Ok, the old post was getting pretty long. So like I promised, here is a group of photos to help others who want to tackle this project.

First, I'll show the re-pin since lots of guys end up doing this, and without pics or diagrams it can be very confusing. The main thing to remember is on the later model trannys the harness on the rear passenger side uses 2 fewer wires, as it splits the power into 3 inside the tranny rather then using 3 supply wires. All you have to do is rearrange the pins to their new order, and park the extra 2 in ports that aren't used. Here's how it looks:

RE-PINNING

Unplug the harness. If you unplug the whole thing it will be much easier, just unplug all 4 connectors, and unplug the main plug and disconnect it from the rear support member.

Remover the black spacer insert:



With a small screwdriver, remove the plastic cover by popping both tabs and pulling it back about 5 inches, you will need the extra length to rearrange them.



Now, with a jeweler sized standard and phillips screwdriver, pry the tiny clip inside the connector back, and push the round end down with the small phillips, it will push back, then you can just pull it out the back


Then pull the insulator blockoff as you will need to move the wires around in it as well.


Now you need to move the pins around into the correct holes. The 2 spare power wires will go in the row of 2 (9 and 10)


Move the pins to their correct holes, and push through the insulater. Seal the unsued hole with silicone to keep water out. You will hear a snap when the wires are seated properly.


My thanks to this article for explaining it all:
http://www.p71interceptor.com/tranny/diagrams/electrical/external/bulkhead/index.html

here are the old and new pin positions:




Once everything is set, push the pins through the insulator and into their new holes, they will click when they are seated.
That's the re-pin, easy!!
*************************************************************

Now for the swap.

Here is the old style, wires and all


and the new solid state style
(turned 90 degrees right from the old style pic)

You can't stop there, you need to replace that solenoid! Then why stop there, do the jmod and make it even better!

In the interest of keeping it brief, this isn't a how-to guide for everyone, but a visual aid for guys who wonder if they can do this. Search the forums well and you will learn all you need to decide if you think you can do this. I just wanted to help people see what is involved. Search carefully for your year and HP as the details vary.

I used a transmission from a 99 Mustang GT. The torque conver does fit but I upgraded to a 04 Marauder TC just to be safe. It does not have a drain plug tho

The newer style transmissions have many internal upgrades. You can see there are many more bolts on the vale body plate to prevent leakage, and it is thicker then the older ones. They also have a diode one way switch rather than the roller style and are unlikely to fail no matter what you do to it. I don't THINK you need to remove the bolts with no collar, though I did. I amy be wrong, I'm sure someone will chme in. They hold the stiffening plate to the bottom of the valve body.

Carefully unclip the circuit board at the left, center right, and upper right. It snaps on. A flat screwdriver will help pry the last one up. There are 3 solenoids. If you go to a newer tranny you need to KEEP the one on the right (the other 2 have the cover). If you do not swap it, you will destroy your PCM as the voltage is different. You will need to TRIM the older style solenoid to fit into the newer style socket. Just set it next to the other one and you can see where to trim it. I also bevelled one side edge to get it to snap into place.


IF you use a newer style tranny, there is a filter the Marks don't have, you can see in the upper left corner below the piston. It will fall out if you remove the valve body while it is in the car. (mine came out on the bench)


When you remove the valve body bolts, it will push out a bit. On the one side, remove the gasket and any traces. DO NOT remove/lose any of the check balls or the tiny filter!

On the "top" side of the valve body, you also remove this gasket, and the 3 pacmen thingies. NOTE where the notches go.


When you have separated the gasket plate, locate the holes you need to drill out and the size bit(s) you need. For 99+ with stock HP a 7/64 will work (.1094) The guide says you should drill .10 to .11 so this is near the max.
Use a drill press if at all possible, smooth any burrs perfectly flat.



More tips:
You don't need to remove the drive shaft, take out (and replace) the front u-joint.

While you're there... IAC super easy to get to (Gen 1 is a bear to get to otherwise) O2 sensors when you drop the exhaust, DPFE sensor, which is a common failure, and inexpensive (the EGR hoses connect to it), and MPLS if it is not new or the newer style with the red or orange gasket that keeps water out. Check your driver cat for integrity (nice honeycomb, not melted)

You don't HAVE to, but I removed the hood, wiper assembly and throttle body for easier access. Then you can also clean out the cabin air intake screen, and any other debris back there
When you reassemble, make sure to get the shifter lined up with the notch. It's a common mistake to forget this. It goes in the FIRST notch.



When you remove the tail stud, index it. The missing tooth gap should align with the paint mark. If CHECK yours immediately as you pull it out as yours may not be marked. Mine was marked and 180 degrees off.


CAREFULLY check your EGR tube. They frequently rust at the flex part. The updated style does not have this. It is nearly impossible to get to this otherwise so maybe just do it if it is in your budget. I paid $120. The warehouse had 3.


