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10 years ago

Gr was used on TurboGlide transmissions, and meant Grade Reduction. It was to be used going down steep hills and such, but in reality, was just a fancy name for Low. We had one of these trannys on a '59 Bel Air.

nashambassador

10 years ago

Gr means 'Grade Retard' used for engine breaking on downgrades, Chevie 'Turboglide trans'

swanny711

10 years ago

On a standard transmission GR would refer to the lowest forward gear. GR meaning "grade". GR picked up the nickname of "granny gear" on account of how slow it is.

Sources: In the early 60's my Dad had an International P/U with a shift knob marked GR, 1, 2, 3 , and reverse

dirtydave599

10 years ago

One of GM's "better" ideas, Not a Powerglide trans. Gr stood for "grade retard" A trans brake for going down hill. Didn't work out as trans was still a two-speed, but people would manually shift using Gr as second gear, not good. Instead of rebuild, trans was replaced (upgrade) to Powerglide. Make sure which trans you have then get correct indicator. Hope this helps.......DD

retiredpartsman

10 years ago

the turboglide trans used the gr [ grade retarder ] to hold back the car on down hill grades. the trans was a series of turbines and had only one speed in the drive position , similar to the buick dynaflow .they were a problem trans for CHEVY and many were changed to powerglides .