I just completed the Jmod on my 2006 CVPI with the 4R75E. I have only taken it for one short drive, but I can already tell that I love it.

At first, I was very concerned because upon removing the transmission pan, I found a very different looking valve body that what I've seen in pictures. The 4R75E has had some major revisions that changed the way it looks. All wiring and connectors have been replaced with a very simple and awesome black plastic piece that makes all of the connections. No exposed wires, no plastic clips, nothing. Just the one black piece that clips in place.

Sorry for the bad camera phone pic, but here's what's inside...



Then, when it came time to drill the holes, most were already larger than even the recommended Jmod sizes. I used a number 36 drill bit on all but the reverse hole, which I used a 43 on, and it came out great. That is similar to the MAX hp recommended sizes for the 4R70. The 1-2 accumulator spring was also different in that it had a spring inside a spring (similar to a dual valve spring) in the lower part of the housing. I removed both of those and the lower 2-3 spring.

Upshifts are crisp and clean now. So quick that at low throttle it shifts without even feeling/hearing the shift. High throttle shifts aren't neck snapping, but are quick enough that my drive belt now squeels in agony.

My only dissapointment is the downshift time is still really, really slow. I'm hoping that the custom program I have on order from BOC addresses that.

All in all, a day well spent. Oh, I should mention that it took me about 7 hours, but that included a trip to the hardware store to buy more 10mm sockets. I broke the two that I had trying to loosen the bolts on the transmission pan. Darn Ford mechanic that did my fluid change tightened those bolts WAAAY beyond the recommended 110 in/lbs.

That's AWSEOME![b][/b]

I'm gonna go out on a limb and say you probably wished you would have done this sooner!

Yes! I've had the fluid and gaskets for several months. Just been trying to work up the courage and find the time. From what I understand, 4R70 owners see a more dramatic change since some of the revisions basically give the 75 a Jmod from the factory. There are only 5 holes that get enlarged in the 75 and two of the holes are already really close. The other 3 are still only a few sizes smaller. I'm guessing that the Jmod on the 75 is only worth it if you also remove the lower accumulator springs. I doubt that the slight change in hole sizes in the separator plate makes much of a difference.

Now I just need to light a fire under my mechanics butt so he finds the time to do the rearend. I have 3.73's, a Cobra carbon traction loc, Moser girdle cover, and a complete rebuild kit waiting on him

I actually at first just drilled the separator plate first and was disappointed so then a week later went back in again and pulled the lower springs and was glad I did!

Are you the guy that just did a Reinhart tune?

No, I have a BOC tune on order and can't wait to upload

Did you install the OBX system yourself? I have it on my shopping list, but have been scared of the rusty manifold studs.

I took the car for another drive. I honestly think that anyone used to driving modern cars would not notice the Jmod. My car now just shifts without drama or delay. No different than a modern Honda or Toyota. They just shift and don't go to great lengths to smooth something that is normal.

The old slow, delayed shift was just a blast from the past that needed to go away.

The only remaining irritant is definitely the downshift delay. It still remains.

All my studs were rusty and most were pretty stuck. I had one broken one on the driver's side. After nearly stripping a few of the studs I decided F it and used a tiny welding tip on the torch and just put a small amount of heat on the end of each stud that was stuck and they came out easy as pie.

I think part of the problem with the slow response with the down shifting must be partly the work of the Blasted ETC and it's delay with pedal input.

I am hoping the BOC tune helps because I agree that the problem is in the program. My Dads 05 sport with ETC downshifts much quicker than mine...I think his factory program is better than mine.

The old Jerry Write-up is for 94-97. That's why your pictures look different.

The 4R70W looks like that from 98 onward.

The holes got bigger as new revisions were made.

Thanks Rizzo...you are the master. I was just surprised to find absolutely no electrical connections or regular wires and figured it must be a new thing. I've seen posts about people forgetting to re-connect things and figured they might be working on later transmissions. I'll have to pay more attention.

I didn't know where to post this and I wanted to throw this out there for others because I didn't see this anywhere...

When I did my Jmod I followed the instructions for firmer shifts and removed the lower 1-2 and 2-3 accumulator springs. That was a BIG mistake since I planned on getting a custom program.

After speaking with Lonnie at BOC, it is much better to leave those springs in if getting a custom tune because he can do the same thing with programming, but his will also affect the 3-4. If you remove the springs and custom program it for firmer shifts, 1-2 and 2-3 end up waaaaaay too firm.

I had to compromise and have him turn down the shift firmness so I am now stuck with too firm for 1-2/2-3 and a lazy 3-4.

No matter what was said, I always pick spring removal over line pressure increases.

People go nuts with that and start blowing up transmissions. The internal line pressure also has to pass the passages in the VB and they are not effected during the Jmod.

Relieve the resistance, Don't give it steroids.

I will also state in all my years here and many many PM's before and after with guys who get BOC tunes, You are the first to have this issue and the first to mention Lonnie and leaving the springs.

It was a huge shock to me. I scoured the Internet and relied heavily on your incredible advice and posts. When I contacted Lonnie and said my 1-2 and 2-3 shifts were so hard that passengers are complaining and it's barking the tires with light throttle he said "did you remove the lower springs?" and I said "yes" and he said "you weren't supposed to take those out."

On a side note, I can't wait to get the thing to the dragstrip. It shifts so quick and pulls so hard up top that I'm hoping for decent times.

I've watched Rizzo's video for this, and it is awesome and well done. I do have a question:
- Will this improve the pathetic slushy 3-4 shift I have with my '08?

may want to read up on this: High Performance OD Servo spring - F2VY7F201A. I did this upgrade on my '11 LX at the same time as Jmod and could not be happier. There is an excellent write up:

" Link 4R70W OD Servo,Valve Body and MLPS R&R - by Blue95"