Could we get a Jmod explaination and sticky?

[Aren Jay]

I still don't know if 04's need to have this done.

[Zack]

I still don't know if 04's need to have this done.

The only difference between an 03 and 04 is a better one way clutch, a very minor difference in the internal gear ratio and a tad beefier torque converter.

Everything else can be found using the search button.

[JACook]

Both the '03 and '04 use the same one-way intermediate mechanical diode, and the
geartrains are identical. The primary differences between the two are a higher
capacity front pump, revised torque converter, and input shaft speed sensor.

The '04s benefit from the J-Mod exactly the same as the '03s do.

[Marauderjack]

Yep....

J-Mod = Neck Snapping 1-2 and 2-3 shifts!!!:eek: Only time they are relatively smooooth is low RPM's (TC slips and absorbs the shock) or WOT (wheels spin and absorb the shock)!!!:D

If I had it to do over I think I would use Darrin's Kit and separator plate......might be a bit softer according to him??:confused:

Marauderjack:burnout:

[JACook]

From what I've been able to gather, I believe Darrin is using the upper intermediate
accumulator spring for a Mustang 4.6 application. Kind of a not too soft, not too hard,
this one's just right, compromise. ;)

[Marauderjack]

From what I've been able to gather, I believe Darrin is using the upper intermediate
accumulator spring for a Mustang 4.6 application. Kind of a not too soft, not too hard,
this one's just right, compromise. ;)

I put the Mustang springs in and cannot tell much difference at part throttle......still pretty darn harsh!!:cool:

[a_d_a_m]

on my '02 MGM, the shifts are firm at light throttle, but downright abrupt at WOT. just how i want them :D

[Stranger in the Black Sedan]

What is the point of hard shifts if you aren't banging out some serious ET's? I never got why people strive to make shifts really hard with 14, 15+ second cars.

[Eric-Blk2004]

+1 Vic - its like slaming gears in a 4 banger civic chirping tires going no where...

We have crusier cars - you know smooth ride, smooth power...why ruin it with hard shifts.

I understand the 1 2 shift makes or breaks a drag race in terms of times and you want that as firm as possible...but if your that serious why drag a 4500lb car?

[Stranger in the Black Sedan]

Bragging rights. Like my stupid friends in high school. All they did was brag about how they could "chirp second" in their beater cars. I'm not sure who was actually impressed by them.

[BAD MERC]

What is the point of hard shifts if you aren't banging out some serious ET's? I never got why people strive to make shifts really hard with 14, 15+ second cars.


It takes the internal friction out of the tranny. Less friction means less heat and less wear. A wayyyy happier tranny!

[Stranger in the Black Sedan]

It takes the internal friction out of the tranny. Less friction means less heat and less wear. A wayyyy happier tranny!

I don't think there is a problem with transmissions wearing out from "too much friction" on stock or mildly modified 4.6s, SOHC or otherwise.

[sd8683]

If I went to my local tranny shop and asked them if they could do the J-mod procedure would they know what I'm talking about or would they look at me like I had 10 heads, is it a common procedure, or does it just pertain to marauders, mustangs and what not.

Thanks, guys

Sean

[99SVT]

I just did a J-mod to my MarkVIII a couple of weeks ago and it didn't make it too harsh at all, I even left the bottom spring on the 1-2 accumulator out altogether. The only thing is, I didn't drill out the holes to the biggest setting possible. If you're reasonable about the power you're planning to put through the thing then it's easy to make it mild. My Marauder, on the other hand, hasn't had the J-mod done, but has a custom tune done and it shifts way harder than the Mark. The Mark can spin a tire going into 2nd, but it's not that much of a feat with an open diff and hard touring tires. The only time it's harsh is when I lift from WOT just before a gear change, other than that it's just firm and crisp shifting.

This is just my opinion here, but I think that most shops, when they do this to a car they end up setting it up to max; as they have no idea how much power you might try to put into it and want it to survive any abuse you throw at it.

[CKMustangCobra]

I put red clutches and kevlar band and all the crap PLUS the J-mod on the transmission in my old 93 Mark VIII.

It was great for about a week then it got annoying. It would chirp 2nd LOUD at 1/2 throttle. Just driving around town like a normal dude got old quick cause it shifted so hard. It was awesome when the pedal was on the floor though.

I think Marauder (and Mark VIIIs for this matter) should shift nice and smooth... just like someone said before. They are nice, big, comfortable cruisers. A Wolf in sheeps clothing. When the pedal goes down... that's when the trans should react with the situation. Doing the lighter J-mod and using a tuner should be more than enough to accomlish the best of both worlds.

[blackhueys]

when I did my old p71 vic I left everything in it all I did was drill the holes worked great unless I floored it then it would shift hard.

[RF Overlord]

If I went to my local tranny shop and asked them if they could do the J-mod procedure would they know what I'm talking about or would they look at me like I had 10 heads,Depends...if they do a lot of Mustang work, they *should* know what it's about, but most shops probably wouldn't have a clue. They'll just try to sell you a TransGo or B&M shift kit... :shake: