tomustang said:
J-mod, tq converter, gears and a tuner to firm up the shifts will set you straight and 5sp'd too
sgarlic said:
Oh yeah.. before you bother doing any other mods to your tranny, get a nice tranny cooler if you haven't already. It'll lower temperatures and extend yourtransmission life.

This was one of my first modifications. Heat breaks down the Meron in transmission fluid, which is the key ingredient for protection against friction. Once the Mercon is gone, the parts start to recieve excessive wear and tear. This can be avoided with a simple transmission cooler. I use the one from Steeda and I've had no problems with it. Other good companies for coolers are Flex-a-lite, B&M, and Performance Automatic( I think they make a cooler).
tomustang said:
shifts-kits are usually worse for the 4R70W
If not installed correctly, or using the wrong shift kit, such as shift kits that use blocker rings or require you to tamper with the line pressure, via the pressure control solenoid, then you run the risk of seriously damaging the transmission. Blocker rings are to be avoided, as they only shorted the "stroke" of the accumulator piston during shifts. This is bad news, because the accumulator piston should fully stroke when engaging gear shifts. Tampering with line pressure will result in firmer shifts, but at a potential price of starving certain internal clutches of proper lubrication. Avoid tampering with line pressure at all costs.
streetstang03 said:
read the tranny articles here about the Jerry Mod
I agree. Read all the articles involving the Jerry mod shift kit. It will help explains things and give you a better idea of how the 4r70w transmission operates.
A few quick notes. If you're not mechanically minded, or have never worked on a transmission before, you might want to let someone else do this job. Any good transmission shop should be able to handle this for you. It involves simply pulling the stock valve body, enlarging certain holes in the seperator plate, swapping a spring in one accumulator piston, and removing a spring from the other accumulator piston. Its pretty straight forward. Be sure to pick up the new seperator plate gaskets that you will need. These are a must. I did the Jerry mod once on my car, the gasket was bad(though it looked brand new), I put it back in, and the transmission blew on me. Learn from my mistake.