No one knows transmissions & torque converters like


No one knows transmissions & torque converters like 2008-sonnax-logo-white

Torque Converter Robothead
Maybe it’s not the torque converter!

View Transmission Parts for Resolving & Preventing Torque Converter Problems


Increase Your Torque Capacity with Sonnax Multi-Plate Converter Clutch Kits

To upgrade the torque converter, Sonnax offers heavy duty multi-plate converter clutch kits with all the components needed to build a complete piston/damper assembly tuned to your specifications.

  • Utilizes three high thermal, high-torque capacity friction elements
  • Improved oil flow across clutch plates
  • Improved spring end caps prevent over-compression
  • Reduced overall weight
  • Clear step-by-step instructions for easy installation
  • Increased strength cover
See All Sonnax Multi-Plate Converter Clutch Kits

Nobody knows torque converters like Sonnax.

Sonnax is the world's leading supplier of aftermarket torque converter components for domestic, import, industrial, racing and heavy-duty converters. Our extensive selection of parts combines the latest in automotive technology with outstanding reliability, performance and durability for long-lasting, trouble-free rebuilds.


Sonnax Racekits

Sonnax 8" and 10" non-lockup racekits are popular with converter rebuilders supplementing their stock rebuild with performance units for drag, sand rail, rock climbing, swamp buggy and mud racing.

New for 2014 – Fully Machined Front Covers!

Sonnax racekits traditionally featured partially machined front covers, with much of the outer face remaining as forged. In response to many requests from rebuilders to offer fully machined covers, Sonnax is pleased to announce this upgrade is now being implemented for all the 8" and 10" racekits.

Sonnax also will be pressing bushings into place on all covers except that found in the FD-RK-1 so that rebuilders no longer need to spend time on this step.

Stay Ahead of the Pack with Sonnax Racekits

  • Fully machined cover with bushing installed
  • Unit-specific design for hassle-free installation
  • Oil flow grooves and holes increase fluid flow to keep converters running cooler
  • Turbine hub features a larger flanged diameter to increase strength and rigidity of the turbine.
  • Clear, detailed instructions

Keep up-to-date with all new and improved kits by becoming a Sonnax Insider today!

See All Sonnax Racekits

Upgraded Racekits

These racekits are already available with fully machined front covers.

Application Part No.
10" Racekit AOD FD-RK-1
10" Racekit C4 10" & 11" FD-RK-3
10" Racekit C6 FD-RK-4
10" Racekit C4 11" FD-RK-9
10" Racekit 4L60 GM-RK-9
27 Spline
30 Spline
10" Racekit Powerglide®, 350, 400 GM-RK-1
30 Spline
Small Bolt Pattern
17 Spline
8" Racekit 350 & 400 GM-RK-2

New Parts

Friction Ring Friction Ring

  • Thickness: 0.045"
  • Outer Dia.: 9.563"
  • Inner Dia.: 8.500"
  • Material: HTE
Friction Ring Friction Ring

  • Thickness: 0.066"
  • Outer Dia.: 9.563"
  • Inner Dia.: 8.500"
  • Material: HTE
Friction Ring Friction Ring

  • Thickness: 0.066"
  • Inner Dia.: 9.188"
  • Outer Dia.: 10.500"
  • Material: HTE
Friction Ring Friction Ring

  • Thickness: 0.066"
  • Inner Dia.: 9.840"
  • Outer Dia.: 11.120"
  • Material: HTE
Friction Ring Friction Ring

  • Thickness: 0.066"
  • Inner Dia.: 8.125"
  • Outer Dia.: 9.125"
  • Material: HTE
Friction Ring Friction Ring

  • Thickness: 0.045"
  • Inner Dia.: 8.938"
  • Outer Dia.: 9.398"
  • Material: HTE
Piston Seal Piston Seal

Sonnax solid piston seal AL-O-3 replaces worn or damaged seals in 2010–2012 Allison LCT 1000 captive clutch converters.

  • Height: 0.100"
  • Width: 0.091"
  • Outer Dia.: 3.160"
  • Material: PTFE
  • Seal Style: Solid
  • Color: White
Radial Lip Seal Radial Lip Seal

Sonnax radial lip seal FD-O-32V replaces worn or damaged seals in Ford 6R80 converters.

  • Housing Bore: 1.181"
  • Shaft Dia.: 0.871"
  • Material: Fluorocarbon
View more new Torque Converter parts View all Torque Converter parts