TH400 Competition Components

Most full manual and transbrake valve bodies use what is known as a fixed line pressure system. In a fixed line pressure system, line oil replaces modulator oil at the boost valve and is known as torque signal oil. Because torque signal oil is fed directly to the boost valve in an unregulated state, it results in a fixed line pressure. This fixed line pressure is equal to the maximum pressure value obtainable with a given boost valve diameter and calibrated pressure regulator spring. A fixed line pressure results in maximum pressure related torque capacity at all throttle angles for maximum performance and durability. Torque signal oil pressure usually originates at the case or valve body and must flow to the oil pump and boost valve to be effective. Due to the internal circuit leakage encountered along the way as well oil pressure fluctuations encountered during gear changes, this method is a primitive means of sustaining a steady fixed line pressure. By removing and replacing the  OEM boost valve and pressure regulator spring from the system and installing a calibrated high rate pressure regulator spring and bore plug, the internal circuit leaks and pressure fluctuations which occur in the torque signal circuit no longer have a negative effect on line pressure values. This introduces an incredibly stable fixed line pressure value to the operating system. 

THIS SPECIALIZED COMPONENT WILL RETROFIT AND IMPROVE ALL TH400 TRANSMISSIONS WITH ANY MAKE AND MODEL  TRANSBRAKE OR FULL MANUAL VALVEBODY. FURNISHES A STEADY 200PSI OF LINE PRESSURE.

This extreme duty bushing with Teflon coating reduces wear between the bushing and torque converter drive hub, reduces engine off converter drainback and improves torque converter stability/alignment. Tighter tolerances improve bushing to bore fitment, reducing bushing spin-out.

This kit puts an end to output shaft to case thrust and selective washer failure common to the TH400 in all heavy-duty and hi-performance applications.The kit replaces these items with a high capacity thrust bearing assembly and selective shims to manage thrust loading and allow proper rear end play adjustment. Includes new case bushing.

This kit puts an end to output shaft to case thrust and selective washer failure common to the TH400 in all heavy-duty and hi-performance applications.The kit replaces these items with a high capacity thrust bearing assembly and selective shims to manage thrust loading and allow proper rear end play adjustment. Includes new extreme duty Teflon coated case bushing.

Heavy duty OEM cast aluminum 5 friction direct clutch piston. This piston features casting # 8670208 and is @ .690" thick. This piston does not include a checkball. Fits all OEM five friction direct clutch housings with a checkball.

Heavy duty OEM cast aluminum 5 friction forward clutch piston. This piston features casting # 8623709 and is @ .745" thick.This piston does not include a checkball. Fits all OEM forward clutch housings.

Heavy duty OEM cast aluminum intermediate clutch piston.

Extreme duty OEM double lip front seal with steel shielded garter spring. Superior in function and design to anything currently available for this critical assembly point. Stock is limited.

Premium bare direct housing without checkball. Accepts six .080" clutch plates, six .077" steel plates, .580" piston w/ checkball and 34 element sprag. Great for most performance applications behind engines producing up to 1000 hp and 750 lbs. ft. in vehicles weighing up to 3800 lbs.