Kit cars in the USA

 "Dedicated to American Kit Cars" Information about Kitcar Contact Kitcar         Home of American kit cars - Kitcar Kitcar articles All the latest kit car news Kit car discussion for the enthusiast


Kit Cars
Car Spec Sheets
Picture Gallery
Kit Car Clubs
Build cost estimator
Kit Cars for sale


CATEGORIES (articles) > Transmission > Automatic Gearboxes > Ultramatic Automatic Gearbox

Ultramatic Automatic Gearbox

Ultramatic was the trademarked name of the Packard Motors Company's automatic transmission introduced in 1949 and produced until 1956 at Packard's Detroit, Michigan factory.

1935-1948: Development

Packard's Ultramatic transmission was the creation of the company's chief engineer Forest McFarland and his engineering team. The magnitude of the accomplishment is illustrated by the fact that it was the only automatic transmission produced solely by an independent automaker with no outside help. Different devices like the Ultramatic were being tested and designed by Packard from 1935 on, but none sufficed the perfectionist engineer. The Ultramatic's development was halted as was all automotive work during World War II, but was picked up again in earnest during 1946. Packard, during this period, was suffering in competition with Cadillac, thanks to their popular self-shifting Hydramatic, which was available starting in 1941 and became very popular during 1946-1948. Packard at that time was only offering an Electromatic Vacuum Clutch option that was widely considered more troublesome, and finicky, than helpful. In 1949, Packard's 50th anniversary, McFarland's Ultramatic Drive became available at a $199.00 premium; it was offered at first only on the De-Luxe Packard Customs.

1949-1954: Ultramatic Drive

The Ultramatic was a hydraulic torque converter automatic transmission with a two-speed plus reverse epicyclic geartrain and torque converter lockup, called Direct Drive by Packard. The unit was hydraulically controlled with a "valve body," like most automatic transmissions before the advent of electronic control.

The original Ultramatic did not switch automatically between high and low gearing ratios; the driver selected high or low ratio through the column shift lever. The intention was that in normal driving, the high (1:1) ratio would be selected at all times, and the two stage, dual turbine torque converter (actually a total of four turbines were employed) used to reduce gearing for starting off. At a speed between 15 and 56 mph (depending on rear axle ratio which affected the rate of governor pressure rise), governor pressure eventually overcame the opposing throttle pressure, as determined by carburetor linkage position, causing the Direct Shift Valve to apply the direct drive clutch. This "locked" the torque converter, giving direct mechanical drive from the engine to the rear wheels and thus eliminating the power-robbing slippage of the torque converter at cruising speeds. The Ultramatic delivered the same economy and power as a manual transmission. With the lone exception of Borg-Warner, major automotive manufacturers did not generally employ a locking torque converter until nearly thirty years later.

The low ratio, meanwhile, was available for climbing and descending hills. Using low ratio, the torque converter lockup happened at a slightly lower speed as a result of reduction in the rate of the opposing throttle advancement, eliminating the problem of torque converter overheating that plagued early automatic transmissions in such conditions.

Ratio selection was through a column shift, with a lighted selector quadrant on the steering column showing the range. The positions available were Parking, Neutral, High, Low and Reverse (PNHLR).

After its initial year, the Ultramatic Drive became available on all Packard models, and was immediately popular. It continued with a Packard program of modifications to improve reliability until 1954, when it underwent a major upgrade to both the power transfer and hydraulic control components reconfigured to give low gear starts automatically in the added Drive range. Many Packard owners had complained of lackluster acceleration, and had discovered that starting off in Low ratio and switching to High while on the move gave a much brisker pickup, but the Ultramatic handled the actual manually shifted transition from low to high poorly. By 1954 both the Borg Warner and Chevrolet Powerglide in addition to the aforementioned Hydramatic, performed ratio switches automatically while Buick's Dynaflow continued using high gear starts until its demise after the 1963 model year.

1954: Gear-Start Ultramatic Drive

Packard's new Ultramatic model introduced in the middle of the 1954 model year, was officially called: Gear-Start Ultramatic Drive, offering a new selector sequence on the column shift: 'D', for Drive, placed in between High, now represented with a simple dot, and Low (PN•DLR). In this new DRIVE range, it would use the low ratio and torque converter to start off, switching to the high ratio and ultimately to direct drive as the car accelerated; effectively automating what many Packard drivers had been doing manually with the older Ultramatic Drive.

1955: Twin-Ultramatic Drive

In 1955, Packard switched to a new V8 engine from its traditional straight-8, and launched a new evolution of its automatic transmission at the same time, the Twin-Ultramatic Drive. McFarland, his assistant John DeLorean, and their team were not satisfied with the improved pick-up of the Gear-Start Ultramatic, and modified the angle of the converter "pump" to allow a higher stall speed thus increasing the torque multiplication better suited to the torque curve of the new V8 engines. In addition a slightly higher stall converter was produced for the sportier Caribbean model due to its use of two four-barrel carburetors. The Gear-Start's ability to start in low range and switch to high automatically was retained, but the selector quadrant indicator was altered and PN•DLR became PN'D'LR to better reflect the dual drive range capability of this transmission, all the better to compete with Hydramatic. Functionality was the same; the first Drive position, to left of the 'D equated to High on the Gear-Start Ultramatic, while the second, situated to the right of D', was equivalent to the Drive position on the Gear-Start, giving the driver the option of starting in either High or Low with automatic upshifts, ending with Direct Drive engagement of the torque converter, thus the Twin- designation referred to this dual Drive capability.

