Valve Body Parts & Shift Kits

TH400 SHIFT KIT® Valve Body Repair Kit

SHIFT KIT® Valve Body Repair KitFits all 400 1965-on Corrects/Prevents/Reduces: Soft, late shifts 3rd clutch burn-up Rough 1-2 Over sensitive passing gear

TH400 Transmission Stick Shift Reprogramming Kit (1965-1992) TransGo

Turbo 400 Transmission Reprogramming Kit™with Manual Shift ControlFits all 400 1965-on Features: Stick Shift, full manual control Full race; competition, off road and pro-street Converts back to automatic from the outside in 5 minutes Also...

TH400 Transmission Reprogramming Kit - TransGo

Features Automatic shift Street or full race Holds 1st and 2nd to any RPM Back-shifts to 2nd and 1st at any RPM Tow&Go™ or competition Also Includes (2) different size 1-2 shift valves Direct clutch high rate return springs Heavy duty...

TH400 Transmission Reprogramming Pro-Race Kit - TransGo

Features Automatic shift Street or full-race Holds 1st and 2nd to any RPM Back-shifts to 2nd and 1st at any RPM Tow&Go™, competition, pro-race, heavy duty, show-off Awesome capacity with adjustable shift timing and feel Also Includes (2)...

TH400 Line Pressure Booster Kit

TH400 Line Pressure Booster KitPart No. 400-LB1 Sonnax hydraulic line pressure booster kits contain stronger pressure regulator springs and large ratio boost valves designed to work together to provide progressive pressure increases as driving...

TH400 Boost Valve Kit (No O-Rings Style) Sonnax

TH400 Boost Valve KitPart No. 34910-05K Factory Style, No O-Rings Vehicles with a THM 400 transmission frequently have poor line rise, soft 1-2 and/or 2-3 shifts,and/or Reverse engagement difficulties. These problems can be caused by the...

TH400 Boost Valve Kit (O-ring Style) Sonnax

TH400, TH425 Boost Valve KitPart No. 34910-01K O-Ring Style Vehicles with a GM 400 and 425 transmissions frequently have poor line rise, soft 1-2 and/or 2-3 shifts and/or Reverse engagement difficulties. These problems can be caused by the...

TH400 Solenoid Case Connector, 2-Prong w/o Variable Pitch (1970-1982) 8629502

This is a high quality aftermarket replacement case connector with 2-prongs and without variable pitch for GM TH400 transmissions.  The case connector is the style with the insulator.

TH400 Solenoid Case Connector, 1-Prong Small OD (1964) 2977975

This is a new aftermarket replacement case connector with 1-prong and the small OD for GM TH400 transmission manufactured in 1964.

TH400 Solenoid Case Connector, 2-Prong w/ Variable Pitch (1965-1967) 2984091

This is a high quality replacement 2-Prong style TH400 case connector with variable pitch manufactured from 1965 to 1967.

TH400 Solenoid Case Connector, 1-Prong Large OD (1968-1998) 24205373

TH400 3L80 Valve Body Detent Kickdown Solenoid (1965-UP)

New aftermarket replacement Kickdown/Passing Gear/Detent Solenoid used in General Motors Turbo 400 TH375 and TH475 transmissions manufactured from 1965 and up.  Also used in all year 3L80 and 3L80HD transmissions. 

GM Turbo 400 Transmission Valve Body Shift Kit w/ Plate by Superior

GM TH400 Transmission Valve Body Shift Kit by Superior Transmission Parts This shift correction package offers the option of regular and heavy duty applications all in the same kit.  This valve body kit supplies metal rings for the 2nd accumulator...

GM Turbo 400 Transmission Valve Body Shift Kit by Superior

GM Turbo 400 Transmission Valve Body Shift Correction Kit by Superior Transmission Parts The Superior 400 valve body kit offers the option of regular and heavy duty applications all in the same kit.  The kit supplies metal rings for the 2nd...

GM 700R4 TH350 TH250 TH400 Governor Shift Point Package by Superior

Superior GM Shift Point Package GM 700R4 / TH400 / TH350 / TH350C / TH250 / TH250C This kit includes 6 weights and 6 springs to offer a wide range of adjustments.  The kit includes new weigh pins with E-clip ends for easy adjustment.  This...

GM TH400 TransAction Shift Kit by Fairbanks (1965-UP) Heavy Duty, Street/Strip, Manual Control & Full Competition

Fairbanks Turbo 400 TransAction Shift Kit 1965-UP GM TH400 Transmissions Offers 4-Levels of Performance Heavy Duty: Use for towing, off-road vehicles, campers, motor homes/RVs, trailers, and any other vehicle that does a lot of stopping and going...

GM TH400 Posi Shift Kit by Fairbanks (1965-UP) Heavy Duty & Street/Strip

High Performance Turbo 400 Posi Shift 2 Stage Kit Heavy Duty & Street/Strip Applications Step Up Your TH400 Without Removing Your Transmission!   Why Use This TH400 Posi Shift Kit Fairbanks's Posi Shift Kits will firm up the 1-2 and 2-3 shifts...