Jump to content
Get the Cheers & Gears App! ×
Create New...

Computerization speeds 6-speed development


Recommended Posts

GM's Unprecedented Launch of 6spd Transmissions Shifts into High Gear
Posted Image

PONTIAC, Mich. - Transmission engineers at General Motors Corp. have given new meaning to the term "overdrive." By using high-tech computerized tools, they launched nine new fuel-saving six-speed transmission models - the industry's largest lineup - in just four short years. Furthermore, their use of this technology has shaved as much as six months and $15 million from the typical transmission development process.

GM transmission engineers use sophisticated math modeling, among other advanced tools, to not only design the transmission components, but also to predict and test their reliability, analyzing functions such as oil pressure and flow, lubrication distribution and shift quality.

"We are using computer-based tools in powertrain development for our global engine and transmission programs and seeing terrific results," said Tom Stephens, group vice president, GM Powertrain and Quality. "On our six-speed transmissions alone, we launched nine models in four years whereas we previously averaged three or four transmissions every decade."

Stephens said this pace of product development and first-time quality is having an impact in GM's gasoline and diesel engines, where analytical models also are used early in the process to improve design and functional performance.

"On our new 4.5L V-8 diesel, for example, analytical models were used to design and evaluate nearly 500 different piston shape designs during a 10-day period before we picked the best one. To evaluate this many designs without computer tools would have been unrealistic in terms of timing and cost to do with actual parts," said Stephens.

GM's computer modeling and use of common parts on the four rear-wheel-drive (RWD) transmission models reduced development time as much as 50 percent. In fact, 47 percent of the parts are shared among all of the RWD models; and the 6L90 transmission (used in GM's full-size pickups) shares 75 percent of its components with the 6L80 transmission (used in GM's full-size sport utility vehicles, the Chevrolet Corvette, Cadillac XLR-V and STS-V, among other models).

GM engineers use the high-tech tools early in the development process to identify whether the computer analysis is sufficient and if physical parts still need to be fabricated and tested. In some areas, simulated tests took only 48 hours versus several weeks, helping to eliminate, in some cases, the need for costly and time-consuming prototypes.

Development of the six-speeds began in 2003, with the first of the RWD models being launched in 2006. GM's extensive use of computer math modeling tools has enabled the company to develop the various six-speed models in parallel. "Our use of computer tools has improved the first-time quality of our transmission prototypes by five times over past programs," said Jim Lanzon, executive director of GM Powertrain's Transmission Engineering. "We've eliminated one of three pre-production hardware builds - essentially a complete set of prototype transmissions - and the associated physical tests."

Lanzon said the new 6T40 front-wheel-drive six-speed model launching in GM Daewoo's Tosca facility this month was developed by GM Powertrain's Transmission Engineering in Ypsilanti, Mich., and the math model was sent to GM Daewoo in Korea for final development and manufacturing.

"The 6T40 transmission was built in Korea from our math models, placed in the first vehicle and performed beautifully," said Lanzon.

Among GM's first six-speed models were RWD transmissions introduced in 2006 in the Chevrolet Corvette, Cadillac XLR-V and STS-V. All of the six-speed automatics for RWD and FWD/AWD were designed for maximum application flexibility, allowing them to be used in the greatest number of vehicles in GM's vehicle portfolio.

Shared traits among the new six-speed automatics reduce complexity, size and mass, including clutch-to-clutch operation that enables the six-speed to be packaged into approximately the same space of a four-speed automatic. The transmissions also share an overall 6.04:1 gear ratio, which contributes to their signature balance of performance and fuel economy.
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Who's Online   1 Member, 0 Anonymous, 41 Guests (See full list)

  • GMC Upsizes the Acadia for 2024; New 2.5L Turbo-4

    GMC caused a stir in 2016 when it downsized the Acadia in 2017 from its previous near-Yukon length. That downsize brought the Acadia down to be inline in size with the contemporary Jeep Grand Cherokee.  In the years since, the Grand Cherokee has grown and GMC is matching that with the 2024 GMC Acadia. Inches matter in this class and in that the Acadia gains (back) 10.6 inches in length and 3.2 inches in height. That equates to 80% more space behind the third row and 36% more space behind th


    Cadillac Refreshes the CT5 with an Updated Look for 2025

    Today at the North American International Auto Show in Detroit, Cadillac unveiled the refreshed Cadillac CT5 sedan.  CT5 retail sales have been on an upswing of late, increasing over 35%.  In a time when sedan sales are stagnating or disappearing entirely, Cadillac's positive numbers have given hope that the luxury sedan market isn't quite dead yet. The refresh of the CT5 begins with the exterior. A new larger, bolder grille is flanked by new vertically stacked headlamps and Cadillac's sign


    Ford updates the 2024 F-150 with More Standard Power, More Hybrid Production, and a New Tailgate

    Tonight at an event ahead of the Detroit Auto Show, Ford unveiled the updated 2024 Ford F-150. Starting in 2024, the F-150 will drop the base 3.3-liter naturally aspirated V6 in favor of the familiar 2.7-liter Ecoboost V6. This increases standard power across the line by 25 horsepower and a whopping 135 lb-ft of torque.  Additionally, citing a 28% increase in hybrid F-150 sales, Ford is increasing production of the hybrid powertrain to meet this demand. Ford expects to double the mix of hybrid a


  • Create New...

Hey there, we notice you're using an ad-blocker. We're a small site that is supported by ads or subscriptions. We rely on these to pay for server costs and vehicle reviews.  Please consider whitelisting us in your ad-blocker, or if you really like what you see, you can pick up one of our subscriptions for just $1.75 a month or $15 a year. It may not seem like a lot, but it goes a long way to help support real, honest content, that isn't generated by an AI bot.

See you out there.


Write what you are looking for and press enter or click the search icon to begin your search