Trans shifting point question

Discussion in 'The Garage' started by cybrfire, Jul 14, 2003.

  1. cybrfire

    cybrfire 1 ton status Vendor GMOTM Winner

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    OK, just wondering if I'm thinking this correctly. As the engine RPM increases the vaccum decreases and once below a certain point the trans shifts. Is that correct and true of all non electrically shifted transmissions? If not then explain please. May have a problem just trying to diagnose.

    Thanks.
     
  2. dyeager535

    dyeager535 1 ton status Premium Member

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    Probably in most GM transmissions (Powerglide, TH350, TH400) low vacuum increases shift firmness (high engine load condition indicator, increases line pressure as I recall) and the governor is what governs at what RPM the shift occurs.

    You can buy adjustable modulators (worth very little in RPM shift change) and you can modify the governor to alter shift point.
     

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