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#1152107 - 03/22/07 03:50 AM "J-MOD" - AODE/4R70W transmission upgrade tech
dRock96Marquis Offline

Posting Addict

Registered: 02/22/05
Posts: 24394
Loc: Maryland
These posts contain information on upgrading the AODE/4R70W/4R75W/4R70E/4R75E transmissions used on 1992.5+ up panthers for improved performance and durability.

The first post (below) contains general information on the "J-MOD" modifications and some notes for 1998 and newer model owners who will be performing the upgrade.

The second post provides reviews of some of the possible accumulator spring changes asscoiated with the jmod, courtesy Blue95

The third/last post is a write-up on performing the upgrades, specifically on -1997 model 4R70W transmissions, but can be used as a guideline for most years. Courtesy Redmobile.


This article describes upgrading a 1998+ 4R70W using tips from 4R70w guru Jerry. It is meant to be used as a supplement to the J-MOD articles found here:

For -97 AODE/4R70W owners, perform the J-MOD transmission upgrades as outlined in the link above.

Note, For 2005+ panthers the 4R70E (4R75E for 06+) is used. At this time I am unsure if these steps still apply.

Please refer to this BOK article for more accumulator spring info:
J-Mod Accumulator Spring review - by Blue95

The following article was authored by member HookedOnCV, with notes from member Marauderer

Ford 4R70W Transmission upgrade (J-Mod) for late model (1998
and newer) Crown Vic/Grand Marquis/Marauder

Installation notes by Bill Bowker (Marauderer) Presentation by Todd Stafne (HookedOnCV)
© 2004 CrownVic.Net

The following notes were compiled from forum posts by Bill Bowker while he was in the
process of modifying his 2003 Mercury Marauder’s transmission. The J-Mod has been
performed by many people on the 4R70W transmission using the detailed articles found on, however no updates to the article have been published specifically for the late
model Panther platform cars. Over the past several years, Ford has made many of the
improvements called for in the TCCoA article and this presentation summarizes the suggested
changes for our current application.
Please refer to the detailed article posted on TCCoA’s website to gain a full understanding of
what it is you are trying to accomplish with the J-Mod. You will get much more information
pertaining to the overall modification than what is presented here. Use this document only as
a supplement to TCCoA’s transmission article.
I met with Jerry W. this Saturday in Detroit and asked him about his J-Mod for our cars. He
sent me this picture and these updated instructions for late model cars.

"Ignore what the article says and do this...
> Remove the bottom 1-2 accumulator spring and remove the bottom 2-3
> accumulator spring.
> For holes 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

