1955 Chrysler 300 standard transmission switch-a-roo questions

Forward Look Forum

  1. livininharrow

    livininharrow Senior Member

    Messages:
    1,098
    Likes Received:
    292
    Joined:
    Jan 21, 2012
    Location:
    harrow canada
    I like c bodys advice on hot rodding it. I love 4 speeds and have a couple in my cars. a hydraulic setup in my 35 Plymouth hot rod. has anyone suggested maybe a 2 speed powerglide just for shits and giggles. I am sure someone out there makes an adapter plate. I used to blow away my brothers 72 440 727 tranny fury with my 62 buick lesabre 401 nailhead with a powerglide. he is still pissed of to this day.
     
    • Like Like x 1
  2. Davea Lux

    Davea Lux Senior Member FCBO Gold Member

    Messages:
    3,610
    Likes Received:
    910
    Joined:
    Mar 27, 2017
    Location:
    Cornelius Or
    If going to a 2 speed automatic, you can also send the power flight out for some clutch pack and valve body modifications. This would eliminate the need for any adapters and it would be stronger than a power glide. Other choice was back in the day, B & M made an adapter for the 4 speed Hydramatic for the small hemi which was a pretty much bullet proof setup. All of this can get pretty expensive in a hurry though. The T-10 4 speed should fit the adapter for the T-85 transmission and would be a lot cheaper to set up.

    Dave
     
    • Thanks! Thanks! x 1
  3. Davea Lux

    Davea Lux Senior Member FCBO Gold Member

    Messages:
    3,610
    Likes Received:
    910
    Joined:
    Mar 27, 2017
    Location:
    Cornelius Or
    '62 Buicks had a Dynaflow as the stock transmission, Power Glide was the Chev transmission. The designs were some what similar. These two speed transmissions used the torque convertor to multiple torque to the wheels and were noted for smooth operation but sluggish performance in a passing situation. The 4 speed Hydramatic transmissions used in Oldsmobiles, Pontiacs and Caddys were much better in terms of over all performance but did not have a torque convertor and tended to shift much more roughly. These transmissions used a fluid coupling(s) in place of a convertor. (Jetaway hydramatics were twin coupling units)

    Dave
     
    Last edited: Jan 31, 2019
  4. CBODY67

    CBODY67 Senior Member

    Messages:
    3,527
    Likes Received:
    760
    Joined:
    Mar 27, 2011
    PowerGlide and DynoFlow have NO similarities. The Chevy TurboGlide was more like an inexpensive DynaFlow, though. The DF had no low gear unless you selected it manually, normal acceleration was "on the converter" rather than geared. The Buick Nailhead V-8s had enough low-rpm torque to make things work as well as they did.

    The main reason that the PG saw so much use in drag racing was that it only took about 15 horsepower to run it. Which meant that more power got to the wheels, although it would take a much deeper rear axle ratio or a looser converter to make it work well in those situations.

    If you look at the guts of any of the old HydraMatics, there's LOTS of metal in them moving around! Stout when built, with a deep low gear ration, but lots of quirks between all of the versions of them!

    One of my friends had a '62 LeSabre with the normal DF in it. A trans shop put a THM400 from a '65 Wildcat (THM400 factory-available behind the 401). It made a huge difference in how the car drove! So much so that his teenaged son wanted to drive it (even though it was a beige 4-dr sedan).

    I believe that the Chrysler PowerFlite (2-spd automatic) cars had a 3.31 rear axle ratio in them. Not quite deep enough to be able to use an OD in normal road speed driving. As I mentioned, most factory OD cars had 3.73 or 4.10 rear axle ratios. Which would make the "cruise" ratio in OD to 2.67 for the 4.10 final drive ratio. ONLY thing gained with the 4.56 ratio would be that you can drive the car MORE in 3rd gear without having to downshift at lower speeds. The cruise ratio would be closer to what you've already got, I suspect! Or you might find a 3.55 rear axle and not use the OD set-up at all! Just depends upon how much time, effort, $$$$ you want to spend.

    Enjoy!
    CBODY67
     
  5. Davea Lux

    Davea Lux Senior Member FCBO Gold Member

    Messages:
    3,610
    Likes Received:
    910
    Joined:
    Mar 27, 2017
    Location:
    Cornelius Or
    Agreed in part. The DF and the power glide shared much of the same design tech. The DF was a whole lot more complicated in that it had dual accumulators and variable pitch Stators. They shared, at least initially, very similar torque convertors and the hi-low ranges.

    That aside the torque convertors were products of the same design team as we there clutch and drum assemblies. Powerglide was the basic design, DF was the advanced "high end" by product.

    Power Glides proved more durable because of the simple, robust and basic design. DF were somewhat more efficient in terms of fuel economy in larger cars but were prone to more failures because of the more complex design.

    The Chev turbo glide and the Buick Triple Turbine Dynaflow were a disaster for GM. Both self destructed readily, Mostly because drivers use the "G" or grade setting to accelerate, a function which it was not designed for. Accelerating in this function which was designed to slow the vehicle down on steep down hill grades caused the breakage of the assembly and the failure of the transmission. That is why it only lasted a little over one production cycle.

    Also note the 15 horse figure to run the power glide was based on the late style aluminum power-glide transmission which was significantly improved from the '56 era cast iron units that this post started from.

    Dave
     
    Last edited: Jan 31, 2019
  6. CBODY67

    CBODY67 Senior Member

    Messages:
    3,527
    Likes Received:
    760
    Joined:
    Mar 27, 2011
    From what some owners of the TripleTurbine DynaFlow have noted, the cars do perform better than a normal DynaFlow. Buick spent millions designing it, BUT it came at a time when if an owner spent money for something, it had better be in plain sight for others to see, rather than something "unseen" except for an emblem or similar. Added chrome, two-tone paint, whitewalls, etc. were popular, as were under-the-hood upgrades, but not a "hidden" transmission.

    The TurboGlides had a weak case, from what I've heard. On some of the earlier ones, a friend said that if the car hit a dip too fast, it'd crack the case. The owners manual plainly stated that the "Gr" range was for downhill engine braking, NOT for acceleration. My uncle had a '61 Impala 4dr ht with a 283 2bbl and TG. It was smooth and all of that, with no durability issues, but by that time, most of the earlier issues had been resolved.

    The first PG did start in "high gear", with a manual low range. Like a DF did. By 1955, it was a full 2-speed automatic, though. There were many upgrades in DF with each new model year. Even such that some would not interchange with prior models. Of course, with Buick's TorqueTube Drive architecture, the "torque ball" (the pivot where the torque tube pivoted on the rear trans housing, as the rear suspension flexed up and down) was a constant source of fluid leaks as the cars aged. The RARE Buick of that time was the manual trans model. I have a friend who chases them, in part due to their rarity and their much better performance . . . until it needs a clutch replaced.

    Can't forget about the Borg-Warner automatics they built for Ford and other smaller brands of vehicles, even many 1970s Jaguar sedans. All of the early Ford transmissions were 3-spd automatics, but the Ford-O-Matics (not the 1960s Ford Falcon automatics) started in 2nd gear unless you floored the accel pedal, which would downshift it into low. The '57+ Cruise-O-Matics had their "dual range" "D" modes. D1 started in low gear and upshifted through the gears. D2 started in 2nd gear. LOTS of stuff to know about, back then! FOMs usually had 3.10 gears and the CMs could go down to 2.69 with a 352 V-8.

    Enjoy!'