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7 Series - E38 (1995 - 2001)

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Old 04-27-2011, 03:47 AM
BMW 3-SERIES BMW 3-SERIES is offline
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Join Date: Jun 2007
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Mein Auto: 2000 540i Sport (E39)
Post Information on automatic transmission - Common issues/fixes/diagnose

This thread is intended to help the E38 owner on the transmission, issues, and help to reduce threads on transmissions. You're not restricted from opening new threads transmission related.

This thread will cover some basic and more in depth information on the transmission. These topics include: ZF-5HP24A BMW E39/E38 SPECIFIC
  • Shifting Issues - Slow, Hesitation, Abrupt, and Missing
  • Forward Gears Failing
  • Reverse Failing
  • Torque Converter Issues
  • Symptoms of Failing Transmission
  • Hints and Tips of Maintaining Transmissions

I will try to cover as much as each topic as possible. Do mind that I did take time to get two personal friends, one who works at the dealer and other at a transmission shop to help answer these topics. Here we go!

Shifting Issues - Slow, Hesitation, and Abrupt:

Problems including slow shifts and hesitation is due in part or mostly to low fluid level, clogged fluid filter, dirty fluid or all the above. Sadly, most people don't think of changing the fluid because they are told that the fluid is "Lifetime Fluid" but ask yourself... Lifetime of what? The Car? Transmission? Most experts agree that a fluid change should be done 15,000-30,000 miles that includes a new filter always. Low fluid levels can also burn the clutches inside the transmission thus causing gears not to operate correctly (hesitation) or at all.

Forward Gears Failing:

Forward gears are really not as common as the reverse going out. But forward gears not engaging right away, kicks, or not engaging at all is a sign of Low Fluid, Clutch discs and/or bands are burn out worn, and finally Faulty Shift Solenoid. Fluid can be checked and added, but the other two means its rebuild time. These can not be fixed on their own. Majority of shops will require a rebuild. Specific parts may not be available.

Reverse Failing "No Reverse"

This may be the most common issue on the E38's ZF5HP24A. The infamous reverse failing is due to 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. Or like the forward gears, the bands and clutches are worn or burnt including low fluid.

Torque Converter:

Symptoms of a failing converter is slippage, shudder, and poor fuel economy. Slippage causes your car to resist acceleration while the engine continues to rev. The most common cause is low or overheated transmission fluid. Poor economy is due to TC's internal clutches are not locking up when they should be.

Symptoms of Failing Transmissions:

Let's say you start your E38 and place the car in drive and you feel a kick as it engages. Bad. Than you start driving along and your feeling it shift too early or too late at times. Signs of slipping. And say you get the occasional kick on a shift. Possibly Fluid and Filter. Remember, these cars were built to feel effortlessly smooth. So you should not even feel the transmission shifting or engaging. These are a probable start of issues of the tranny.

Hints, Tips and Maintaining a Transmission

First, lets get it out of the way. Doing a fluid and filter change is the most important thing. Doing this on time at the right mileage is critical and will prevent and could fix issues. As advised by transmission techs, when parking your car. Stop in Drive, place in Neutral than apply the parking brake, than shift into park (Don't let your car fall back on Park) This helps a lot. Helps save your Neutral Safety Switch and components in the transmission. Next, if you see products in auto stores claiming that they stop slipping and who knows what.. stay away. Majority of these products are not synthetic and could cause more damage than before. When changing fluid, adding to little could be just as bad as too much as the fluid does expand when its at its operating temperature (warm) Thats why I suggest taking it to a shop but with your own fluid (Esso, MaxLife, or Mobil-1 Synthetic ATF Fluid) and OEM BMW Filtran Filter. This is the only way to ensure maximum transmission life. Remember, these transmissions are picky and sensitive. And almost completely computer driven.

If You Must Rebuild and Hints:

If you have gone past the point of no return and a simple fluid change did not address the issue or you lost drive gears, a rebuild is a must now. I suggest a rebuild over used. Used is a risk. Did the previous owner maintain it? I always assume no. The good news of a rebuild is that BMW and ZF teamed up and updated/upgraded the parts inside your transmissions. Only a rebuild kit would have the new parts, so now you have future proofed your transmission. It is now stronger and more reliable than it came from the factory. Your transmission has drastically reduced its change of failure and issues. Request the rebuild shop to flash and clear your transmission and car ECU Computer - A must

Transmission Performance

There are few reputable performance transmission places. A few that I know and had great reviews from is IPT Transmission, Jasper, and TransSpecialties. These shops offer Stronger Rebuild Kits that includes better clutches, bands, and seals. Custom Valve Body that improves shifting speed and feel and a Performance Converter that are high-stall and much much stronger.

Well thats my lecture on the E39/E38's transmission. Hopefully this answered your question and prevents future threads on transmissions if its in here.

Credits go to Me and experience on ZF and Rebuilds, BMW Technician, and Transmission Shop Mechanic all of my friends.
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