Figure 1
  • Tools:
    • 3/8 drive inch pound torque wrench
    • 3/8 to 1/4 drive adapter
    • snap ring/retaining ring pliers
    • Deep well 10mm socket (1/4” drive)
    • Standard depth 8mm socket (1/4” drive)
    • Pliers
    • Cordless drill with clutch
    • Drill Press (or drill) and drill bits (separator plate mod)
    • Oil drain pan
    • Exacto knife or razor blade
    • (2) Separator Plate Gaskets
      • 1W7Z-7D100-AB
      • 1L3Z-7C155-AA
        -Note: about 2.00 each
    • transmission fluid filter (Motorcraft FT105)-d
    • approximately 8 quarts of transmission fluid (Mercon V!)-d
    • Dielectric Grease
    • Vaseline
    • Carb or brake cleaner
    • Sanding stone or knife sharpening stone
    • Jack, Stands, Lights
  • Step I:
    1. Disconnect the transmission cooler return line where it changes from a hose to a steel line.
      There are two lines coming out of the cooler, you want the upper one. Follow it down; it
      should still be the upper line at the point of change.
      Note: Look under the passenger side, it is in between the frame and the lower crank pulley. A
      quick squeeze of the pliers to move the clamp and you’re done.
    2. Have someone hold it steady and point it into an oil pan. Start the car and let it idle while
      the transmission fluid is pumped out in a continuous stream. Shut the car off as soon as the
      stream starts to sputter or the flow decreases significantly.
    3. Re-attach the transmission cooler line.
      Note: This would be a great time to drain the torque converter if you like.
  • Step II:
    • Jack up the front of the car and place it on jack stands for safety.
  • Step III:
    1. Remove the transmission pan by loosening the 14, 10mm pan bolts.
      • You’re best bet is to use a cordless drill with a 1/4 “ socket drive adapter and a deep well
        10mm ¼” drive socket (you use a ¼” drive because anything larger will not fit between the
        frame and the rear of the pan.
    2. Drop the pan
      • There will be very little fluid left in the pan. You can let it down carefully without fear of
        spillage. The messy part comes later.
      • 4 - 5 items should fall into the pan; a little yellow plastic plunger (discard, it was a temporary plug from the factory), the 2-3 accumulator spring (set aside it does not go back
        in), a metal base for the spring (save), possibly the 2 – 3 shift accumulator itself (a larger
        plunger with a smaller diameter top and larger diameter bottom, and oval shaped filter.
      • Remove the filter; remember to pull out the rubber grommet as it usually sticks.
  • Step IV:
    1. Remove the valve body
      • Prep: layout a canvas under your car, layout a couple of paper towels under the car to set
        the valve body on later, layout a couple of paper towels on your workbench to receive the valve body once it is removed.
    2. Start by removing the black plastic harness from the valve body. It snaps into place in 3-4 locations and is removed with a slight tug at each connection point.
    3. Towards the upper right, remove the bolt with the rooster comb spring (has a roller attached to it ), makes sure to keep the bolt in the hole of the spring as to not lose the orientation of
      either piece.
    4. Adjacent to this is another bolt with a metal bracket, remove this in a like manner.
    5. Now take a look at the valve body and notice that there are two types of bolts; those with
      8mm heads and those with 10mm heads. Do not concern yourself with the 10mm bolts. Look
      closely at the 8mm heads and you will notice that the ones in the middle section (plate
      section) will be a bit longer than those on the periphery. When putting them back, the longer
      ones go in the plated section and the shorter ones go around the periphery.
    6. Remove the periphery bolts (using a cordless drill, an a 8mm socket)
    7. Note the position of the manual valve. It is the piston looking thing and has a notch in it in
      which a pin on the detent lever resides.
    8. Remove the bolts in the plated section, all but one in the center most section.
      • Now get your drain pan ready as here comes the tranny fluid shower
    9. Slowly back out the last bolt about a quarter of an inch and wiggle the valve body slightly so
      that tranny fluid starts flowing.
      • Let this drain for 15 – 20 minutes (should be about 3-4 quarts).
    10. Once the fluid has drained, or you get tired of waiting, hold up the valve body and unscrew
      that last bolt. Hold it firmly and be prepared as it is heavy than it looks and if your car is not
