20 GEARS August 2010

It’s Time to Shift Gears; The Magna Powertrain Transfer Case by Steve Garrett

members.atra.comwww.atra.com

Well, it’s that time of year again; time for your annual pilgrimage to the ATRA

Powertrain Expo! What’s new for this year? For one thing, this year’s Expo is going to be in San Antonio, Texas.I’ve been to San Antonio many times; in fact, the last time I was there I took my wife. You may wonder why I’d drag my wife to central Texas for an ATRA seminar. The answer’s simple: San Antonio and its surrounding area is one

of the neatest places I’ve ever been to. So, if you were wondering whether you should go or not, I can tell you that you’ll regret it if you decide not to attend this year’s Expo. And, after your wife finds out how terrific this trip was from the other wives that attended, you’d better get ready to start sleeping on that cot in your shop. So what exciting material will I be presenting this year? I’ll be doing a presentation on the Magna Powertrain transfer cases that made their way

into the market starting in 2007. The MP transfer cases replaced the New Process/New Venture transfer cases you’ve grown so familiar with through the years. A number of MP transfer cases are now on the market, in use by several manufacturers. The GM family of transfer cases includes manually controlled models 1222/1225/1226, electrically shifted models 1625/1626, and active transfer case models 3023/3024.

Figure 1

SPEAKER

GEARS May/June 2010 21

As you can see there are seven different transfer cases just for GM applications. What’s so different about these units? In a nutshell, the construction of the units is very similar to the NV design transfer cases you’ve worked on for years. But the internal operation of the shift mechanism is quite different from most pervious designs. MP units use a completely different design shift motor (figure 1). In addition, this new design shift motor requires a learn process to adapt to system condition and wear. You’ll have to initialize a relearn process if you replace the motor. What about diagnostics? They’re different too, because the electronics on this unit aren’t the same as they were on the NV units. In fact, many of the components that you’ve become so accustomed to over the years, such as the encoder assembly, aren’t being used any more. Are you curious yet? I hope so: change is good in our industry, and it’s always good to have a bit of curiosity regarding the products entering the market. Remember, your competitor who didn’t attend this year’s Expo probably won’t know this change even occurred, let alone how the diagnostics and service procedures have changed.So, while your spouse is having the time of her (his?) life in San Antonio, you can be preparing yourself for the future when it comes to servicing MP transfer cases. I hope to see “y’all” there!