comes
to servicing the transmission in a truck.
I was personally frustrated
with the lack of any useful information on performing the fluid change
procedure, so I researched and researched and put together this guide. When I say "useful information", I mean something more than an article written entirely in text and with no explanation of the different parts of a transmission. I
believe that anyone with a general knowledge of automotive handywork should be
able to do this job on a weekend afternoon.
Before we proceeed, I should
explain what exactly is being done in this procedure since I am not simply
regurgitating the information in the Haynes manual. The 4R70W in the ’01-’03.5
(Heritage) F150 specifies approximately 14 quarts of Mercon V transmission
fluid. Under normal circumstances, approximately 4.5 quarts of MerconV will be
present in the actual “fluid pan” of the transmission, with the remaining 9.5
quarts in the torque converter and in the cooler lines. If you are not familiar
with the way this transmission is designed in the F150, refer to the diagram
(Please excuse the crudeness of my drawing)
Basically, the transmission
utilizes a closed-loop cooling system where the transmission fluid is pumped
forward of the vehicle to the radiator where it is cooled via the engine fan
and airflow when driving down the road. The cooled transmission fluid then
returns to the transmission where it is utilized in the valve body and torque
converter to keep the vehicle moving forward.
The Haynes manual suggests
that you drop the transmission pan to replace the fluid, filter, and clean the
magnet. While this does allow you to replace the filter and clean the magnet,
you do very little in terms of changing out the fluid since most of it resides
in areas of the transmission cooling system that are not accessible. In order
to fully exchange the old transmission fluid in the system, you must either empty
the torque converter (those of you with ’01 F150s (up until Aug/Sep of 2001)
will be able to do this) and purge the cooling lines, or utilize the pump
system to capture the old fluid at some point in the closed system.
Since my truck is a 2002, I
was not able to access a drain plug in the torque converter. I did some
research on some of the more popular forums that discuss the 4R70W (TCCoA,
F150online, Stangnet) and found some people mentioning that they were able to
use the cooler lines to perform a fluid exchange. I spent about a week
contemplating my options and looking around at the transmission and the cooler
lines before I committed to purging the fluid via the cooler RETURN line AT the
transmission. As you will see below, this turned out to be fairly easy and
easily beats dropping the transmission pan (full of fluid) and getting the
famous “ATF shower”. You'll also save about $100 that most dealerships charge to hook up a T-Tech machine to perform the flush procedure.
Before you begin…
should have some prior experience on DIY maintenance work. You should be
familiar with the terms used in this writeup and understand what is meant
when direction is specified on a vehicle (forward, rear, driver-side,
your truck. If your truck has a tow package of auxillary transmission
cooler, this will change the fluid quantities I specify below for a stock
not required, it would be helpful to know the “cold fill” mark on your
transmission dip stick. Some dip sticks (not specifically for the 4R70W in
a F150) have a cold-fill mark, but mine did not. This saves some time at
the end of the procedure.
- At a
minimum, 14 quarts of Mercon V specification transmission fluid (more
fluid = more thorough flush). Note that Mercon V is not a brand, but a
lubricant characteristic specification created by Ford Motor Company. What
this means is that you do NOT have to get "Motorcraft Mercon V". Frankly,
you would be fine using Wal Mart’s Supertech Multi-Vehicle ATF or even
Schaeffer’s ATF. As long as the fluid meets or exceeds Mercon V, you will
bucket, at least 5 quarts in capacity. I found mine at Lowe’s in the aisle
with buckets and containers. I believe these are supposed to be used for
mixing paint, but they work just fine.
internal diameter clear vinyl hose. You can also find this at Lowe’s, near
the aisle where PVC pipe is sold. I found a pre-measured package that was
only a few bucks and turned out to be a lot more than I needed. You can
always use the rest later for other automotive maintenance procedures. The brand and model for mine was: WATTS SVIG10 42143610 Clear Vinyl Tubing 1/2 in x 3/8 in x 10 ft
or clamp. This will keep the vinyl hose pointing into the bucket.