      jacked up high enough you will have little leverage.
    11. Place the valve body on your workbench, gasket side up.
  • Step V:
    Disassembly and Modification.
    1. Use an exacto knife or razorblade to lift a corner of the gasket and remove carefully.
    2. Note the orientation of the two reinforcement plates (circles with 4 bolts each)
    3. Remove the 4 bolts from each plate with a 10mm socket and place on a paper towel in the same pattern as they were prior to removal.
    4. Remove the one 10mm bolt that holds the separator plate in place.
    5. Remove the two plates and place them in the same orientation they were prior to removal (clean with carb or brake cleaner).
    6. Remove the separator plate and clean with carb or brake cleaner.
    7. Drill the holes as prescribed in Jerry’s document (Figure 1)
      • I drilled mine to the following specs:
      • Holes #2, #4, #5, #9, #11 – 7/64 drill bit
      • Hole #10 – 3/32 drill bit
    8. Deburr your drillings with a sanding stone
    9. Remove the remaining gaskets off the valve body
    10. Place the new gasket on the valve body
    11. Clean the separator plate and reinstall
    12. Install the new top gasket
    13. Reinstall the circular reinforcement plates (torque to 90 inch pounds)
    14. Clean the entire valve body paying attention to any electrical connectors
    15. Apply a small amount of dielectric grease to the electrical connectors.
  • It is now ready for re-installation.
  • Step VI:
    1. Under the car; clean the transmission internals with carb or brake cleaner, paying attention to any electrical connectors.
    2. Using the snap ring/retaining ring pliers remove the snap ring from the 1-2 shift accumulator (the round hole on the drivers side front corner [towards the front of the car])
      • Watch out as this ring holds a cover with a spring behind it that is under tension.
    3. Remove the spring.
    4. Replace the cover and the snap ring.
    5. Apply dielectric grease to any electrical connectors.
    6. Clean the oval filter screen that came out during disassembly and apply a small amount of Vaseline on the black plastic (top) and place it back up in the tranny. There is only one place
      for it to go towards the rear right corner. If you look up you will see a space the shape of the black plastic top (a rectangular shape).
    7. The 2-3 shift accumulator may have fallen during the valve body removal. Place it and the spring plate back into the 2-3 shift accumulator hole. The accumulator goes in small end top,
      large end bottom. Press it into the hole slightly. Then install the old round spring base; one side is relatively flat and the other has a point; the point goes down. You may have to bend
      the tabs out on this piece ever so slightly to get it to stay up in the hole.
  • Step VII:
    1. Now reinstall the valve body.
      • Pay close attention to the manual valve (piston looking thing) remember the pin on the detent arm must go just behind the head of the piston.
    2. Hold the valve body up and place one of the long bolts as close to the center as possible.
    3. Reinstall the rooster comb spring and metal bracket in their respective locations.
    4. You can now start the remaining bolts by hand; just a few turns to make sure they are
      seated properly and not cross threaded.
    5. Set your cordless drill to the lowest clutch setting (lightest) and set all bolts; using the included bolt pattern diagram at the end of this document (Figure 2)
    6. Now torque all bolts to 90 inch pounds using the included bolt pattern document (Figure 2).
    7. Reinstall the black plastic electrical connector, snap it firmly into place and make sure that
      each contact point is seated and secure.
    8. Install a new tranny filter (coat the seal with a little tranny fluid).
  • Step VIII:
    1. Reattach the transmission fluid pan (using the original multi-use gasket unless it is damaged).
    2. You can now start the remaining bolts by hand; just a few turns to make sure they are seated properly and not cross threaded.
    3. Set your cordless drill to the lowest clutch setting (lightest) and set all bolts (10mm).
    4. Now torque all bolts to 120 inch pounds.
  • Step IX:
    • Measure the amount of fluid drained from the system (should be about 8 quarts).
    • Fill the transmission through the dip stick tube by the measured amount.
    • Confirm your results!
    • Hold the brake, start your engine, move the shifter through the gear selections, and allow your car to warm up while checking for anything out of the ordinary.
    • Check for leaks.
    • Follow precautionary measures and confirm your good work!


