Hi folks.

I'm considering a shift kit for my '99 4R70W, but really like the price of the J-mod (free) if it's just as effective. Has anyone applied this mod to a 99+ 4R70W? What about the "improved components" I've seen listed? Do we newer-tranny folks already have them?

Truck is used for towing a 4,000# travel trailer, as well as occasional daily-driver-type use, and is a 1999 extended-cab 4x4 with the 5.4.

If the J-mod is not applicable or not recommended (why?), what have folks found to be the preferred kit for my usage?

All input will be welcome and appreciated. Thank you!

Andy

 

I did the Jmod on my 2wd 2000 F150 and love it! Just follow his instructions to the letter and you won't be disappointed.
So far I have not seen any shift kit that is as effective, harmless, and cheap as the Jmod.
It is also worth mentioning that I did the Jmod on my truck at 100,000 miles, and the previous owner had never changed the trans fluid. I did it anyway, and it has worked flawlessly ever since.
75,000 abusively driven miles later, I am still shifting hard and fast, and I can still burn rubber on the 2-3 shift. I have changed the fluid in the trans a few times since doing the mod, and I haven't had any excessive amounts of friction material or metal shavings in the magnet, just normal accumulation.

Do it. Do it now. You won't be sorry.

 

Hi.

First - do more research.... then decide.

J-Mods are not recommended:

https://www.f150online.com/forums/sh...highlight=jmod

 

Thanks for the input.

I do recall seeing that the J-mod doesn't work as well for trucks. Maybe it has to do with the loads encoutered or the valving being different for a truck vs. a car?

In any case, I just talked with Gregg at Factory Tech, and it sounds like his modified separator plate should be just the ticket. (Being a '99, I don't need the whole valve body.) Only $85 from him directly, and the truck can easily be returned to stock later if necessary. Plus, I can choose to install the 1-2 and 2-3 accumulators/springs, or not, depending on how firm I want the shifts.

Now I have a decision to make. To do or not to do.....and how much to do if I do do.

Andy

 

I picked up a Superior Shift Improvement kit from Napa for $45 and some new valve body gaskets from Ford for around $10 and it made a huge difference in the way the truck performs now! I love it.