Article by Joe
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BMW "No Reverse" Transmission Problem
Author: Joe Sirugo | Posted: 04-12-2007
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
Subject: Technical Issues
Obviously you don't take the time to read consumer sites. I am yet
victim of the 2000 323i series transmission problem. My car just
not go into reverse. As many of the people on the below site
recall needs to occur. This is bleeding us dry and I bought my BMW
your reputation. Please - do the right thing.