J-Mod Advice

[03sport007]

Need some advice. My car has 57k on it and although everything looks good I’m not sure of the service history so I’ve decided to do a transmission filter change and fluid flush. My plan is to drop the pan and replace the filter and then use the bucket method to replace the rest of the fluid. My question is this: I currently have an tune and absolutely love the way the transmission shifts (Firmness and shift points) and don’t want to change a thing. But I’m also all about doing things to make my transmission last longer so this is a perfect time to do the j-mod. What do you guys think? Do the J-mod and mess with perfection or leave it alone?

[musclemerc]

1) why attempt the bucket method if your dropping the pan?

2) if your happy why change it?

[ntd]

My suggestion is modify the separator plate as this improves the clutch fill and exhaust circuits, this will not make the shifts harder just faster and better timing. Leave the MM accumulator springs installed or use the mustang 4r70 accumulator springs. You can use the bucket method if you want but once you pull the valve body all the fluid drains out of the torque converter so not really needed but it cant hurt.

[tbone]

Yep, leave the springs in, but mod the plate.

[Mr. Man]

I think one of the questions he's asking and I'm curious too is the J-mod beneficial if you already have a tune and conversely is the J-mod a good alternative to a tune?

[wickedmerc]

I think one of the questions he's asking and I'm curious too is the J-mod beneficial if you already have a tune and conversely is the J-mod a good alternative to a tune?

....or is a tune WITH the J-mod the ultimate trans performance?? :popcorn:

[Mr. Man]

....or is a tune WITH the J-mod the ultimate trans performance?? :popcorn:
Yes...that question too.

[justbob]

Simple. Do the Jmod, then back off the pressure in the tune. Done, back to where you are.

[Vostok]

When the dealer flashed away my Z-tune before on accident I drove a couple hundred miles on J-Mod only and it felt really stupid, tune is a must with it.

[03sport007]

Thanks for the quick replies. Sounds like the plan is to modify the valve body for quicker shifts and to use the Mustang accumulator springs and fine tune the firmness with the tune.
Does the dealership carry Mustang accumulator springs? Where is the best place to get one?
I guess I assumed that the transmission had never been serviced and I thought the bucket method was the only way to change all the fluid.

[ctrlraven]

Simple. Do the Jmod, then back off the pressure in the tune. Done, back to where you are.
Yep. Set the shift pressure % to zero after Jmod is done then go from there. May want to increase it or may want to decrease it some.

[Marauderjack]

I have a new OEM separator plate and gaskets if anyone wants to experiment and possibly go back to stock!!:cool:

PM me if interested!!:beer:

[tbone]

Simple. Do the Jmod, then back off the pressure in the tune. Done, back to where you are.

Well, I backed the pressure off to the max with my Zack tune and it still shifts too hard, imho.

[justbob]

Thats weird Tom, never really heard that before? I triple asked Zackzilla on taking them completely out, and basically he said YEEEESSSS~! Now shut up and take em out! I am sooo glad I did.

[03sport007]

Any idea were I can get mustang springs? I called the dealership today and they said the only way to get the springs was to buy a new valve body? I guess the question is raising the shift fimness via spring change different/better for the transmission then rasing the line pressure in the tune?

[ntd]

They looked up the wrong springs they are located in the trans not the main control if needed i can get the part #'s for you tomorrow at work. The mustang springs are a little firmer than the MM springs. If you like how firm you car shifts now leave the MM springs and play with the tune. You want a little more use the mustang springs and adjust with the tune as needed. You want neck snapping tire chirping shifts all the time remove the springs

[Rockettman]

...You can use the bucket method if you want but once you pull the valve body all the fluid drains out of the torque converter and down your arms into your shirt!

There...fixed it for ya.

[Bradley G]

I had justbob leave my springs out and I have nice crisp quick shifts. I love how it shifts.

They looked up the wrong springs they are located in the trans not the main control if needed i can get the part #'s for you tomorrow at work. The mustang springs are a little firmer than the MM springs. If you like how firm you car shifts now leave the MM springs and play with the tune. You want a little more use the mustang springs and adjust with the tune as needed. You want neck snapping tire chirping shifts all the time remove the springs

[massacre]

I have a new OEM separator plate and gaskets if anyone wants to experiment and possibly go back to stock!!:cool:

PM me if interested!!:beer:


............PM sent