The Chrysler UltraDrive Transmission (Half I)

The Chrysler UltraDrive Transmission (Half I)


The current Uncommon Rides Icons put up on the 1990 Chrysler Imperial Tremendous-Okay Gingerbread Cookie Version generated a number of feedback not solely in regards to the topic in query however its four-speed UltraDrive transmission. It appears a couple of of you needs a dialogue – no – an essay on the UltraDrive. Want granted! Right here we go.

Chrysler had a protracted historical past with its TorqueFlite line of transmissions, utilized to rear- and front-drive automobiles. The transmissions have been many, diverse, and of handbook and computerized persuasion. TorqueFlite had its origins in 1956, and although the title went away circa 2000 it has since been revived. However the varied TorqueFlite transmissions, although dependable and long-lived, have been a bit primary of their format. The automated solely had three speeds.

Thus within the mid-Eighties, Chrysler determined to develop a line of transmissions separate from the TorqueFlite that they’d ultimately name UltraDrive. The brand new transmissions have been designed solely for front-drive, transverse engine purposes. The front-drive and transverse setup was all the trend on the time (nonetheless is), and after the debut of the Okay platform automobiles in 1981 appeared the best way ahead. The UltraDrive was to be superior, fashionable and was deemed the successor to the TorqueFlite a minimum of in front-drive purposes.

The modernity of the UltraDrive’s design was largely on account of its digital operation. It was one of many first computerized transmissions commanded by computer systems. Inside, there was an ECU (digital management unit) that decided shift factors by way of realized habits primarily based on how the automobile was pushed. The pc contained in the transmission activated solenoids to manage the hydraulics. Mentioned solenoids changed the numerous valves and servos that have been a part of the traditional operation of an computerized transmission.

Although the digital transmission was a complicated concept on the time, Chrysler had experimented with such a unit within the Seventies. Years later with monetary savior Lee Iacocca on the helm, Chrysler determined to pursue that transmission and extra “digital marvels,” which result in the employment of former NASA engineers. Their creations included the issue-prone gas injection and flaky digital dashboard of the early Eighties Imperial.

The Seventies check mule was a Plymouth Volare with a trunk stuffed with computer systems. It was this computerized Volare that fashioned the idea for the four-speed UltraDrive. Chrysler guess huge on its new transmission, and one individual within the board room, Iacocca, felt the know-how was prepared for its debut. It wasn’t, however we’ll get to that in a second.

And so it was in 1989 that Chrysler carried out the brand new A604 into nearly each front-drive automobile it made. From primary automobiles just like the Dodge Shadow and Dynasty to sporty automobiles just like the Daytona, mid-market automobiles just like the Lebaron, and even the corporate’s high front-drive providing the Chrysler New Yorker. A number of front-drive automobiles have been exempt from the A604, just like the imported Colts, the Omni, and the Aries that noticed its final yr in 1989. It was an enormous launch for an all-new transmission.

Aside from the brand new transmission, 1989 was a little bit of a lackluster product yr for Chrysler. Previous fashions like Aries and Diplomat have been on their method out, whereas the brand new Nineties product hadn’t arrived but. The top of promoting at Chrysler knew there wasn’t a lot flashy occurring, so he gave the A604 a elaborate title, UltraDrive. Then he put it on the forefront of the corporate’s advertising supplies.

The inherent issues with the transmission have been nearly instantly obvious. Given its rushed manufacturing, it’s typically believed the UltraDrive wanted about one other yr in growth. The A604s in new Chrysler automobiles typically failed after a brief time period, however there was extra to it than easy underdevelopment and mechanical unreliability.

It appeared there was additionally some lackluster planning throughout growth with regard to transmission fluid utilization. In all proprietor’s manuals of A604-equipped automobiles, there was a really useful fluid known as Kind 7176, or ATF+3. And whereas that fluid was particularly for Chrysler automobiles, there was one other suggestion within the handbook: Dexron fluid would work as an alternative if the ATF+3 was not obtainable. This data was duplicated on the transmission dipstick as nicely.

Sadly, the transmission was designed solely to work with the ATF+3 fluid. When homeowners took their automobiles into a store to have the transmission fluid modified, Dexron was used a lot of the time. Dexron brought on the transmission to fail, a lot to everybody’s shock. The problem didn’t smash the A604 and was typically resolved with a drain and alternative with the right ATF+3 fluid.

