Hard Parts

TH400 4L80E Low Roller Clutch Assembly - HD | Sonnax

Sonnax part number: 34654HD-01K Protect against direct drum and low roller clutch failure in GM TH400, 4L80-E and 4L85-E transmissions with the Sonnax heavy duty roller clutch assembly 34654HD-01K...

TH400 4L80E HD Sprag Element | Sonnax

Sonnax part number: 34658-HD 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...

TH400 Early-4L80E Case Saver Retainer | Sonnax

Sonnax part number: 34762-10 TH400 (All Years) 4L80E (1991-1998) Case Saver Retainer Sonnax case saver retainer 34762-10 for the GM TH400 and '98-earlier 4L80-E is the only intermediate clutch...

TH400 Stator Support Shaft | Sonnax

Sonnax part number: 34910S-01Fits: TH400 Heavy-duty stator support shaft for the GM TH400, made by Sonnax from heat-treated chromoly steel with induction-hardened splines and serrations. Sonnax...

TH400 Shift Lever Kit | Sonnax

Sonnax part number: 38512-01KFits: TH400 Shift lever kit for GM TH400 automatic transmissions, made by Sonnax, part number 38512-01K. The bolt-together lever is solid steel and zinc-plated for...

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

Sonnax part number: 34555-01K FOR RACING APPLICATIONS THAT DO NOT USE FRONT BAN

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

Sonnax part number: 34875-01Fits: TH400, 4L80E A planet pinion pin from Sonnax, used in the output and reaction planetary assemblies of TH400, 4L80E and 4L85E transmissions. A pinion pin is the shaft...

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

Sonnax part number: 57510-01 TH400 Powerglide High RPM Checkball Capsule 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

Sonnax part number: 34672-01Fits: TH400, 4L80-E, 4L85-E Main shaft failure is a common problem in performance and heavy duty GM TH400, 4L80-E and 4L85-E units. Sonnax heavy duty main shaft 34672-01...

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

Sonnax part number: 30280-01 FOR USE WITHOUT INTERNAL TURBINE SUPPORT BUSHING I

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

Sonnax part number: 30280-02 FOR USE WITH TURBINE SUPPORT BUSHING IN CONVERTER<

TH400 HD Forward Drum | Sonnax

Sonnax part number: 34554-01 TH400 Heavy Duty Forward Drum 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

Sonnax part number: 28124 A heavy duty clutch retaining ring for GM Powerglide, TH400, 4L80E and 4L85E automatic transmissions, made by Sonnax. It can be used as an upgrade for the reverse clutch...

TH400 4L80E Extreme Duty Main Shaft | Sonnax

Sonnax part number: 34672-05Fits: TH400, 4L80-E, 4L85-E 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 up in...

TH400 Extreme Duty Input Shaft | Sonnax | Retro Required

Sonnax part number: 35280-02 USING THIS SHAFT REQUIRES CHANGING TO A 35-SPLINE

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

Sonnax part number: 27280-02 THIS SHAFT IS INTENDED FOR USE IN UNITS ALREADY SE

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

Sonnax part number: 34554-11K FOR USE WITH HEAVY DUTY FORWARD DRUM

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

Sonnax part number: 34577-01 A forward and direct clutch inner snap ring for TH400, 4L80E and MT540 automatic transmissions, and for Allison AT540, AT543 and AT545 transmissions, made by Sonnax. It...

TH400 Intermediate Sun Gear Shaft | 32-Spline

Part number: 1238DFits: TH400 Used intermediate sun gear shaft for the TH400, in the late-design 32-spline version. It is a used hard part, not a new one.

TH400 Intermediate Sun Gear Shaft | 28-Spline

Part number: 1238CFits: TH400 A new early-design intermediate sun gear shaft for TH400 automatic transmissions. It carries 28 splines and is sized for the intermediate sun gear position in the...