Sonnax turbine stiffener plate GM-WS-39 is used to create a stronger turbine in GM TH400, 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 TH400 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 TH350 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

More From This Category

COMP Cams Cam and Lifters, Thumpr, Hydraulic Flat, Advertised Duration 279/297, Lift .494/.480, For Buick 400, 430, 455, Kit

COMP Cams Cam and Lifters, Thumpr, Hydraulic Flat, Advertised Duration 279/297, Lift .494/.480, For Buick 400, 430, 455, Kit

$943.70

Wilwood Brake Pad, D536, ProMatrix, Bedded, .575 in. Thick, 800 to 900 F, Medium Friction, Set

Wilwood Brake Pad, D536, ProMatrix, Bedded, .575 in. Thick, 800 to 900 F, Medium Friction, Set

$97.62

COMP Cams Camshaft, Xtreme Energy, Hydraulic Flat Cam, Advertised Duration 250/260, Lift .432/.444, For Chrysler 283-440, Each

COMP Cams Camshaft, Xtreme Energy, Hydraulic Flat Cam, Advertised Duration 250/260, Lift .432/.444, For Chrysler 283-440, Each

$602.88

DBA Rear 5000 Series HD Brake Ring, 380mm, For Brembo Replacement XA2.91.32/33 72 Vane, No Nuts Supplied, Kit

DBA Rear 5000 Series HD Brake Ring, 380mm, For Brembo Replacement XA2.91.32/33 72 Vane, No Nuts Supplied, Kit

$586.40

Sonnax Shim, F&S ZF4Hp22, A999, ZF4Hp18, Each

Sonnax Shim, F&S ZF4Hp22, A999, ZF4Hp18, Each

$1.30