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4L80-E, 4L85-E, Multi-Plate Performance Converter

265mm Damperless Multi-Plate Racekit
Part No. GM-RK-485

Street/Strip applications only.

View Instructions

A performance torque converter is highly specialized based on the performance characteristics of the specific vehicle. Sonnax has several levels of kits to ensure the best combination of performance and value for each application.

Sonnax damperless multi-plate racekit GM-RK-485 for GM 4L80-E, 4L85-E applications delivers the performance characteristics of a high-stall with maximum lockup capacity. Sonnax racekits ensure fast, easy assembly with predictable tuning adjustments.

Sonnax offers the most comprehensive range — and growing number — of converter kits for anyone building a GM 4L80-E, 4L85-E. Other kits that utilize GM 245mm or 258mm core are available.

  • Build in a variety of stall speeds
  • Fast, easy assembly with predictable tuning adjustments
  • Fits 10.750", 11.062" and 11.500" flexplate bolt patterns
  • Chromoly steel turbine and impeller hubs for strength and durability
  • Fully-machined forged front cover and damperless piston add strength and durability
  • Sprag cartridge delivers more than twice the holding capacity of OE
  • Weld-on pilot adapts to many applications

Includes Sonnax base kit GM-RK-20M.

  • Impeller Hub
  • Sprag Cartridge
  • Turbine Hub
  • Pilot
  • Washer Vespel®
  • O-Ring Fluorocarbon
  • Seal PTFE
  • Front Cover
  • Damperless Piston
  • Clutch Plate with External Splines
  • Clutch Plate with Internal Splines
  • Thrust Bearing Turbine-side
  • Thrust Bearing Impeller-side
  • Unit Size: 265mm
  • Core: GM 265mm
  • Dampered: No
  • Lockup: Multi-Plate
  • Clutch Material: HTE
  • Turbine Hub Input Spline Count: 35
  • Existing Customers: Contact your sales representative.
  • New Customers: Fill out the form and a sales representative will contact you.

  • Gm rk 485 in combo

Sonnax Performance Converter Kits

Engineered to Deliver Builds that Last

Designed from the ground up to outperform OE and other aftermarket components, Sonnax has you covered with a full line of performance converter kits for gas and diesel vehicles. Offering the widest variety of options in the aftermarket, these innovative kits deliver customized performance and value.

  • Small/Large Diameter
  • Single-Plate/Multi-Plate/Non-Lockup
  • Dampered/Damperless

Choose the right kit for your rebuild!