NTBA

Trannys & Torque Converters

T Buckets being what they are, run extremely well on stock automatic transmissions. The tranny you're using most likely came out of a fairly heavy vehicle, and is now in a light weight T Bucket. So the tranny isn't going to have to work too hard. However, there are a few things to consider. Have you noticed your T shifts too soon while in drive? Or, it jumps when you drop it into gear? Do you have a hard time holding your T at a stop light(with it in gear)? These are the kind of things you can expect from a stock transmisssion.

There are somethings you can do to make your tranny T Bucket worthy.

First of all, get rid of that stock torque converter! It pulls too hard when you're stopped in gear. The stall rate is way too low for a T Bucket. Let's think about this for a second... A stock converter will stall(lock up) around 1500RPM in a 4000 pound car. That same converter will attempt to stall around 900/1000RPM in a 1500 pound T Bucket. So you're sitting at a traffic light idling at 750RPM or more, and your T Bucket wants to GO. You press hard on the brakes to force the converter to slip. Or you drop the tranny into neutral while sitting there(that's what I used to do). What a pain in the butt! So I replaced mine with a 2800 stall converter. The acual stall is around 1900RPM in my T. I can live with that! Now I can hold my T at a stop with minimum brakes, and the accelleration is AWESOME. The stall is still a bit low for drag racing applications but great for the street. For drag racing, you want your converter to stall at maximum torque of your engine. So if your engine peaks at say, 3500RPM then the converter stall should be at 3500 including the weight of your vehicle. Any reputable torque converter mfg. can calculate the correct stall for your application. You will have to provide a lot of information about your T Bucket. Weight, horsepower, rearaxle ratio, tire diameter, transmission, etc. etc.etc...

OK, you now have a new converter. It still shifts too soon while in drive. Two things manage this. The governer and vacuum modulator(on most transmissions). These two items struggle against each other. The governer wants to hold back the shift points, and the modulator wants to force a shift, depending on vacuum signal from the engine. So get an adjustable modulator, and "tune" it to your application.

NOW, you have a high stall converter and a tuned modulator. The shifts feel a little bit "soft" under normal driving conditions. This is to be expected with a high stall converter. Remember, the new converter won't be stalled until it reaches a higher RPM. So no matter how hard the tranny shifts, the converter will always slip when below its stall making the low RPM shifts "feel" a bit soft. TRUST ME ON THIS ONE, if you hold your shifts past the stall RPM, you will experience monster ass kicking shifts unlike anything you've ever witnessed! I actually popped a second gear wheelie the first time I held the gears! I was taching about 5500 RPM when I hit second. What a rush!

Transmission Coolers:
Get one, put it in as soon as possible! Do not depend on internal radiator coolers(they're a joke). Heat is your trannys worst nightmare! And high stall converters generate heat.

Shift Kits:
Not recommended. But if you just have to have one, re-install the balls no matter what the instruction say. Most transmissions CAN'T withstand the hydro-shock. Eventually you WILL damage the case, clutch drums and pistons, GUARANTEED. Even if your tranny "seems" to be working properly.

LAST WORD OF CAUTION:
Use whatever fliud your transmission calls for. And stay away from "trick" fluids. Your T Bucket doesn't need it, and your tranny doesn't like it.

Happy Rodding, Bucketheads!

Mark Fuess