Description
TH400 4L80E Forward and Direct 14 Tooth Performance Steels Number 031701BPS. (1)
TRANSMISSION: TH400 4L80E
PRODUCT TYPE: Performance Steel Plate (OAT .060″)
TH400 1964-95
4L80E 1990-On
Forward and Direct .060″ Performance Steel Plates (Forward and Direct Drums have 14 Splines)
Early Numbers ———————————————– Late Numbers
# 031701A Steel 12 Teeth ——————————– # 031701B Steel 14 Teeth
# 031701AK Kolene Steel 12 Teeth ——————- # 031701BK Kolene Steel 14 Teeth
# 031701APS Performance Steel 12 Teeth ——— # 031701BPS Performance Steel 14 Teeth
# 031701AXPS Anti-Drag Perf Steel 12 Teeth —– # 031701BXPS Anti-Drag Perf Steel 14 Teeth
The early Alto numbers are the late OE design with 8 full teeth and 4 partial teeth, this was done in
an effort to reduce cost and material. When used with the stock production engine, it will perform
without any problems. When used with hi-performance engines there is a chance for diminished
performance.
The late Alto numbers have a set of 14 full teeth like the early OE design which will enable the
steel plates to handle the increased horsepower and torque produced by hi-performance engines.
Note: This update will affect Modules and Power Packs that include these steel plates
