Earlier this week, my buddy Rob calls me and says his truck suddenly lost Overdrive. My first though was he might have burned the OD band which is common on this model transmission, however Rob reports the fluid is full and in good condition. A quick google search and I quickly find 3 pages of web articles talking about this, so I am fairly confident this what has happened to Rob's truck.
I discover it is common on the 2004-2008 model F-150s for the OD servo snap ring to break and the debris gets wedged in the OD Servo Regulator valve in the valve body, which causes loss of Overdrive.

This link is one of the better articles I found;

04 F150 Lost overdrive, servo clip broke (pics) - F150online Forums

This guy made a youtube video about his repair;




Armed with this information, Rob and I met this saturday to pull the pan and valve body to see what was going on. Sure enough, the OD servo snap ring was broken and a piece was wedged in the OD Servo Regulator valve.











some how we forgot to take pictures of the piece that was wedged in the valve body, but I found some in another post that was identical to what we saw.





Since we had the valve body off, I decided to use this opportunity to do some valve body modifications, commonly refered to as the J-mod. If you are not aware of the J-mod, read here; TCCoA Tech Articles
This article was written by a Ford transmission engineer Jerry Wroblewski and it outlines how to improve, modify and strengthen the AODE/4R70W transmission. pages 13 and 14 discuss the mechanics of the valve body and what modifications to make. while this article was written in 2000, there is still a lot of useful information, but be aware some of the part #s have been discontinued and most have superseded by Ford.
Jerry has also updated Valve body calibration for newer model transmission (2001+)

"Ignore what the article says and do this...

Hole #2 is the intermediate clutch feed (1-2 shift). Make this hole in the .100"-.110" range. It should be .081" in your plate right now.
Hole #10 is the reverse clutch feed. Totally optional. If you want it to engage into reverse faster when you move the lever, open this up to .093".
Holes #4 & 5 are the direct clutch feed (2-3 shift). Open both of these holes up to .100"-.110".
Holes #9 and 11 are the forward clutch feed (4-3/4-2 shift). Make both of these .100-.110" as well.

So, it looks like you need a drill of around .100" and you should be good. When you open up holes 4&5 make sure the hole in the gasket between the
separator plate and valve body casting, is large enough. These holes are a little small.

-Jerry"



With valve body removed and disassembled, we cleaned everything. Base on Jerry's information, I drilled separator plate Holes #2, #4, #5, #9 with a 7/64 drill bit. On this 2004 model transmission, hole #11 was already larger than the 7/64 drill bit, so I left it alone.
Since Rob had been complaining about how slow reverse was to engage, when shifting from park to reverse, I used a 7/64 drill bit on hole #10 as well.

Once the valve body was cleaned and separator plate was drilled, I updated several shift valves with improved valves from Sonnax. This was based on the information in this article; OD Servo/Spring, Solenoids, MLPS Replacement *DUW* - Crownvic.net

I installed an updated Main Pressure Regulator Valve (Sonnax #76948-09) Read here; Sonnax - Aftermarket replacement transmission, torque converter, and high performance automotive parts

To compliment the updated Main Pressure Regulator Valve, I also installed an updated Pressure Regulator Boost Valve & Sleeve Kit (Sonnax #76948-02K) Read about here; Sonnax - Aftermarket replacement transmission, torque converter, and high performance automotive parts

I also installed an updated OD Servo Regulator Valve. This is the valve where the piece of broken snap ring was wedged in. Sonnax #76948-29K read about it here; Sonnax - Aftermarket replacement transmission, torque converter, and high performance automotive parts

Both the Pressure Regulator Boost Valve and the OD Servo Regulator Valve consist of a small shuttle valve that ride in the larger/outer valve called a sleeve. These valves oscillate in the sleeve and become worn, which causes loss of pressure and "lazy" shifting. These improved Sonnax valves are a harder material and more resistant to wear. Both the valve and sleeve are machined to higher tolerances so they fit better within each other and in the bore of the valve body.







The same article about the updated shift valves also talks about softer OD servo spring (F2VY-7F201-A) which is now obsolete from Ford. I was able to find a few springs still available through discontinued parts vendors and ordered 2. This softer spring allows the OD servo to apply faster and more firmly. Since I wasn't sure what size the OD servo was (some transmissions had the 2.5" servo) and I wasn't sure what shape servo would be in, we opted to buy a replacement 2.7" OD servo.
The original servo showed some wear from where it was beating up and down on the broken snap ring, we opted to installed the OD servo. New OD servo, softer OD servo return spring and new snap ring.
BTW, the part # for the new OD servo snap ring is F2VY7384B.





With the new OD servo parts installed in the case, the Valve body cleaned and reassembled with the new valves and gaskets, we put everything back together and torqued the valve body to the case, installed the transmission harness, new filter and bolted on the pan.





After adding 6qts of fluid, I decided to have Rob start the truck and run it through the gears. Good thing we did this because the OD light started flashing immediately, we found DTC P0740 and P0743 set, both are for TCC circuit faults. Knowing this was nothing mechanical, we jacked the truck back up and pulled the pan to remove the transmission harness. With the harness removed, I found a broken/bent electrical contact for the TCC solenoid causing it not to make contact. I also discovered the plastic body of the harness was cracked.
A quick phone call to the local dealer and they had a new harness in stock. Since the part was available, we opted to replace it.

New harness installed, pan back on and bolts torqued properly we filled the transmission with 10 qts of Mercon V fluid and went for a test drive.
once it was up to normal operating temp, the flogging began, the transmission shifted crisp and firm at light to normal throttle and OD works again!

Since the truck was already tuned with a SuperChips tuner, the line pressure was already raised above stock and the 1-2 shift above 50% throttle was down right violent, the shift was so hard I thought the dash was going to fall off in my lap!. I hooked up the SuperChips tuner and set the line pressure back to stock for the 1-2 shift, this made it bare able.
pleased with our work, we topped off the fluid with one more Quart of trans fluid, check for leaks (found none) and cleaned up our tools and work area.

 

Cool. An instruction class with pictures and parts for "how to" do a performance transmission build, minus $600+ in labor! This needs to go in the "how to" files.

 

next time I build one, i will make a video.

 

How did the jmod hold up? I have an 04 stx 4x4 (new body style) and the OD just went out. Hopefully its just the clip but I figured if I'm already in there replacing the clip I could do the jmod if it's worth the hassle and works on F150s like it does the Crown Vics.

Anybody else do the jmod with success? Also, are there any extra parts that must be purchased or are they just recommended to freshen things up? It seems like only drilling the plate and gasket is required but I can't tell for sure, need to do more research.

Thanks for the help.