Race Porsche

By Astonish Articles

 An automatic transmission is just that- automatic, consequently most people tend to pay very little attention to it until a major problem rears its ugly head.

Picture the scenario- you are driving along in the lap of luxury, the satellite radio blaring and the heated seats on. You have become accustomed to the comfort level and great driving experience brought to you by BMW.

You decide to stop at the local convenience store on your way home to grab some ice cream for the kids and a bottle of water for yourself. Upon returning to your car, you start it up, check your rear view mirror, put the shifter in reverse and then the unthinkable happens- the engine just revs as if it is in neutral and the car goes nowhere!

This article deals with the reasons behind an unexpected loss of reverse in certain BMW automatic transmission equipped vehicles, specifically the 3 series and 5 series vehicles that use the ZF5HP19 or steptronic transmission. This includes the popular 323i, 323ci, 325i, 328i, 330i, 525i, 528i, 530i, X3 and X5 models well as some others built in the 1999 to present model years.

To eliminate confusion, this does not apply to vehicles equipped with the GM 5L40 E transmission, just the ones with the sometimes problematic ZF5HP19. The 5L40 E has some issues of its own that are beyond the scope of this article but are certainly going to be the subject of another.

The failure rate for these transmissions seems to be very high and is expected to become much more of a problem as time goes by.

Typically, the vehicle is working perfectly while driving forward but when it is put in reverse there is a complete and permanent loss of movement to back up.

Reverse is typically a major feat for any transmission to accomplish- imagine the demands that are placed on a gearbox as it is asked to reverse the torque of your engine so that you can back up your nearly 4000 pound vehicle.

By far, the most common cause of the reverse problem in BMW’s is the failure of the D-G clutch drum. Specifically, the snap ring that retains the D or reverse clutch breaks out of the clutch drum resulting in an inability for the clutch pack to apply.

The good news is that there is hope in regards to a proper repair. The factory has released an updated part that so far appears to be a permanent fix for this problem.

In our testing and in conjunction with several hundred successful repairs at our facilities, the new part seems to be metallurgically superior in several ways.

We have found that there is an improved radius area as well as slightly thicker casting. In addition to this, the grove that retains the snap ring is also relocated further away from the edge of the drum.

With this issue addressed and attention to detail in several other areas of the ZF5HP19 unit, the transmission can be repaired to “better than new” condition by a competent transmission rebuilder / remanufacturer. In fact, when properly repaired, the ZF gearbox becomes quite robust and can provide an almost indefinite service life.

For more information on Car Transmissions or to find a Used Transmission visit SWTransmissions.com

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“Carputers” Becoming Options On The Open Market
By Mike Trudel

 If your fingers itch for a touch screen even during the morning commute, there may be a solution — particularly when you’re carpooling in the passenger seat and have a minute to play. Vehicles are now being released with “carputers” or “carPCs” as an option, not just as a retrofit. A familiar type of “carPC” to most folks is a Global Positioning System (GPS). According to an online encyclopedia, a GPS device is much like a limited laptop running GPS software.

Basic Specs and Tech:

“Carputer” machines consist of a motherboard, processor and memory and data storage method, such as a hard drive or solid state flash memory. Interface hardware depends on non-distracting options to interact with the “carPC,” such as wireless protocols, which are commonly used to connect to GPS devices and mobile phones. Wirelessly connecting and transferring data to and from home computers is also possible.

A well-executed interface is paramount to the machine’s success, and its software runs the computer’s hardware. Good programming allows drivers to use their favorite piece of technology without being distracted. Common operating systems are available and nearly all are customizable.

Making sure “carPCs” keep their juices flowing is a slightly more complicated matter than it is for the average desktop or laptop. The danger lies in the sudden power drain to certain systems that occurs upon start-up or, of course, when the ignition is cut. To suddenly seize a computer’s supply, however, is risky; software can malfunction and data can be lost. To safeguard against this, a DC-DC power supply is often used, which provides a continuous, 12V power stream to the “carputer.” A DC-AC inverter can also be installed, but it tends to use more energy and produce more wasted heat. The right hardware and software combination allows the computer to sense when the main power source has been cut and use what’s left to safely shut down the machine.

Experiments have found that Internet users experience marked levels of frustration when a Web site takes thirty or more seconds to load. Bearing this in mind, imagine how quickly “carputer” popularity would decline without the relay circuits enabling the machine’s devices to start automatically. Without properly relaying circuits, devices such as amplifiers and screens would have to be started manually — something a portion of the general public doesn’t even know how to do anymore.

Before 2000, LCD character displays were the screen of choice for “carPC” builders. Commands were usually sent to the machine through a keyboard with this system. Soon, wireless serial port remotes were made possible, and small television screens became affordable. The majority of first screens were video input only. For over a grand a pop, though, these were hard to justify. Rapidly advancing technology and production increases have recently made touch screens available and affordable.

Lest one thinks these little “carputers” are all business, entertainment features have been added. “CarPCs” now bring nearly all the entertainment comforts of home onto that cross-country trek. Passengers feel like watching a movie? No problem. Playing a video game? Hook ‘er up. Download favorite music, tune in to satellite radio and map the next trip to Europe on advanced GPS software. It’s all there. No more “Maaa-om. Are we there yet?” “Pop in a movie,” says Maaa-om. Or, “do your homework,” which she downloaded from a desktop at home. At last — technology not only brings hope for peace and quiet but also a way to make sure no one gets too lost along the way.

The possibilities are nearly endless. After all, automobiles have already been introduced to the world of high technology. Consider infrared cameras, a variety of hands-free applications, cargo detectors, lane departure and side (blind spot) warning software — these technological offerings are all not only possible but are already being incorporated. Imagine the capabilities modern computers possess. Now imagine that in your car.

Mike Trudel, Freelance Writer.

Delphi Corp. is poised to apply its expertise and know-how to provide vehicle manufacturers and consumers with in-vehicle connectivity. To learn more about Delphi Corp., please visit www.Delphi.com/4Innovation or www.Delphi.com/4Connected.

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