Trans slow to engage reverse
 

Hi all,
Hoping the collective knowledge bank can offer some suggestions regarding my dilemma.
I've had the X5 (2006 4.4) for about 4 months now. Noticed shortly after purchasing the car that the trans was quite slow to engage reverse from 'D' compared to other vehicles I've driven with a ZF auto transmission. I serviced the trans (dropped & cleaned pan, changed filter, cleaned magnets etc.) and have since changed the ATF twice to blend as much new fluid as possible in the system (using a ZF suited fluid). The fluid that came out was relatively clean, as were the pan and magnets, with only a modest amount of 'swarfing' (fine black or grey metal dust) evident.
The PO had the alternator swapped out about 3 months before I purchased the car and I've read that the six speed ZF may require a 're-flash' if there has been a big voltage drop. I have not yet done this though, as I'm quite a distance from the nearest BMW dealership, and believe this must be done via their diagnostic system???
On occasion, the transmission seems to 'hunt' or 'bump' a bit, when I'm cruising at urban speed limits (with little throttle pressure), as if it's changing between 3rd and 4th all the time. At first start-up (when cold) the transmission seems to 'hold' 1st gear for a long time, then grabs 2nd gear quite harshly. If I warm the car up (say for 1 or 2 minutes) this symptom doesn't seem to happen and all gears change smoothly. Again, these symptoms seem to correlate with what I've read about the trans requiring a flash of the mechatronics, but no where have I read anything about the delay in engaging reverse from drive - it takes like 1 or 2 seconds and is most disconcerting when I'm trying to parallel park and have a queue of cars behind me waiting to pass.
Any advice or suggestions from those who may have suffered similar problems would be greatly appreciated.

Sub'd


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Same. What's the deal?

You're not going to like my answer. You need to rebuild the trans.

BMW V8 No-Reverse – 5HP24 (A5S-440Z) Automatic Transmission, 540i, 740i, 840i, X5 | Bavarian Autosport Blog

You have a different trans, so my previous answer may or may not apply to your trans.

Thanks

How many miles on the odometer? Does the transmission ever go into "failsafe" mode with a mafunction message? These units are prone to bushing failure as well as the molded pistons, which would require overhauling the unit. I did one a month ago in a 2008 528i with only 110,000 miles on it. Needless to say, I'm not very impressed with the engineering for such an expensive automobile.

As mentioned in my original post, I have the six speed ZF in my 2006 model X5. Car has just turned over 130,000 kms or 80,000 miles. At no time has there ever been a malfunction message or has the trans gone into failsafe mode.
Reverse from drive takes about 2 seconds to engage, which is not normal in my experience. Also there's a slight 'bump' or what feels like the trans going from drive into neutral and back to drive, when cruising at 30 mph or 50 kph. It's hardly noticeable, but pisses me off somewhat, as I know this is not normal either....
Wondering if the mechatronics re-flash that I've read about might remedy some of these symptoms and if I need to take the vehicle into a dealer to have this done or can I do this via a scanning tool. Suggestions greatly appreciated.
At the end of the day, the car drives really well and I can live with these slight glitches, but being a bit anal, I would like to have the car as perfect as possible.

Search my threads. You don't need to rebuild. You most likely need new solenoids for the valve body. About $600 and a whole bunch of hours. The rough 1-2 shift when cold is about normal for these cars. Almost every v8 x5 I have driven has done this when cold. If your reverse is slow to engage when hot, could be solenoids are gunned up. I may have caused this on my car when I did my trans filter service. When I got the solenoids out, they had rubber filter type of material in the screens. You never know what someone did before you, and your solenoids may be in the same boat.

mine do this too, i thought it was normal