Common Fix For 4r55e / 5r55e Transmissions With A Bad Separator Plate And Valve Body Gasket

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In this article I hope to address the common fix for the 4r55e / 5r55e with a bad separator plate and valve body gasket.

Some of my pictures are not the greatest but they will get the point across. If you have any questions please feel free to contact me.

Let’s get started. You will need the following items:

– INCH POUND Torque wrench

– t-30 torx

– metric sockets

– trans fluid (7 total quarts) (I supplemented a quart of Lucus transmission additive for one quart)

– Trans Filter Kit

– New separator plate (I will explain later)

– TSB replacement (mine was kt3l5p-7m203-ja)

Petroleum jelly

– Pick and Needle Nose Pliers

– Card board (again, I’ll explain later)


I would encourage you to go to a Ford dealership and get the separator plate because the gaskets
are bonded to it and it’s only about $14. The bonded gaskets should eliminate
the blow out problem. I also recommend having a Ford dealership plug in the VIN so you can
address a couple TSBs while you’re in there. My total investment was around $100 and
maybe 5 hours of labor.

Make very sure that you are keeping all parts clean and installing clean bolts. The
smallest dirt can make a valve stick!


First you must get that old transmission pan off. Pull the bolts and leave a couple in so you
can direct the flow of trans fluid towards the pan. Good luck, you will need it.

Then after you get the pan off you can set it aside and pull the filter, again you will
get a nice shower of fluid. You should get a new bolt with the filter so you should be
able to discard this bolt. I would recommend doing this so you don't get it messed up
with the others later.
Once the filter is off you can make a template of you valve body bolts. This is critical
because there are something of 6 different length bolts. Here is my crude but
effective template.

Now that you have the template you can remove the wiring harnesses of the
solenoids. Pull the wires straight down off of them. You do not need to remove any of
the bolts to go this. Then lay the wires off to the side so you don't get them
entangled in something else. Below is a picture of the wires attached:

In this photo you can see the gold bolt which holds a bracket on. DO NOT TAKE ANY
OF THE GOLD BOLTS OUT AT ANY TIME during this fix. these hold the solenoids in. If
one comes loose fluid can bypass the o-rings causing the trans to not shift.
Now that you have the wires off you can see the 24 bolts that have to come out to
get the valve body off. Here is the photo showing the torque pattern but it will show
you where all 23 bolts plus the one for the filter are.
Below is a picture of my template with the bolts in it:

I’d recommend leaving the 2 bolts in the center in so they can support the valve
body. There are also 4 bolts on the reverse servo that need to come out. (this is the
round hole you see in the picture with the 4 bolts in a square pattern) These hold the
cover on as well as the servo in, so it might come out. If so just sit it off to the side
where it will stay clean. the cover has a paper gasket on it and I didn’t need to
replace it but I did anyway. I would just recommend reusing the old gasket.

Now you must remove a couple of bolts on the side of the trans that hold the manual
detent lever spring. Note the orientation of the spring lever. I have also circled the
gear selector valve and how it attaches. You need to make sure to get this back on
when reinstalling the valve body. (left circle) and the right circle is the bolt holding
the manual detent spring lever. You may remove these both and lay them off to the
side and there should be a place in the template for the bolt.
How you should be ready to pull the valve body down. make sure you have of the
pans ready because these is a couple of quarts of fluid ready to make their
appearance. Pull the last couple of bolts and remove the valve body. Bring the
valve body straight down and make sure to not set it on anything dirty.
Once you have the valve body out you can go to the work bench and spread some
towels and begin the fun part. At this point you should be able to see where the
gasket is blown out like mine below.

Once you are on the work bench you can remove the three bolts that hold the
separator gasket on. I cannot stress enough that this is where you need to be
careful. There are check valves in the valve body and you want them to stay there,
so keep the open valve body face up. Remember when you pull the separator
plate off you need to lift slowly and gently because there are 2 pressure release
valves inside that might be stuck to it and you don't want to lift these out. Below are
photos of the t-30 bolts, separator plate and the valves locations

Now you should have the old separator plate off and you can toss this if you
purchased a new one. How you can address the ford TSB with the blow off valve.
Below are pictures of how and where to install it.
To uninstall the old valve you will see where I point out the retainer, this lifts out and
then you should be able to work the old valve out. It can be a pain but don’t be too
mean because you do not want to scar the valve body in any way so take your time.
The new valve will install in the hole and there is a dimple on the valve that needs to
be oriented straight up. none of my pictures turned out good enough with the dimple
but my instructions page from ford did. it is below. When installing the new valve
you can slick it up with petroleum jelly. This will lube it enough that you can work it
in. Do not force it in, if you work it you can slide it in very easily. then it should be
flush. Then install the new retainer.




Now relax, the hard work is finished. All that is left is to remove some parts for some
reason which ford did not specify. There is one spring and a screen to remove. The
instructions in the TSB will explain this better, but here is an idea. You can throw
these parts away.

Now its time to button up! Go ahead and put the new separator plate on and install
the 3 bolts. Torque these to 71 INCH POUNDS and then retorque them to 97 inch
Now crawl under the truck and look up inside the transmission. There was a huge
chunk of old gasket stuck in one of the galleries of my transmission. I ended up following
every oil path with a light to see if there were any other pieces.
next you can put the valve body back on and put the bolts back in. this is where the
template comes in very handy. hand tighten everything until all bolts are in, this will
ensure that everything is aligned nicely. After you’re sure all the bolts are in and
started you can start torquing the bolts in sequence. You will want to torque to 71
inch pounds for the first trip around, and then up to 97 (I did 95) on the second
round. Torquing of the valve body is critical. You must do it in order and have a
uniform torque. Below is the torque pattern:

Now you can reinstall the reverse servo and cover. Then torque the bolts to 80 inch lbs and then to 115 inch pounds.
Next reinstall the manual detent return spring and make sure ur valve is installed correctly:

Now you should be ready to plug the wires back in on the solenoids. than you may
install the filter. Make sure to clean the pan really well before putting it back on. The
magnet should be cleaned and have no gunk on it.
Install the pan and than add oil. My transmission took 7 quarts of oil so be prepared for that.
Let the truck warm up and cycle the gears before you drive!
Overall I would rate this project a 7 out of 10 (10 being really hard). this is a time
consuming project and you must be able to pay attention to details. GOOD LUCK!!!
p.s. I would like to thank HUSKER for letting me use his garage to fix my trans and take time to picture this fix.

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