The idea of getting better fuel mileage is appealing to everyone. Technically speaking, another bonus in putting a T-700R4 in the place of a 3 speed automatic transmission particularly the T-400 is that the T-700 has a lower first gear ratio. This will be very noticeable upon acceleration, the lower ratio will make your vehicle more peppy on take off and reduce the stress on the drive-line.
Everything needed to convert your vehicle from a 3 speed automatic transmission to a 4 speed overdrive transmission with a lockup torque converter can be purchased at the dealer (I would purchase my transmission from GotTransmissions.com) or through the after-market. Most of the after-market parts are just fine to use and more cost effective. Either way, when you get done with your swap over, no one would be able to tell that it had a 3 speed ever. Factory baby..
Here is what you need other then stock hardware.
1. Rebuilt, Good Used, New T-700R4
2. T-700 R4 dipstick- $15.00-$25.00
3. Throttle velocity cable (TV)- $ 30.00 – $40.00
4. T.V cable bracket for the carburetor or injector base. $ 30.00 ish
5. Drive-shaft. You may not need to mess with your drive-shaft if your old transmission is the same length as a T-700R4 (all T-700 2 wheel drive tranny’s are the same length). If you need a longer driveshaft, a junkyard probably has one for cheap. If your drive-shaft needs to shortened, it costs roughly $45.00 to 75.00 to shorten it and re-balance it.
Generally speaking if a transmission shop does the swap over these parts are either in stock or very easy to get. If you are of the mechanical type than you know exactly what I’m talking about. Basically it is most probable you would spend about $250.00-$400.00 bucks more to do this procedure (depending on who does it) than go back with the stock 3 speed transmission. Like I said yesterday, it will pay for itself in a year or so in more ways than one.
I even bought the T-700R4 dash indicator at the dealer so shifter indicator reads properly.
At this time, I always recommend adding an auxiliary external transmission cooler to protect your fresh transmission from one of it’s main enemies-heat. Don’t forget to use synthetic automatic transmission fluid (ATF), you will need about 13 total quarts.
Once you complete the job, make sure you check the transmission fluid properly. More information on T-700R4 transmissions and some great upgrades are on the GotTransmissions Blog for your convenience. Tune in tomorrow for a small add on tutorial on the way to convert a four wheel drive to an a T-700R4. Don’t worry, it is just as elementary as a two wheel drive. Good luck and enjoy.