The Twin-Ultramatic suffered many "teething problems" when introduced, which did significant damage to Packard's reputation for quality and reliability. However, over the years it's become clear that Packard's initial Twin Ultramatic problems weren't out of line with any other new contemporary designs and the engineering department's program of running changes and updates greatly increased its functionality, excepting driver abuse through excessive application of the higher torque V8's power potential. Lower-powered models in the Packard range and those sold to American Motors suffered fewer problems. Exacerbating the difficulties, Packard was hemorrhaging experienced dealerships, which meant that many 1955 Packards were not being maintained to the previous high standards.

1956: Ultramatic and Touchbutton Ultramatic

Catalog illustration of Packard's Touchbutton Ultramatic's driver controls

The year 1956 saw a further development of the transmission in a major redesign of a majority of all individual transmission components, including re-calibration of the shift pattern producing an improvement of shift control. In addition there was a nomenclature change which reverted to the plain name of Ultramatic Drive. This year also saw the selector quadrant undergo yet another change to become: PNHDLR in order to further clarify the two drive ranges and accommodate the soon to be released push button control pod. In addition General Motors threatened lawsuits regarding dual "Drive" ranges, because of their "Dual-Range Hydra-Matic Drive" of 1953.

In addition to the numerous upgrading, small but important changes to shift linkages, better build quality, and stricter tolerances restored Packard levels of reliability to the 1956 transmission. Also new that year was an aluminum transmission casing, making the Ultramatic 90 lb (41 kg) lighter than its competition. Future transmissions from all manufacturers were to follow Packard's lead.

Packard decided to offer a "Pushbutton Transmission Control" for the 1956 series called "Touch Button Ultramatic". This was standard on the 1956 Caribbean, and was a $52 option on all Clipper and other Packard models. The mechanism was built by Auto-Lite, a major Packard distributor. A thick arm off the side of the steering column extended to the driver's right about 6 in (150 mm), replacing the regular shift lever, with a rectangular pod with six buttons for selection. The bottom row of buttons offered Park, Reverse and Drive, while the top row contained the Neutral, Low and High buttons.

The system was electrically actuated, rather than Chrysler's mechanical pushbuttons, and was troublesome from the beginning. The electric shift motor proved insufficient to move the car out of Park on a steep hill, and would pop the circuit breaker; electrical contact problems, wiring problems and other issues were prevalent even when new, and worsened with age. When the contract was cancelled after Packard production ceased, Auto-Lite destroyed the tooling, making spare parts for the system unobtainable.

Although true Packard production ceased after the 1956 model year, the Studebaker Corporation continued to have service obligations to Packard owners, and the 1955 Twin-Ultramatic and the 1956 Touchbutton Ultramatic were a recurring problem.

Historical perspective

Packard's successful development of its own automatic transmission was unique; no other independent (non-Big Three) automaker managed such a feat. The company's worsening situation throughout the 1950s, however, did not permit sufficient funds to keep up with the transmission development of the larger companies; Packard's attempts to update the Ultramatic were not sufficiently tested to iron out the problems, and those problems did damage to the company's reputation. Some automotive historians have argued that Packard should have dropped the Ultramatic after 1954, and purchased a more modern transmission design from another manufacturer but such opinions prove worthless when considering Packards use of a locking torque converter was not only up to date but ahead of its time. In addition the only true new modern transmission to appear was the Dual Coupling Hydra-Matic but that didn't appear until 1956 and had serious teething problems of its own. In retrospect Packard's Twin Ultramatic's most serious design flaw was during the low to high shift transition where a poorly timed high clutch application and low band release over much of the allowable upshift range resulted in many premature high clutch failures. This situation resulted in an unusual sensitivity to individual driving habits determining useful clutch life. Therefore while this transmission was certainly designed to physically accept a high torque V8, its control system likely needed another year of development.

Surviving Ultramatic transmissions

The efforts of Packard enthusiasts since the company's demise have kept many units in service and have, in fact, improved the reliability of the factory originals. Better modern transmission fluids, aftermarket transmission coolers, and improved rebuild parts combine to this end. Packard transmission rebuilder Ultramatic Dynamics offers a rebuild service as well as parts.

Related Articles

CATEGORIES (articles) > Transmission > Automatic Gearboxes > Ultramatic Automatic Gearbox

Search for keyword     

This content from Wikipedia is licensed under the GNU Free Documentation License.

copyright 2024
terms and conditions | privacy policy