Ok, so finally an update: I've rebuilt the trans (frictions, seals, gaskets, reman tc, and valve body with updated main pressure piston) and it's back in the car and driving. BUT, I still have the same problem with the LUC slipping at anything above ~4k rpm. It has noticeable loss of power to the drive wheels when accelerating hard and an audible murmur. The only other thing I could think it would be is the lubrication valve. Should I try getting the oversized one from sonnax? They claim it will solve TCC pressure issues. Other than this, the trans is shifting as smooth as butter and feels great! Hoping that RRphil could chime in on this.

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2001 4.4i E53 172k 01/01 Mfg

Mods: Led interior lights, rear footwell lights, black powder coated rims, carbon fiber wrapped interior trim, matte black ecs kidney grilles, arnott air springs(rear), rear console-quad usb chargers, K&N air filter, akebono ceramic brake pads & zimmerman rotors, black painted calipers, 5% rear window tint over factory tint, 50% front window tint, rear airbags activated, 4:3 nav head unit auxilary input, diy trans rebuild at 160k, spyder led tailights, hella horns