If your tranny failed (even if not, really) FLUSH THE COOLER! I got this junk! Oreilly's sells a can that connects to the line and is pressurised. Then blow it out with compressed air to be sure.


If you want to lose a pound off the car, get rid of the ballast just above the tranny rear frame bolts. Mine was rusted and all these steel ball bearings came out... WTF? I discarded it.


I'm sure there are many more tips guys can add (it's late and I've been typing for over an hour) I hope this is helpful. Thanks to everyone who helped me! Esp Blackice! This took me 3 weekends, largley because of one seized tranny bolt, and a delay in getting the TC. I did it with jacks/stands. A lift/tranny jack would make the job immensely easier but you play the cards you get.

checklist:
LOTS of sockets, including an impact socket as the tranny bolts often break any other kind.
lots of rags
rust solvent
front u-joint and a LARGE c clamp
at least 12 quarts Mercon V
a new filter
tranny flush
tranny pan drain plug
heavy duty drill bits if you think you exhaust studs will break (my drivers did, no threads left anyway)
nuts/bolts to repair that
anti-seize lube
TALL jack stands/jacks
lights
digicam so you remember what went where
feel free to add!!

ASE certified
94 Mark VIII pearl/black

Very nice write up and pics.

Thanks for posting.

MOD aka "another Craig"
Mark of Distinction
1993 Light Mocha

AWESOME write up. I'd like to keep this handy myself for future users so I can link to it.

I know you're tired, but one thing I did when I wrote my HOW TO's was I used cardomain's site because it allowed the images to be enlarged...although yours are well-lighted and easy to see.

so...the other question...

How's the ride?
Happy with the JMOD you chose?
I know the peace of mind must be incredible.

congrats...and again, thanks for taking the time to author this post.

94 sprung/97 on air
President/Founder Club 16

thank again Craig

I actually resized all the pics using MS paint, to keep them from being too big. I linked to the main page pics on flickr. I don't think they were that small in original size. Dang, I bet I can't edit that section now tho. Or am I wrong? I was going to update this tonight when I got home anyway. I LOVE it. I took it careful for a while to make sure all the air got out. When I got back on city streets near work, it will chirp 1-2 at about 3/4 throttle. It feels like someone hitting the car if I go WOT, wow! Driving normal you can't even tell, the shifts are so fast and smooth. I'll be enjoying it long after my back stops being sore from the work

My milage also went back up to 29-30. I think the old one had been slipping for a few weeks. The only thing I have to address is a small exhaust leak on the side that kept it's rusty studs, I need to snug it up a bit, but the growl sounded kind of neat too

If anyone does want to see larger pics you can always email me directly.

ASE certified
94 Mark VIII pearl/black

Very nice write up and photos!

That "ballast" with the BB's inside is actually a mass damper to dampen vibrations that get transmitted through the trans mount.

The BB's fell out of my red Mark's damper when I did the trans swap on it too.

One of these days I'll replace it.

One of these days.

Bill, Charter Member of Club 16
1998 White Collector's Edition 109K
1994 Red Garnet Glaze 200k miles
1994 Deep Jewel Green 183k miles

the re-pin photos, as you KNOW are priceless. Many of them on the net throughout the years, have long disappeared. It's great to see them online again.

Keep in mind, you are a supporting member...you have access to 10mb of webspace for photos if needed. Just send an email to Cal, and get the webspace set up...

if you want them larger.
I think they're fine pal...if anyone cant figure out from your photos what they're dealing with, they're already in over their head as it is.

again...awesome job.

The best part about the JMOD is, during mild driving, the shifts are glass...quick, but not whiplash-enducing...but romp on that sucker, and BARK!

also, keep in mind...you have the best of the best...a few WOT 1-2 manual shifts, and you'll be in for a serious awakening. when you select manual 1st, the PCM commands an increase in line pressure, and SHAZAAM when you shift...even at 4500, it's bone-jarring in the mild setting. I have a chip that removes the command to retard timing at shift point, plus a mild increase in line pressure, so if I manually shift in RACE MODE(4 deg timing advance) with increased line pressure at WOT it actually lights up the tires...it's way too much for the driveline to take on a regular basis...last spring on a wide-open stretch of road that was slightly damp, I set it to RACE, manually selected 1st gear and walked it up to 3500 rpms, then went wide open...when I shifted at 6000 rpms, the tires didnt even chirp...they didnt bark...they just set in to a full spin, and I had to counter steer quickly...she was going to come around on me...at 60 mph! That was the last time I played that game on a damp surface.

Just be carefull doing manual 3-2 downshifts with the ground wet...JMOD's = fast downshifts too!

enjoy it pal... you earned it...every last tire-barking shift.