5-gallon bucket or multiple smaller containers for holding the old
transmission fluid. Match the size of this bucket or containers with the
number of new quarts of Mercon V that you plan on using.
Box-End Wrench (the longer the handle, the better)
Box-End Wrench (the longer the handle, the better)
socket and socket wrench(for the transmission pan bolts)
Torque Wrench (where 120-130 in-lb rests in the middle of the torque
and/or work light
funnel (to be used for re-filling the transmission fluid)
cleaner/Carb Cleaner (to clean out the transmission pan)
- (Optional) Replacement
4R70W transmission filter. (Part No. F6AZ-7A098-A)
Creeper for easily getting under the truck.
Junk cardboard for catching any fluid drips.
to spend around 2-3 hours on this procedure. If you can get a helper
person, you can probably finish in 2 hours. Always expect the first time to take longer. Follow up procedures should go a lot quicker.
the vehicle to cool FULLY before beginning the procedure. You do NOT want to burn your hands against a hot transmission pan or against the heat shields.
- Park the vehicle in a cool, level location. Set
out all of your materials beforehand so you don’t have to waste time
(16 quarts of Mercon V lined up for use. I got this during a special at Pep Boys so I only paid $40 for all 16 quarts)
- When the vehicle has fully cooled, put on your
safety glasses and slide under the vehicle on the passenger side,
approximately where the transmission will be.
- Position your head/eyes to the space between the
transmission and the catalytic converter. You are looking for 2
aluminum/steel hard lines that are bent 90* and enter the transmission via
some screw fittings.
- The UPPER fitting/line is the RETURN line. This
is the line where fluid will come out after it has been cooled in the
radiator. You need to loosen the 5/8” nut to make the line open where you
can slip the vinyl hose over it. Use the ¾” box-end wrench to keep the ¾”
nut in place while you use the 5/8” wrench on the smaller nut to loosen
it. I highly recommend you do it this way because I originally just used
the 5/8” wrench and was actually unscrewing the larger ¾” fitting from the
transmission. Not good, but no harm done. The smaller nut requires very
little to be loosened and will spin freely when completely loosened.
- Slide the smaller 5/8” nut back and expose the
end of the cooler line.
- Position your hands so that you can slip one end
of the 5/8” I.D. hose over the end of the cooler line as far as possible.
Route the tubing around so it does not kink anywhere. Allow the excess
tubing to hang down to the ground and cut the tubing where it meets the
ground. This will allow you to have enough to route the other half of the
tube into the marked quart bucket.
- Use the clothespin or clamp to direct the tubing
into the bucket. Position the bucket so that you can easily see the quart
markings (point the markings toward the driver side if you are working
solo). Optional – place the junk cardboard under the bucket so that you do
not get any spills onto your garage floor.
- Get into the cab of the truck and start the
vehicle. Immediately, look below the truck at the bucket and wait for the
transmission fluid to begin flowing. You may wait 10-20 seconds for the
fluid to fully travel through the lines and exit out. The transmission
fluid will fill the bucket quickly, so keep an active eye on when you
begin seeing bubbles in the vinyl line, as this indicates that the bulk of
the transmission fluid has been sucked out of the transmission pan. On my
vehicle, almost exactly 4 quarts was extracted before I started to notice
air bubbles in the vinyl line. When you see the bubbles (and you may even
hear a difference), immediately turn the truck off. You have now emptied
the bulk of the transmission fluid in the pan.
(Almost exactly 4 quarts extracted from the cooler return line before I started to notice air bubbles in the hose)
- Empty the old fluid into your 5-gallon bucket
and set the bucket aside. Get under the truck and leave the vinyl hose
connected, but move it out of the way. I found a small spot in the frame
cross-member where I was able to tuck the hose away.
