1980 84 TRUCK Tu MANUFACTURING SOURCE TRANSMISSION STAMPING INFORMATION Continued Automatic Transmissions not interchangeable between 1979 and 1980 models must have D codes changed in accordance with the parts identification committee ground rules Thefollowing has been agreed to by the car divisions I Add the number 0 zero to designate model year after the ink stamped code letters on the transmis sion case the numeral is to be the same size as the code letter 2 lf any interim model year changes are made to a transmission which would affect established EPA gasoline mileage figures the part number and code letters must change lf part number changes should happen to result in depletion of available code letters then a two place code one numeric and one alpha can be used TYPE DESIGNATIONS WILL BE LOCATED AS FOLLOWS All 3 Speed Manual on top right hand side of transmission case Truck 4 Speed above power take off cover All 3 Speed Automatic on right side of transmission above filler plug Turbo Hydramatic on top right front SERVICE SEOUENCING FOR SERVICE TRANSMISSIONS WILL BE AS FOLLOWS y PARMA 00001 TO 14999 TOLEDO 15000 T0 24999 MUNCIE 25000 TO 44999 HYDRAMATIC 00001 TO 99999 HVDRAMATIC TRANSMISSIONS WILL BE NUMBERED WITH THE LETTER WAREHOU ING AND DISTRIBUTION DIVISION OF GENERAL MOTORS CORPORATION LT TRUCK 5ZA t REV 1 84 ss