GM TH475 Archives - Transmission Digest
Alto introduces steel plate for GM transmissions

Alto has introduced a new steel plate for a variety of GM transmissions. Applications covered include the 3L80/TH400, TH375, TH425, TH475, 4L80E and 4L85E for model years 1990 and on. The forward and direct steel plates have 14 teeth and measure .077 in. According to Alto, this updated steel plate has a set of 14