- Use the 10mm socket end to loosen all of the
transmission pan bolts. When you begin removing the last few bolts, the
pan may want to start dropping, so keep it supported. The pan itself has
some weight, but will be considerably lighter since it does not contain an
entire 4.5-5 quarts of Mercon V.
- Loosen the remaining bolts and slowly lower down
the transmission pan. It will still contain some fluid, so be careful and
set the pan aside. The filter may or may not drop along with the pan. You
need to take it out either way.
- Drain the rest of the old fluid inside the pan
into the 5-gallon bucket. I think I had around .5-.75 quarts of fluid left
in the filter and in the pan.
(Fluid that remained in the pan after the initial extraction along with old filter and sludged up magnet)
- Remove the magnet from the pan and clean it with
a towel. Set the magnet aside.
- Drain the old fluid in the old filter into the
5-gallon bucket and toss the filter aside.
- Use carb cleaner or brake cleaner to clean the
inside of the transmission pan.
- Use a paper towel to clean up the reusable
transmission pan gasket.
- Place the clean magnet inside the clean
transmission pan, set the reusable gasket onto the clean gasket surface.
The holes in the gasket will line up with the pan only one way. While you have the chance, clean all the bolts that hold the transmission pan up. Use a degreaser to clean the threads.
- Go under the truck and install the new
transmission filter. The internal neck of the filter will slide into the
opening on the underside of the transmission.
If you find it difficult to install the new filter, it's possible that the old orange o-ring is still inside the transmission body. The picture below shows the culprit o-ring that can sometimes separate from the old filter. (Thanks Henry)
- Install the newly cleaned transmission pan, and
use a cross-bolt pattern to torque all the bolts to 120-132 inch-lbs.
- Retrieve the vinyl hose that you tucked away and
point it into the measured bucket using the clothespin or clamp.
- Fill the transmission with 4 or 5 quarts of NEW
(You will need to use a long, narrow funnel to fill the transmission fluid from the dipstick tube)
- Turn on the vehicle and watch as old Mercon V
quickly fills the bucket. Wait until 1-2 quarts is filled and then turn
off the truck.
- Refill the transmission with NEW Mercon V in the
same amount that you just extracted.
- Empty the measured bucket, if required.
(This is the total amount of fluid that was extracted from the transmission -- almost enough to fill a 5 gallon bucket!)
- Repeat steps 22-24 until you have gone through
13 quarts of Mercon V.
- Sometime during the exchange process, you can
shift the vehicle out of Park and into a different gear to flush out old
fluid in the valve body. Keep the brake pressed when you are in a
different gear and only stay in gear for about 5 seconds. This part is
where having a partner is helpful because someone can watch the fluid
filling the bucket. I would try not to extract more than 3 quarts at a
- Disconnect the vinyl hose, and re-connect the
cooler line into the ¾” nut. Use moderate torque on the 5/8” nut as it
does not require a whole lot to lock again. The truck may have warmed up at this point, so you can break until it cools as the exhaust will have gotten fairly hot from the constant start ups.
- Clean up all tools and items under the truck and
set them aside. Start the truck and let it idle in park for a few minutes.
This will allow the new fluid to cycle through the system. Watch for
leaks. If there are no leaks, wipe up any transmission fluid that has
leaked to the ground.
- Get in the truck and shift into gear and move it
back (or forward) to test if Reverse, Drive, Neutral, 1, and 2 work. Take
it easy and slowly work the truck back and forward. On some gears, you may
experience a slight delay in movement while fluid fills the valve body.
- Get out, check for leaks. By this time, the
engine and transmission should be warmed up, so check the transmission fluid
dip stick to see if you are in the hash marks. Add some fluid if needed,
but only a little at a time.
- When the truck is moving in all gears, there are
no leaks, and you are set on the fluid level, drive the vehicle around the
block to test everything.
- In the next few days, monitor the transmission
fluid level as it will settle and may drop in level as fluid routes its way into
all the transmission areas.
Questions? Comments? Concerns? Feel free to contact me at wchong4 [at] gmail [dot] com.