If the idea of dual feeding the clutch pack is to add more surface area on the piston to be pressurized doesn't drilling a hole in the chamber that is being pressurized bleed off the pressure?
Rebuilding a 4L80e, you think I will have any issues NOT drilling a bleed hole in the drum? I did dual feed as you described , but have seen others talk about drilling a hole but not explaining why it’s needed if I’m not running a trans brake
Keeps the piston from centrifugally applying the direct clutches when the transmission is in 1st gear and the direct drum is counter rotating 85ish% of input rpm. If you want your direct clutches to have the best chance at survival, drill the hole
It is not needed to do the dual feed. Dual feed just refers to how the fluid is applied to the direct piston. It (the 1/16” bleed) is not needed for a rebuild in an autoshift transmission that’s behind a stockish engine. Definitely required in anything performance or with a trans brake.
