Quick Service on GM Hydra-matic 350 and 400 Turbo Hydra-matic Automatic Transmissions
The GM Hydra-Matic 400 series automatic transmissions were a proud badge of General Motors advanced and very reliable automotive technologies and engineering. The 400 series itself was installed in varying automotive products of the General Motors GM divisions’ products from the years 1969 through to 1976.
The Hydra-Matic 400 itself spurred on development of the Super Turbo 400 (THM 400.) A favorite still in the drag racing and auto racing fraternities – where it is proudly referred to as the “Turbo 400”, the tranny went on to propel down the roads and highways a bevy of established and even luxury automotive products including Ferrari, Rolls Royce & Bentleys, and domestic auto products such as Jeeps and early American Motors Sports Utility SUVV innovative models.
Yet the origins of this piece of Americana automobile history – still highly regarded today on the automobile racing circuits essentially developed and morphed from its predecessor the Turbo Hydra-matic 350 . 350’s were first installed in GM factory products in 1969 while they did run fully to 1976. The 400’s ran from 1969 as well and also made it into the mid 70’s.
First step of quick service for this unit series is to check fluid levels. Fluid levels should be at the “full “mark with transmission at “normal operating temperatures”. With cold fluid, the level should be approximately
