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4L60/E (298mm) Performance Converter (Mounting Ring)

Part No. GM-RK-12

Adapts front wheel drive GM 245mm core to GM 298mm applications with 27 splines

View Instructions

Sonnax racekit GM-RK-12 kit allows rebuilders to put together a high performance lock-up converter. This kit is for use in 200-4R and 4L60 (700-R4) applications that originally came with the GM 298mm converter with 27-tooth input splines. The kit utilizes the GM 245mm core allowing rebuilders to assemble a high performance converter with a variety of stall speed and STR (Stall Torque Ratio) options at a low cost.

The kit is designed to work with early-model GM 245mm piston/damper assemblies. 4L60-E units with EC3 systems MUST use clutches with Woven Carbon or High Thermal Engaging (HTE) friction material.

High torque applications can overpower the torque capacity of stock GM 245mm single disc clutch and damper assemblies. The ability of this single disc clutch to handle a specific torque load is dependent on many factors, including the amount of input torque and the strategy that is used in applying the torque converter clutch. Sonnax does not guarantee that the capability of the 245mm damper assembly will be adequate in all applications.

  • Impeller Hub Heat-treated Chromoly
  • Turbine Hub Prehardened Chromoly, 27-tooth spline
  • Thrust Washer hard anodized aluminum, seals to the 4L60-E input shaft made for the 298mm converter
  • Pilot for adapting stock FWD 245mm cover for use in RWD 298mm applications
  • Mounting Ring for converting FWD bolt pattern to RWD 298mm bolt pattern
  • Flathead Bolts (3)
  • Unit Size: 10"
  • Core: GM 245mm
  • Dampered: Yes
  • Lockup: Single-Plate
  • Turbine Hub Input Spline Count: 27
  • Existing Customers: Contact your sales representative.
  • New Customers: Fill out the form and a sales representative will contact you.
  • Gm rk 12

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!