November 2008

If your 1955, 56 or 57 originally came with an automatic transmission, it had a shift detent bracket located at the bottom of the steering column under the hood. This detent positively locks the transmission in “Park” when engaged. The Tri-Fives originally came with a two-speed Powerglide or Turboglide transmission. For most custom cars and drivers, those transmissions are long gone. The original shift detent not only locks the transmission in “Park” but limits the amount of shift arm travel from “Park” to “Reverse”. When installing a three or four-speed automatic transmission like a TH200, TH350, TH400, or TH700R4; if the stock shift detent is used first gear on three-speed transmissions and first and second gear on four-speed transmissions cannot be engaged. The opening in the original detent can be filed open slightly to accommodate a three- speed transmission but makes it very weak. Many car owners decide to remove the original detent bracket totally which results in a real safety hazard as the transmission can accidentally be knocked out of “Park”! There is no way of opening the original detent to accommodate a four-speed automatic like the TH200 or 700R4. Eckler’s Classic Chevy has now developed a replacement shifter detent that has the “Park” detent in the proper location and allows more than enough travel to accommodate three and four-speed automatic transmissions.

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