TorqueFlite 727 Burned Front Clutches

AbodyBB said
I’m recalling a comment from almost 30 yrs ago so I cannot be entirely sure of what exactly was said. But I was told that the forward clutches are third gear. Third gear depends on the kickdown for proper line pressure. Without the spring the kickdown will remain in a position that drops line pressure. The lack of pressure means less force on the clutches and of course slippage.
On reassembly ensure the kickdown is assembled correctly and will travel to the furthest position in WOT and returns the the forward position completely whit the throttle closed. To eliminate any other issue put a pressure gauge on it when you first drive it. 60-90 psi is what you’re looking for.
Be sure the governer is free as that is what has taken out two of my transmission builds in the past.

You're correct that the front clutch controls direct drive and reverse and definitely relies on throttle pressure signal for proper governor function. I haven't checked pressures, but I'm going to buy a pair of gauges and do so with the car in the air once I have the engine/transmission installed. I wish I checked those pressures before pulling the transmission, but it seemed to be shifting fine to where I didn't expect the issue aside from the smell of burned fluid.

I have the line pressure and throttle pressure adjustments set at the factory specs. The 1965 factory manual calls for 54 - 60 psi of line pressure at 1,000 RPM with the transmission in direct drive and shifted into 3rd/direct drive. With full throttle pressure, the psi should be 90 - 96 psi just before or at kickdown. The front servo release pressures should follow the line pressure +- 3 psi.

What has me thinking the issue might be in the reverse circuit is that the front and rear clutches rely on the same line pressure when the transmission is in 3rd/direct drive. If the mechanical line pressure were too low, I would expect both the front and rear clutches to show signs of slipping, but the rear clutch looks fine. However, I wonder if the additional force on the rear clutch provided by the Belleville spring is enough to stop the rear clutch from slipping whereas the front clutch doesn't have that extra force multiplier?

If direct drive line and front servo release pressures check out, which I won't know for a while, I suspect the reverse line pressure might be too low. My manual calls for 240 - 280 psi at 1,600 RPM.