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

Thanks for all the replies and suggestions.
I've read through many posts about these problematic six speed ZF auto transmissions on a number of sites (these trannys are used in a multitude of vehicles). In most cases, the problems seem to be caused by either a faulty torque converter, faulty valve body, clogged filter/s, lack of service (leading to clogged filters), a great deal of towing, or simply not having the correct software programmed. It seems that many of the X5 V-8 models with this transmission suffer these problems (and other problems too). I have another vehicle with the five speed ZF transmission and it is faultless. That said, I've owned that vehicle since new, so know what/how it's been driven, unlike my X5 which I think was used to tow a boat or possibly something else quite heavy judging by the wear on the tow ball.
Irrespective, the transmission does NOT slip, pulls hard and does everything it should do, except for the slow engagement of reverse and harsh shift from 1st to 2nd when cold. I'm hoping that a re-flash of the mechatronics will cure these problems but I would still like to find out if I can do this myself or I need to take it to a BMW dealer to have this done? I hold little faith in the local dealers as I've already spoken to them about this issue and their answer was "you probably need to replace the transmission as they're a non-serviceable part"... WTF?

BMW dealers will not fix your trans, they will install a rebuilt trans at considerable expense. I would look for an independent trans shop with knowledge of the ZF trans.

My trans also functions very we'll aside from the reverse lag. (And the motor mount induced symptoms) which should be gone now.

Also does anyone find the position of the gear selector to be off? I'm used to it now but while test driving and the first week or so. It really bothered me. As well as a friend of mine who took it for a ride right after I got. Like it doesn't go as far forward as it should, looks like it's in R when it's in P. Anyone else?

There should be adjustment in the selector under the vehicle, where it connects to the transmission. It may have been improperly adjusted due to previous work on the car and/or might just need to be adjusted properly. Should be an easy fix but may require a second person (inside) when you loosen/adjust the selector rod to advise when it's sitting where it should be.

Ok thanks. I'm going to go out and poke my head around a little bit at other x5's first but I think it's off a little. The indicator does line up properly, but the position seems off.

The no reverse with a bad solenoid is more a GM tranny issue and not a ZF tranny issue. Not saying that it can't happen on a ZF tranny.

Here's a link to more info on BMW no reverse issue.

* No-Reverse Solution For GM Transmission * - E46Fanatics

Here's a list of shops that will rebuild a BMW tranny.

BMW Reverse Transmission Problems

Transmission symptoms can be misleading. Before I did anything more than you have I would take it to a well recommended transmission shop that has experience with your particular transmission. Depending on what is wrong you can then decide if you want them to fix it or if you DIY.

You may have missed this guy. Even though you posted in it.

http://www.xoutpost.com/bmw-sav-foru...y-3rd-4th.html

Thanks for the link SlickGT1 - made for very interesting reading and could be the road I must travel... Not too sure I want to take this path at this early stage of ownership, as I'm enjoying the ride too much at the moment to park the car up for any length. It's winter here now and as the wet weather progresses I may bite the bullet and pull the transmission apart to investigate, swap-out the solenoids etc. and revert to 'another' car as a daily... that said, my wife would not be impressed if I started to pull the X apart after only 4 months of ownership... I can hear her now "you haven't bought another lemon have you"?..."why are you pulling this car apart already"?..."here we go again"... So to keep the peace, I'll live with the transmission as is for a while, then delve into the problem when I've researched all possibilities, sourced parts and prepared my workshop for the task.

KVC...I realize which unit you have. I've been in the transmission business for over 35 years. It is a ZF6HP-19. My advice to you is DRIVE it, and not worry. When it breaks then you'll know what to do. Good Luck.

Herbert Boensch
Transpro Transmissions
Houston, Texas

Probably the best advice I've had from anyone! Thanks mate :thumbup:

Perhaps a new or rebuilt valve body will fix the problem.

http://www.automaticchoice.com/uploa.../95740-01K.pdf

You can perform the vacuum test as outlined in the PDF to see if this is the problem.

All I'm saying is, if there's no codes and no major malfunctions, then the best course of action is to drive it and NOT spend money needlessly trying to chase a few glitches....it will break you....LOL

It is actually not that big of a deal. I did it in one day. Not sure how many hours, but started and finished in normal hours. Took my time, sticking all the screws into cardboard to make sure I know where they go back in. I can't imagine being in the city, and having to park constantly, while waiting 2-3 sec for reverse to engage.