We finish up our Abandoned History coverage of the long-lived UltraDrive transmission today. The pursuit of simplification, modernization, less weight, and better fuel economy lead to the creation of the electronically controlled four-speed A604 marketed as UltraDrive. The idea floated around at Chrysler in the Seventies and then was greenlit and put into production (before it was ready) by an eager Lee Iacocca. A case of unfortunate timing, the new transmission arrived in 1989 at a time when there was almost no exciting news in Chrysler’s product portfolio. Thus the UltraDrive name was coined by marketing, and the new and advanced transmission was featured heavily in the company’s PR materials in 1989 and 1990.

The UltraDrive’s debut version was prone to numerous types of failures because of fluids and sensors, build quality, parts, really everything. But engineers at Chrysler quickly massaged the A604 into the improved 41TE that was ready for use midway through the 1990 build year. UltraDrive was up and running within acceptable reliability standards per Chrysler. Clearly, it was time to create more UltraDrive variations!

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The recent Rare Rides Icons post on the 1990 Chrysler Imperial Super-K Gingerbread Cookie Edition generated a few comments not only about the subject in question but its four-speed UltraDrive transmission. It seems more than one of you wants a discussion – no – an essay on the UltraDrive. Wish granted! Here we go.

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