Hard Parts

TH400 4L80E HD Sprag Element | Sonnax

Sonnax heavy duty sprag element 34658-HD is the ideal upgrade for GM TH400, 4L80-E, 4L85-E intermediate sprags in performance racing transmissions. Designed for Pro Mod-style direct drums, the Sonnax...

TH400 Early-4L80E Case Saver Retainer | Sonnax

TH400 (All Years) 4L80E (1991-1998) Case Saver Retainer Sonnax Part Number: 34762-10 Sonnax case saver retainer 34762-10 for the GM TH400 and '98-earlier 4L80-E is the only intermediat

TH400 Stator Support Shaft | Sonnax

TH400 Stator Support Shaft Sonnax Part Number: 34910S-01 Sonnax GM TH400 stator support shaft 34910S-01 is a heavy-duty upgrade with improved material and design features for enh

TH400 Shift Lever Kit | Sonnax

TH400 Shift Lever Kit Sonnax Part Number: 38512-01K Sonnax shift lever kit 38512-01K uses an O-ring on the shaft to prevent leakage from GM TH400 cases. Built with sturdy, solid steel

TH400 Smart-Tech® Drum Module | Sonnax | Racing Applications

TH400 Smart-Tech® Drum Module FOR RACING APPLICATIONS THAT DO NOT USE FRONT BAND AND RUN A 1'' MAIN SHAFT Sonnax Part Number: 34555-01K

TH400 4L80E Planet Pinion Pin | Sonnax | 4-Pack

TH400 4L80E 4L85E Output & Reaction Planet Pinion Pin Sonnax Part Number: 34875-01  

Powerglide TH400 High RPM Checkball Capsule | Sonnax | 5-Pack

TH400 Powerglide High RPM Checkball Capsule Sonnax Part Number: 57510-01 Sonnax high RPM checkball capsule 57510-01 is specially calibrated to prevent pressure drops in high RPM GM TH400 and...

TH400 4L80E 4L85E HD Main Shaft | Sonnax

TH400 4L80E 4L85E Heavy Duty Main Shaft Sonnax Part Number: 34672-01 Main shaft failure is a common problem in performance and heavy duty GM TH400, 4L80-E and 4L85-E units. Sonnax heav

TH400 HD Input Shaft | Sonnax | WITHOUT Turbine Support Bushing in Converter Style

TH400 Extreme Duty Input Shaft  FOR USE WITHOUT INTERNAL TURBINE SUPPORT BUSHING IN CONVERTER Sonnax Part Number: 30280-01

TH400 HD Input Shaft | Sonnax | Turbine Support Bushing in Converter Style

TH400 Extreme Duty Input Shaft  FOR USE WITH TURBINE SUPPORT BUSHING IN CONVERTER Sonnax Part Number: 30280-02 Input shaft failure

TH400 HD Forward Drum | Sonnax

TH400 Heavy Duty Forward Drum Sonnax Part Number: 34554-01 The ideal GM TH400 upgrade for any power level, Sonnax heavy duty forward drum 34554-01 features a unique combination of high-strength,...

Powerglide TH400 4L80E HD Clutch Retaining Ring | Sonnax

TH400 4L80E Heavy Duty Clutch Retaining Ring Sonnax Part Number: 28124 Sonnax heavy duty clutch retaining ring 28124 can be used as an upgrade for the Reverse clutch backing plate retaining ring in...

TH400 4L80E Extreme Duty Main Shaft | Sonnax

TH400 4L80E Extreme Duty Main Shaft Sonnax Part Number: 34672-05 Main shaft failure is a common problem in extreme duty GM TH400, 4L80-E and 4L85-E units. OE and aftermarket shafts simply don’t hold...

TH400 Extreme Duty Input Shaft | Sonnax | Retro Required

TH400 Extreme Duty Input Shaft  USING THIS SHAFT REQUIRES CHANGING TO A 35-SPLINE TURBINE HUB IN THE TORQUE CONVERTER AND USE OF PUMP COVER BIG SHAFT STATOR SUPPORT TUBE KIT 28154S-125 WITH LARGER...

TH400 Extreme Duty Input Shaft | Sonnax | Pumps Converted to 27-Spline 1-3/16'' Shaft Configuration

TH400 Extreme Duty Input Shaft  THIS SHAFT IS INTENDED FOR USE IN UNITS ALREADY SET UP FOR A 27-SPLINE TURBINE HUB IN THE TORQUE CONVERTER ANDA. PUMP AND STATOR ASSEMBLY CONFIGURED FOR A 1-3/16''...

TH400 Clutch Volume Spacer Kit | Sonnax | Use w/ 34554-01 Drum

TH400 Clutch Volume Spacer Kit FOR USE WITH HEAVY DUTY FORWARD DRUM 34554-01 Sonnax Part Number: 34554-11K Sonnax heavy duty forward drum 34554-01

TH400 4L80E MT540 Forward & Direct Clutch Inner Snap Ring | Sonnax | 5-Pack

Allison AT540 AT543 AT545 GM 4L80E Turbo 400 Forward & Direct Clutch Inner Snap Ring Pack-of-5

TH400 Intermediate Sun Gear Shaft | 32-Spline

TH400 Late Design Intermediate Sun Gear Shaft  32-Spline  

TH400 Intermediate Sun Gear Shaft | 28-Spline

TH400 Early Design Intermediate Sun Gear Shaft  28-Spline  

TH400 Smart-Tech® Drum Module for Big Main Shaft | Sonnax

TH400 Smart-Tech® Drum Module for Big Main Shaft FOR RACING APPLICATIONS THAT DO NOT USE FRONT BAND AND RUN A COAN RACING XST 1-1/8'' MAIN SHAFT Sonn