400 (3L80), AT-540, BorgWarner 310mm LU (A618, 47RH/RE, 48RE), BorgWarner 310mm NLU

Reinforcement Ring
Part No. GM-WS-39

BW 310mm LU (A618) and Allison AT 540/545 units require modifications for proper fit. See instructions for details.

View Instructions

Sonnax turbine stiffener plate GM-WS-39 is used to create a stronger turbine in GM 400, Allison AT 540/545, BW 310mm LU (A618) and BW 310mm NLU converters. The design incorporates a contour and reduced outside diameter for optimum fit to the turbine.

The Sonnax plate can be welded as-is to the turbine in GM 400 and BW 310mm NLU converters, but in Allison AT 540/545 and BW 310mm LU (A618) converters, GM-WS-39 must first be modified.

To weld GM-WS-39 to the turbine, a stock 350 transmission forward clutch piston may be used as tooling to hold it in place for tacking and welding. Tack welding four to six segments on both the inside and outside diameters of the stiffener plate should be adequate, however some may elect to weld completely around both diameters for maximum strength.

  • Contour designed for optimum fit to turbine
  • Enhances strength of turbine
  • Weld-in-place
  • Material: Steel
  • Thickness: 0.420"
  • Inner Dia.: 4.710"
  • Outer Dia.: 6.260"

Where to Buy

  • Existing Customers: Contact your sales representative.
  • New Customers: Fill out the form and a sales representative will contact you.
  • 400 (3L80), AT-540, BorgWarner 310mm LU (A618, 47RH/RE, 48RE), BorgWarner 310mm NLU Reinforcement Ring GM-WS-39