NOTE: The author does not assume any responsibility for personal injury, damaged and/or broken materials during the installation of the aforementioned parts. This document is solely designed as a supplement to a Ford Motor Company shop manual. Please use all necessary and prudent safety precautions before and while performing work on your vehicle.

-----Article submission courtesy HookedOnCV

Edited by dRock96Marquis
Edit Reason: Converted to UBB and added notes

Edited by dRock96Marquis (07/25/10 02:33 AM)
-Panther info & FAQs-

Former owner of a Grand Marquis with a few mods, Grand Marquis "LSE S/C"

#1172159 - 04/19/07 12:04 AM J-Mod accumulator spring review - by Blue95
dRock96Marquis Offline

Posting Addict

Registered: 02/22/05
Posts: 24394
Loc: Maryland
This information is to be used as a supplement to the J-MOD article found in this forum (J-Mod article - by HookedOnCV)
It has lots of information and review/opinions on accumulator springs used for the J-Mod transmission upgrades.

The following was authored by member Blue95, originally posted in this thread

I wanted to follow up on this post about accumulator springs:

I did the j-mod to my 02 CV this weekend and all seems to be good. I never could find anything that gave me actual spring rate comparisons between all the 1-2 and 2-3 accumulator springs, so I sort of winged it based on observation.

I had another valve body and separator plate that I had bought a while back - I had already modified the separator plate as per the tech article on this site: so I just set the original unmodified separator plate in the tranny aside as a spare.

I removed the lower 2-3 accumulator spring (brown), but I decided to keep the lower 1-2 accumulator spring. The 1-2 upper spring was green and I left that one in place. The 1-2 accumulator did not have dual lower springs as I had thought - it had a single yellow spring. I changed it out for a purple spring after setting up a very primitive spring tension rating tool to see if I could compare the spring rates. The purple seemed to have less tension than the yellow. This is what I wanted rather than leaving the spring out altogether. I also replaced all VB gaskets and installed a new 1-2 accumulator piston and cover since I had an extra from the 95 CVPI tranny rebuild. VB was torqued in sequence and to spec and fresh Merc V fluid completed the job.

I bought the car with about 58K miles on it and had immediately changed all fluids, filters, etc, including the tranny. The tranny had not been serviced by anyone else as far as I could tell and the dipstick plug from the factory was still rattling around in the pan.
However I did not drain the TC so a fair amount of old fluid remained. That's OK since I knew I would be back into the tranny fairly soon. Doing this work at about 62K miles added another 8 qts of new fluid to the mix. I will do another service in about 25K miles, I like to do them at 25K-30K intervals.

Driving has shown a nice improvement in the speed and firmness of the shifts. Firmness seems to be dependent on throttle - moderate throttle causes good firm shifts, 3/4 to WOT throttle increases the firmness considerably, snaps thru the gears really nicely. In all cases, I can tell that there is indeed less overlap (slip) between changes, good quick shifts no matter what the speed is.
Overdrive band application is about the same, since I don't think that any mods were made to that circuit. The car does have the larger 2.7" OD servo - I did not remove it because I did not have any other springs to replace the one on the OD servo, so no sense to remove it. Overall I am happy with the results.

Next step will be for the MM airbox/MAF and SCT tune, but I wanted to have the j-mod done on the tranny before doing the tune.

I think that sometimes shift speed and firmness get mixed up in describing shift characteristics. Higher pressure is not always the best, so I'm not a fan of shift kits that just boost line pressure.

I think that the j-mods for both early and late model 4R70W's are very well thought out in their design (by one of the original tranny engineers actually). The hole sizing increase in the separator plate serve to allow greater fluid fill and exhaust so pistons are actuated faster with reduced overlap. Changing (removing) the accumulator springs also impacts the shift firmness. It's just a good way of making better shifts.
-----Information provided by Blue95
-Panther info & FAQs-

Former owner of a Grand Marquis with a few mods, Grand Marquis "LSE S/C"

#4013702 - 05/11/19 08:10 PM Re: J-Mod accumulator spring review - by Blue95 [Re: dRock96Marquis]
BigNSlow Offline

Registered: 01/31/03
Posts: 41278
Here is the JMod write up for the Aero guys to go along with the already existing articles by HookedonCV as well as the TCCOA

Images and mod is done on 96' CV. It should apply to all 92+ AODE/4R70W models. Some of the steps are taken directly from TCCOA.