Peace of mind?...oh yea...that's probably the best part when the fun wears off.

94 sprung/97 on air
President/Founder Club 16

Thanks, I actually did get set up with the webspace last week. I'll keep that in mind next time I do a photo spread project, hopefully not for a while!
I suppose now is the time to ask about manual shifting. All I've ever really needed to do is deal with rush hour traffic and pass people on the rural roads. With my VIIs I had to manually shift down to D, and before this failed I would click the OD button, then after the drop give it the gas. What is the preferred method to call for a shift after the jmod? Usually I have plenty of room but there are a few short passing zones that I never consider with the diesel

ASE certified
94 Mark VIII pearl/black

with a JMOD'd 99 tranny, you can drive it like a stick shift with no clutch pedal!

with the mechanical diode one-way clutch(the weak part of a pre-98 tranny), you can do WOT downshifts all day long. But dont go WOT in OD...ever. If you are cruising at say 65 mph, and wish to pass, dont go WOT to encourage a 4-2 downshift though. Just do what you've been doing...turn OFF the OD button, wait for the 4-3 downshift, then have fun.

I dont usually manually shift my car though...not because I fear damage to the tranny, but because the need rarily arises.

I also drive my car like OD is a true 4th gear. I dont use it unless I am cruising at 65 mph or over. I will turn it off when I slow down for freeway exits/traffic braking...but other than that, I drive a 3 speed, if you know what I mean.

94 sprung/97 on air
President/Founder Club 16

And we know what a picture is worth.

'Horn

Thank you this is what I have been looking for. Now I am almost brave enough to try it. Maybe one day.

don't let the jmod intimidate you at all, it's quite easy!

I did remember if you do a swap, get a new dipstick O-ring as well.

And If anyone wonders how 1 man can get a tranny off the bench, make a ramp of sturdy wood, or in my case a horse trailer divider made a perfect steel ramp. Don't want to rent a tranny jack? I drilled a hole in my jack cup and bolted a large (12 x 12) peice of scrap lumber to it, and added eye bolts to the sides to strap the beast down. Not pretty but saved me the jack fee.

ASE certified
94 Mark VIII pearl/black

> Don't want to rent
>a tranny jack? I drilled a hole in my jack cup and bolted a
>large (12 x 12) peice of scrap lumber to it, and added eye
>bolts to the sides to strap the beast down. Not pretty but
>saved me the jack fee.

heh heh...we have used a spare tire wheel with a large bolt through the jack base to hold massive truck 4-speeds to a large truck floorjack.

Like I always say...whatever works for ya

94 sprung/97 on air
President/Founder Club 16

Hey, I also worked out over lunch, my speedo IS off, there was just a plastic cover on the new tranny, so I used the GREEN gear from the old one. What do I need to get it right? Right now 55 on the speedo = about 47. I knew there was no way everyone was going 80-90 mph on the way into town the last few days

( I used one of those radar signs that tell you your speed, it was perfect before the swap)

ASE certified
94 Mark VIII pearl/black

here's what I did, this is the geared ass'y I kept as the other one only had a plug.


ah nevermind, I found this post, I knew it was somewhere:
hammer489 Tue Jul-24-07 03:33 PM
Member since Oct 23rd 2006
178 posts
#66691, "RE: 4R70W out of a Mustang...will it work in an M8?"
In response to Reply # 4
I used an orange 20 tooth speedo gear instead of the green 17 tooth gear and my speedo is right on. 10 bucks from Ford.

I will need to see if I can track one of these down, I'll post the part # if I get it. The ratio is almost exactly when my speedo appears to be off (about 1.16/1)

ASE certified
94 Mark VIII pearl/black

yea...let me know too. My speedo is STILL off. It shows me slightly better fuel mileage since I am really not going as many miles as my car thinks it is.

I used my stock gear...it was off 8 mph at 60. So I tried one from a stock T-Bird...it was off 7 mph at 60.

since we both put Mustang trannies in our 94's, whatever you use, will work for me.

I'll email Torrie at FPN and see if he can get me one. I mostly use my tach for a speedo anyway


good news is, it's one bolt, and one clip-plug...easy swap.

94 sprung/97 on air
President/Founder Club 16

C8SZ-17271-B

It's neon orange. Speedo is right on.

Wow, impressive How to, and really good directions. Pictures are good.
Makes me want to do a transmission swap and Jmod. I do not know what a jmod is but I now want to do one.

Super Dave

lol thanks Dave, I plan on swapping the orange gear tomorrow, I just go the car rescued from the alternator debacle. This project is totally doable for anyone with a little skill and enough tools.

ASE certified
94 Mark VIII pearl/black

ok, the orange gear worked like a charm spot on. 9$ from the dealer.

ASE certified
94 Mark VIII pearl/black