xruiz said:
Ok guys here's the deal, I'm debating on wether to get a set of gears or a shift kit for my auto tranny. I need to know what you guys think would be the best thing to get. I do ALOT of driving on the highway at around 80 if that matters at all. Thanks in advance.
Gearbanger101 said:
Before doing anything to your transmission, I have to push the idea of a transmission cooler your way first. I can not stress how important these things are. Heat is the number 1 killer of automatic transmissions. A transmission cooler will reduce heat build up in the transmission. Many companies manufacture transmission coolers. I personally use the one from Steeda. I've had it for about 4 years now, and it works great. My brother uses one from Flex-a-lite in his with no complaints or problems with the cooler. B&M makes some nice ones, and if you have the money, you can dig deep and get one with an electric fan on it to help increase cooling abilities. Either way, be sure to get a transmission cooler.
Next, read these articles to learn how your transmission works.....
http://www.tccoa.com/articles/tranny/transmission/index.shtml
Pay closer attention to the articles on the 4r70w automatic transmission. Though it is a Thunderbird and Cougar club, the articles still pertain to the 4r70w transmission, which is what we use. You can trust this information, as the guy who wrote the articles was a former Ford transmission engineer.
Special Note: The 98+ 4r70w automatics already have the rubber bonded accumulator pistons, and the internal clutch plates are fine for a n/a application under 400rwhp. So, don't worry about upgrading those. The only thing you need to do is modify the valve body seperator plate holes and accumulator spring pistons. Keep that in mind when reading the following articles in the following links.
For the shift kit, you can find more info here on how to install the shift kit....
http://www.tccoa.com/articles/tranny/transmission/shiftybusiness.shtml
To learn how to modify the stock valve body for the Jerrys' specs, read here....
http://www.tccoa.com/articles/tranny/shiftybusiness.html
As for gears, it all depends on what your future plans are. If you're planning on adding a power adder in the future, like a supercharger, then 3.73's would probably be more ideal. If you're staying n/a, then 4.10s or 4.30's is what I recommend. I run 4.30's in my car every day and I have no complaints.
After doing gears to your car, you will need a ECU flash or chip to correct the speedometer and shift points for the new gears. I recommend getting a custom built program or tune from Superchips Tuning. Thats what I have and it works great.
If you have any other questions, feel free to ask.