Tools needed to perform the modifications:

- New separator plate gaskets (2 required) - 1L3Z-7C155-AA, 1W7Z-7D100-AB
- new transmission filter
- updated 1-2 shift piston (optional) - F7AZ-7F251-AA
- different springs (check for required part numbers/colors)
- 12 qts of Mercon V - CXT-5-LM12

Materials needed to perform the modifications:

- Inch-pound torque wrench
- 8mm, 10mm and 13mm sockets and 1/4 ratchet with extensions
- needle nosed pliers
- bottle jack
- Razor blade
- Brake or carb cleaner
- Drill or drill press
- Safety glasses
- Assorted drill bits (check for sizes required)
- File
- rags or towels


Drain the transmission fluid. Refer to this article for info, You can either disconnect the hoses at the cooler and let the engine pump the old fluid out or loosen 14, 10mm transmission pan bolts and let the fluid drain. When it's drained, remove the pan. You will see a transmission filter inserted into the valve body. You can remove it by pulling straight down. Make sure that the orange rubberized ring comes out as well. If it didn't come out you need to pull it out of the valve body. Discard old filter and the ring. The valve body should now be visible.

This step isn't really part of JMod but I will mention it anyway. Aero torque converters come with a drain plug. To drain the converter remove the rubber access plug at the bottom of the tranny. You will see the torque converter. Rotate the engine until the drain plug is visible. Undo the plug and let the fluid drain.

To remove the valve body, first take off all the electrical connectors and set the harness aside. Aeros have a harness with several connectors. Whales just have a single plastic circuit board that's clipped into place.

Undo 25, 8mm bolts. There are 2 different length bolts used. I marked the location of all the longer bolts in the image below.

Note the position of the manual valve solenoid. You will need to reinstall it the same way.

Valve body removed.

Location of the pistons.

Now take the valve body over to your work bench and place it into a pan or something similar because there will be tranny fluid. Unless you want your bench covered in it I suggest using suitable container.

There are 2 separator plate gaskets. Image above shows the top gasket. You should be able to peel it off. If it doesn't come off, use a razor blade to assist in removal. Once removed, discard the old gasket.

Note the orientation of the 3 reinforcing plates. They will need to go back in the same order. Remove 11, 10mm bolts. Note the single bolt in the bottom right corner.

Remove the separator plate. You will see second gasket on the bottom. Peel it off and discard. Scrape the remains with a razor blade.

Careful not to flip the valve body as the check balls will fall out.

Locations of check balls and filter screen are highlighted in green. If you need to clean out your valve body, make sure that all the parts go back to the same locations.

We can now modify the separator plate. You will probably want to clean it first with some brake cleaner. Do not drill the valve body!!! Mark the locations of all the holes to be opened up. Then drill out the holes according to the specs listed below. Some holes may already be opened up to the right spec depending on your model year and setup. Refer to pages 13 and 14 on TCCOA tranny article for more info.

Holes 1, 2 and 3 control 1-2 / 2-1 shift.
Holes 4, 5, 6 control 2-3 / 3-2 shift.
Hole 7 controls manual 2-1 shift.
Holes 8, 9 and 11 control 3-4 / 4-3 shifts.
Hole 10 controls reverse.

Hole 1 (1995 and prior models):

Mild <300 hp - 0.160" - #20
Mild <300 hp with gear change - 0.160" - #20
300-450 hp - 0.160" - #20
450-625 hp - 0.160" - #20

Hole 2 (the larger the hole, the firmer your 1-2 shift will be):

Mild <300 hp - 0.081" - #46
Mild <300 hp with gear change - 0.0995" - #39
300-450 hp - 0.0995" - #39
450-625 hp - 0.125" - 1/8"

Hole 3 (controls 2-1 downshift):

Mild <300 hp - 0.180" - #15
Mild <300 hp with gear change - 0.180" - #15
300-450 hp - 0.180" - #15
450-625 hp - 0.180" - #15

Hole 4:

Mild <300 hp - 0.081" - #46
Mild <300 hp with gear change - 0.0995" - #39
300-450 hp - 0.0995" - #39
450-625 hp - 0.125" - 1/8"

Hole 5:

Mild <300 hp - 0.081" - #46 (if you have 1997 or older use this size ONLY)
Mild <300 hp with gear change - 0.0995" - #39
300-450 hp - 0.0995" - #39
450-625 hp - 0.125" - 1/8" (You must also open up the gasket)

Hole 6:

Mild <300 hp - 0.125" - 1/8" / 0.160" - #20
Mild <300 hp with gear change - 0.125" - 1/8" / slot
300-450 hp - 0.125" - 1/8" / slot
450-625 hp - 0.160" - #20 / slot

Hole 7 (open up this hole to reduce 2-1 manual downshift):

Mild <300 hp - 0.125" - 1/8"
Mild <300 hp with gear change - 0.125" - 1/8"
300-450 hp - 0.125" - 1/8"
450-625 hp - 0.125" - 1/8"

Hole 8 (1995 or older only):

Mild <300 hp - 0.238" - B
300-450 hp - 0.238" - B
450-625 hp - 0.238" - B

Hole 9 (4-3 downshift firmness. 1996 and newer, open up the hole, 1995 and older will have to create a new hole.):

Mild <300 hp - 0.081" - #46
300-450 hp - 0.089" - #43
450-625 hp - 0.0995" - #39

Hole 10 (for faster reverse engagement, open up this hole. The bigger the hole, the faster the engagement):

Mild <300 hp - 0.076" - #48
300-450 hp - 0.089" - #43
450-625 hp - 0.0995" - #39

Hole 11:

Mild <300 hp - 0.081" - #46
300-450 hp - 0.089" - #43
450-625 hp - 0.0995" - #39

When you opened up all the desired holes, make sure to de-burr them with a file. You are now ready to reassemble the valve body.

Install the new lower separator plate gasket. Place the separator plate on top. Reinstall 3 reinforcement plates (Pac Man). Be sure to align them correctly. Torque the bolts to 90 in-lb (7.5 ft-lb). Don't forget the loaner bolt in the corner.

Place the second separator plate gasket on top. The valve body is finished, you can set it aside.

Most people do the shift spring mod as well by either changing to different rate springs or removing the springs entirely. I like my grandpa shifts so I decided to leave my springs alone. I did however replace the 1-2 piston with the updated version. If you have an Aero I suggest replacing both 1-2 and 2-3 aluminum pistons with stamped steel.

Here is a view of the tranny.

A bottle jack works great for removing the pistons. Put a jack under the cap to release pressure. Use needle nose pliers to remove the snap ring. Lower the jack and remove the piston and springs.

1-2 piston removed. You may notice some wear in the case.

#4013704 - 05/11/19 08:11 PM Re: J-Mod accumulator spring review - by Blue95 [Re: dRock96Marquis]
BigNSlow Offline

Registered: 01/31/03
Posts: 41278
Piston comparison. Old aluminum on the left, new stamped steel on the right.

Spring placement inside piston.

This is what the upgraded 2-3 piston looks like. This is from my 2003 Crown Vic. The spring on top of the piston broke in several places.

If you plan on swapping out or removing any springs, refer to this article for more info,

Use the bottle jack to reinstall the pistons back in place.

The valve body can now be reinstalled. Make sure to align the manual valve solenoid correctly.

Use the diagram below for proper tightening sequence. Torque each bolt to 90 in-lb (7.5 ft-lb).

Plug all the electrical connectors back in. Install brand new tranny filter. Reinstall the tranny pan and torque converter drain plug. Refill with fluid as described here,

I ended up using 12 quarts of fluid.

When you first start it up, let it warm up and shift through all the gears. If it doesn't engage right away, chances are you are low on fluid. Take it for a drive. When you get back check the fluid level and add as necessary. I had to drive around the block 4 times before I got the level up to where it should be.


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