Friday, September 10, 2010

PRND21... a variety of gear indicators from the 1950's and 60's

I think it's interesting to find that there were more than a couple ways for an automatic to name the gears. What was the S in PNDSLR? Was O in PRNODL2L1 for overdrive? Must have been. One of these has D2D1 and then L.... and another has DL2L1... what do you suppose the difference is between 2 drive gears and one low, versus one drive gear and 2 low gears?


  1. The "S" stood for second. The PNDSLR arrangement was used on GM Roto Hydramatic transmissions from the early to mid 1960's.

    1. Thanks! Say, how do you know all this trivia? Australian streetcars by model number?