Packard designed the Ultramatic for ultimate smoothness and not for fast performance. They felt that with the torque converter and by staying in a single gear the trans could still provide decent performance but would not have any of the jerkiness exhibited by other transmissions. Many of the other early automatic transmissions had an ordinary fluid coupling and those do not multiply torque so need to have some kind of shift. Packard even had an advertisement showing their nice smooth comfortable ride compared to lurches bouncing passengers as the other car went thru shifts.
It turned out a car with one of those other units might be halfway down the block before the Packard had barely cleared the intersection. Unfortunately, because the Ultramatic is not fast off the line when in high gear in order to try and keep up with the other cars a manual shift was something too many drivers relied on.
Drivers would put the car in low, pull away and then slip the gearshift lever to high keeping their foot on the gas. There is no synchronization between the gears to speak of in the orignal Ultras so when the lever moved out of low and into high the low bands might release fairly quickly and the engine raced because there was suddenly no load.
The high range clutch plates can take time to engage so with the engine racing, when they finally had decent lockup pressure they were already spinning and sliding against one another before they could fully lock together. The task of trying to pull the engine speed back down using only the high range clutch caused the plates to overheat and burn.
Worse yet was situations when low range was slow to release but high might be a bit faster. When that happened low and high would both try to be engaged at the same time putting tremendous strain on pieces inside the trans.
As more cars came with automatics Packard soon realized they were at a competitive disadvantage so tried to improve the situation. They revised the valves and made changes to passages in the timing circuit to improve the situation which is part of the later valve body. Even went to the point of releasing a
timing kit to retrofit to older units in trying to improve the situation but that approach was never completed to a fully successful degree.
All that work did lead to the late 54 introduction of the Gear start which was the precursor to the 55-6 Twin Ultramatics and was a viable solution to have a more competitive transmission. Unfortunately there were almost no changes to the mechanical parts inside the unit that carried power. A revised transmission designed for a low HP low torque straight eight got very little testing before suddenly being placed behind a high torque high horsepower V8 in 1955. Teething problems with the hydraulics for the new shift pattern, components that might be a bit small for the power they were expected to carry and the lack of testing soon came to light and what was considered a decent and reliable transmission quickly got a poor reputation. Most of the problems were fixed by 56 but Packard was out of time.
While the low to high manual shift is not something Packard recommended it can be done much more safely by letting off the gas when moving out of low and not stepping on it again until the car is completely in high. Granted that defeats the purpose of trying to get faster acceleration but at least there is less of a chance the transmission will leave you or some of its parts sitting in the road.
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