Chrysler realized that Dexron was not appropriate shortly earlier than the A604’s debut, because it put over 1,000,000 check miles on its new transmission. For no matter motive, time or cash, they didn’t change the labeling within the manuals, on the dipstick, or inform their sellers. A decade later, there have been nonetheless outlets that mistakenly put Dexron within the A604.

However that wasn’t the one widespread drawback, as a built-in digital “characteristic” brought on a lot shopper chagrin: Limp house mode. The sensors within the transmission detected when there was an issue someplace within the unit, and would default to limp house mode. One thing so simple as a briefly incorrect studying by a sensor brought on the mode to journey. As soon as it did the error code was saved within the ECU, and the A604 entered limp house mode. That meant when put in drive, the transmission used solely second gear.

The design was meant to permit shoppers to take their automobile to a service middle and stop additional transmission harm, or being stranded on the aspect of the highway. However this characteristic was not clearly communicated to homeowners or sellers. When an UltraDrive was introduced in to a service middle in limp house mode, the issue was typically recognized as a failure and remedied with a expensive transmission alternative beneath guarantee.

There was no backup plan for the transmission’s programming for limp house mode, solely second gear. Within the occasion a fault was detected in second gear, the transmission stopped operation fully and the automobile wouldn’t transfer.

A604 had a easy studying logic constructed into its pc, with a purpose to modify shift factors and harshness to how a driver behaved. It took a number of days to work out what a driver wished. This was not typically a problem if one individual drove their Chrysler day-after-day, perpetually. Nonetheless, if two drivers shared a automobile (like say with most household minivans) or if a automobile noticed many drivers in a fleet state of affairs, the transmission might by no means settle right into a sample. Thus when a driver bought into an A604 automobile for the primary time, the transmission’s realized habits was typically disconcerting.

Widespread failures have been publicized rapidly, and as proprietor complaints piled up Shopper Experiences took motion: They eliminated the Caravan and firm from their really useful listing. This apparently despatched Iacocca off the sting. Administration was known as to the board room in Highland Park and introduced Lee with varied knowledge associated to the UltraDrive’s failures.

Lee had a easy response and mentioned “Look, I’ve bought to go. I’ve bought to take a leak. Once I get again, I would like one individual answerable for this mess.” The job of fixing and re-engineering the UltraDrive was handed to 1 engineer, Chris Theodore. Together with his staff, the A604 was torn down and rebuilt. Engineering points have been compounded by poorly made inside elements, after which the models have been slapped collectively poorly.

Chrysler addressed the issue with a fast redesign of the A604, ending the engineering that ought to’ve been accomplished earlier than it went into manufacturing. The revised A604 was rapidly rebranded because the 41TE. It included completely different solenoids, new valves, revised sensors, and quite a few different modifications to make it extra dependable. Crucially, the 41TE had an ECU that was programmable.

There was nice stress from shopper teams for Chrysler to handle its transmission issues, as Shopper Experiences and the US.. Heart for Auto Security demanded motion. Iacocca approved a marketing campaign to contact all homeowners with UltraDrive transmissions, to get them to usher in their problematic automobiles. The corporate additionally determined to waive the $100 deductible for guarantee work, and prolong the guarantee protection to service loaners. There was additionally a buyback choice within the case the place an UltraDrive automobile couldn’t be mounted.

Guarantee claims died down rapidly sufficient after the revised 41TE changed the A604 model of the UltraDrive. Whereas 1989 and early construct 1990 automobiles have been problematic, by 1991 the transmission reached acceptable ranges of reliability. Round 500,000 automobiles have been constructed with the preliminary and most problematic model of the A604.

After its trouble-prone and rushed beginning, Chrysler bought lots of miles and plenty of derivations out of the UltraDrive. It’s almost assured that you simply’ve are available contact with an UltraDrive-equipped automobile in some unspecified time in the future in life. Extra on that once we end up in Half II.

[Images: Chrysler]

Change into a TTAC insider. Get the newest information, options, TTAC takes, and every part else that will get to the reality about automobiles first by subscribing to our e-newsletter.


Leave a Comment

Your email address will not be published.*



December 2022