Gearbox Failure
 

Just over the weekend my dad's 4.6 came to a hault. He was driving along when he noticed a noise coming from the X. Then not long after that the X went into the trans fail safe mode which then wouldnt allow him to select gears or drive up an incline. So being that the vehicle is under warranty I had BMW assist come out and lift the X and transported to the dealership and upon inspection yesterday they have said that it needs a complete new gearbox, apparantly the trans oil was black and needed changed but on the last service at 50,000miles the dealership didnt do this. His 4.6 now has 55,000miles. Best thing about this is, I told BMW just before christmas that I though the gear change was hard on his 4.6 compared to mine, his also had the dreaded thump into gear every so often but of course BMW told me they checked everything and there was no problem, I guess another case of BMW thinking they know what's best!!.......NOT!!!! Anyway all I can say is, thank god he had extended his warranty, a possible lesson to be learned also is a gearbox oil change is something that SHOULD be done at around 40,000miles and to push your dealer to do it as it seems to be an over looked part of servicing the X.

Thanks for the tip Sudesh, I'll add that to my list.

Not sure if the 4.6 came with a manual or automatic transmission, but could you please specify which one you have? Thanks!

Also concerned about my tranny fluid.

-X5 3.0i automatic

Nice heads up!

So much for BMW's "Lifetime" fluid.

4.6's are all auto! Yeah I thought the same about the lifetime fluid after this happened.

Seems that it's a tricky situation with this lifetime fluid. Many of those that have replaced their trans fluid in their high mileage X5s have experienced failure within 10k miles; now here is your dad's X. Seems to me the best practice would be to change the fluid every 15-30k right from the beginning.

I have an '01 4.4 with 130k on it. I bought it with 35k four years ago. At 60 I asked the dealer about the Trans fluid and got the same answer. It's Liftime Fluid. I did not think about it much for a couple of years. Than I found this great site and wow, I was shocked at how many people are having problems with Trans Failure's. I just had the fluid and filter serviced. They put about 9qt's of fresh trans fluid. What a difference. I am now trading my 4.4 for an '03 4.6 with 57k and the first thing I will have done is the trans service.

Glad to hear your are changing the filter along with the fluid..something people usually neglect. It's worth dropping the pan to get this done.

Yea, if you're going to keep a vehicle in the long run, the ATF is not to be neglected. On BMWs, it's suggested by the enthusiasts that an ATF change be done every 30-50k. As for the automatics failing after the ATF, sometimes changing the ATF on a high mileage vehicle may do more harm than good. Then again, automatic transmissions are complex, unpredictable things that may or may not fail between 70k miles and 200k miles.

Buy a manual.

X5 2003 3.0D Auto Gearbox Failure
 

Hi, I have a 2003 X5 Auto 90K miles and the gearbox died last week, dealer tells me it needs a new one at a cost of 6K plus!!! Anyone had any success in getting BMW to goodwill the gearox. I have a FSH with the SUV and it has never towed anything or being off road _ (However I do live in Ireland and some of our roads are worse then being off road!!!!! ;))

Cherrs

Offalis

Engines are extremely reliable these days.

Automatic transmissions are another story.

This ZF box is used in so many luxury cars...if failures are truly likely, there will be many of them. They might be more likely in the X5 than other applications, because of the curb weight.

Once enough owners are enrolled in my research I'll be able to report how likely such failures actually are.

When I had my trans replaced they told me the fluid in the old one was in bad shape. I was told if the fliud had been changed I might not have lost my trans. I think at 50k you change the fluid.

Makes me wonder why the fluid was in bad shape. Does bad fluid cause the transmission to fail, or does a problematic transmission burn the fluid?

Both.

The fluid will get contaminated by a failing gear or bearing, or by clutch pack material. This is the usual failure mode. Then, people see contaminated fluid and believe that the fluid caused the failure when in fact it is the other way around.

If the fluid is burnt smelling, and brown, then it has been subjected to very high heat and the friction properties may not still be within spec. The different fluids specified for different transmission models have different frictional characteristics, made to work with the wet clutch packs. Fluid that is out of spec causes the clutches to slip, generating more heat, and you are heading for a failure.

With BMW transmissions, whether they are made by ZF or GM, I believe that the BMW electronics are often the cause of a transmission failure. A sensor fails, shifting controls don't work properly, and then a failure results. Given the history of other electrical problems on modern BMWs the control package is more likely to be a cause than the transmission itself. Automatic transmissions are actually very reliable devices, using the same technology for decades. What has changed are the control packages. The controls are often specific to the manufacturer, so a ZF transmission in another car may be reliable, but not so in an X5. Some newer controls have helped substantially; old transmissions had very perceptible shifts between gears. Modern transmissions have more gears, less shock when the shift happens, but also have an algorithm that reduces engine power (by changing timing usually) when the shift happens. That makes for a very smooth shift, and the result is less wear in the transmission.

I find it interesting that people talk so much about miles to failure in an automatic transmission, and comment on the variability. In my business we use heavy duty industrial transmissions in mobile equipment. Our predictors for planned component change-out times are just as often the number of cummulative shifts as they are the miles or the hours. Overloading is a factor, but shift count is a good indicator of wear-out for us. The transmission controllers keep that info; I don't know if BMW has any similar technology.

Great info, I appreciate it. This might explain why the Aisin six-speed transaxle has shift flare issues in some applications but not others.