Hello everyone, I just wanted to check in and give an update as to how things are going with the 700R4 and share my experiences. So far it has been working pretty well, it shifts when a 700R4 econobox should and the fourth gear with torque converter lockup is a amazing. I’m running 2,000 RPMs on the freeway at 65 MPH. That’s pretty much exactly what I was looking for. There are little details that I’d like to change and as they come up I’ll make sure to document them for the group.
Some things I’ve learned so far:
Transmission fluid has a notable pressure drop when going from ambient to warmed up temperature. Cold temp was 80 F and warm temp was 170F, pressures varied by nearly 80 PSI in park. You might be thinking that is not a big deal but this is the same pressure that keeps the clutches engaged. Long story short, make sure to check and adjust pressures while at operating temperature.
The TCI constant pressure valve body kit applies pressure constantly but not at a constant pressure. You’re thinking, what? … So, it holds a baseline pressure, but of course increases the pressure as you apply additional throttle.
It is highly recommended to get an ADJUSTABLE torque converter lockup vacuum switch; otherwise you could drop out of lockup way early or way late… Trust me; you will want to be able to adjust this to your driving style and preferences.
I have been taking temperature readings over several testing sessions and have consistently recorded the results below for the listed transmission coolers below. Please note these were taken at ambient temperatures of 70 Deg and at 35 mph or lower speeds while driving around town. With colder temperatures and higher speeds the heat dissipation would be greater, but hey you can’t control the weather.
Derale DER-13267
26” aluminum extruded dual pass fin cooler:
5-10 Degrees temperature decrease
Derale DER-15800
Oil Cooler with fan, 11.5 in. x 15.75 in. x 5 in
25-30 Degrees temperature decrease
