Quote:
Originally Posted by Desert1957
Interesting, My RPO code was M40.
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Correct. M40 is the "non merchandised" RPO.
MX1 is the "merchandised" RPO.
The merchandised RPO is the one that is selected by the customer, and then the non merchandised RPO is computer selected based on GVW, powertrain, rear axle, etc - to choose the correct trans.
Sometimes it doesn't matter, but in the case of the two 3 speed manuals the computer will select the correct trans based on the powertrain configuration.
Said differently, the purchaser says "I'd like a three on the tree, please", so MM3 is chosen. The computer then selects M62 or M64 based on the other variables.
Quote:
Originally Posted by Desert1957
Turbo Hydra-matic 400
The TH-400 or Turbo 400 was a three-speed automatic transmission first introduced at the beginning of the 1964 model year in Cadillacs and Buicks (under the name Super Turbine 400). In the following year, Oldsmobile and Pontiac and some full-sized Chevrolets received it.
The TH 400s produced in 1964-67 were equipped with a torque converter that incorporated the Switch-Pitch variable-pitch stator, which allowed variable torque application at start off and cruise. These can be identified outside the vehicle by the kick down switch on the tranny which has two prongs instead of one. His concept actually came from the Buick "Twin Turbine" Dynaflow transmission used from 1955 through 1963.
The TH 375, is simply a TH 400 with a long output shaft that mates to the smaller TH 350 drive shaft yoke. This can be identified by "375-THM" cast into the tail housing. Internally the clutch packs originally had fewer friction plates. The 375 rating was a result of the smaller yoke and fewer clutch friction plates.
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That may be why I didn't notice. The TH400 had historically come in a long tail and short tail configurations (I have a long tail TH400 retrofit into my '63 Grand Prix. The TH400 in my Chevelle is short tail).
K