Packard Forum Index » Post-War (1946-54)

One feature all Ultramatics have is a lockup torque converter. At speeds above 25 MPH the torque converter locks up and you get the same performance gas mileage as a standard trans.

Two other advantages of this feature, (1) engine compression braking on downgrades, and (2) ability to jump start the car.

Only automatics with a REAR pump can be push started regardless of torque converter type. The rear pump supplies pressure to engage the bands and/or clutch PACKS.

CI Powerglide had a rear pump and can be push started. Not sure about T'Flites.

As long as there is oil in the torque converter then engine brakeing will occur in all automatics except may be Dynaflow. Not sure about dynaflow.

Thanks for correcting me about the Hydramatic plant destruction year and substituted transmissions among the divisions.

You're right of course in a technical sense, but now which do you suppose has better engine compression braking, a connection to the engine through a torque converter, or no torque converter slippage (because it's locked up)?

And there is a definite distinction between a torque convertor and a fluid couplng. My 400 will kick over between 15-20 mph according to my speedometer.

having just gotten back from a nice day of springtime packarding on some back roads with steep hills, i am thoroughly impressed with the ultramatic. shifting into low and using the lockup to engine brake is so cool, plus it is very controllable.

Owen, i would have to say locked up, because there is no slippage. the tranny input shaft is locked tightly to the engine instead of being allowed to rotate with slippage.

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Which is why any automatic can be push started, the only variable is the speed at which it obtains to go.

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TOTALLY FALSE!!!!

Like Keith stated, ONLY automatics with a rear pump can be push started. Without the rear pump there's no fluid pressure to engage the bands that will allow the driveshaft to be connected to the converter. I used to have a list of push start automatic transmissions but I don't anymore. IIRC, the Torqeflite trans from the pushbutton era can be push started, but the later ones cannot. (Which is why I can't understand that people who have a '56 Packard with pushbutton trans that convert to the TF don't use the earlier pushbutton version, it's a better trans, IMHO.)

Mikec wrote, "having just gotten back from a nice day of springtime packarding on some back roads with steep hills, i am thoroughly impressed with the ultramatic. shifting into low and using the lockup to engine brake is so cool, plus it is very controllable.

Owen, i would have to say locked up, because there is no slippage. the tranny input shaft is locked tightly to the engine instead of being allowed to rotate with slippage."

Mikec and Owen - I, too, enjoy driving my '55 Pat for the engine braking power of the T/U when the direct drive clutch is locked up. Although the hill is not steep enough to downshift into low, there is a hill with an "S" curve at the bottom close by my house. My former car, a 2003 Mercury Grand Marquis, had to be braked if coming off of this hill in "Drive" (because, evidently it was in automatic overdrive, to maintain a safe 40 mph speed down the hill and through the curve. In the Packard I can come off the top of the hill at 40, take my foot off the accelerator and the car will maintain the 40 mph to the bottom of the hill and I can power through the "S" curve without having to use the brakes. It had been so many years, when I first got the car, since I'd been able to do this in a car equipped with an automatic tranny that I'd almost forgotten about it. The two Infinitis that I'd owned had a semblance of it while the American cars equipped with auto trannys with automatic overdrive invariably gained speed on downhill grades when left in normal "Drive." The engine braking is much more pronounced with the T/U than with even the Infinitis and I like it - having grown to adulthood being used to using engine braking as much as possible to avoid fade on the drum brakes of that day. It is one of the things that I enjoy about the T/U. Although not an important consideration when driving newer cars with anti-lock disc brakes, it brings back the heightened experience of actually having to semi-understand the machinery under you and being part of the driving experience rather than just putting the thing in gear, turning the steering wheel and using the brake and accelerator pedals.

Just another old guy reliving his youth and revelling, a little, at actually having to drive a car again.

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I'm curious about this statement. I have owned several Chevy's from 57 through 64 and thought they were all good. Never a 58 but had an aunt that had a new one. I know the body's changed every year during those times but thought the overall quality was pretty much the same. Why have you singled out the 58?

After thought: Looks like maybe the Turbo glide transmission may be the reason to avoid the 58.