I am letting the dealer do it. Too much headache for me. It just sucks becasue the trans, spark plugs, belt (possibly), and oil change are all hitting at the same time.

 

Spark Plugs change isn't that hard - should take about an hour or two maximum.
Belt change should be no more than 15 minutes.
Oil change is definitely a DIY - especially if you have mityvac. Even if you do the oil change via drain plug, it still is not that bad - half hour.

All the above assumes you have the right tools. Once you buy the tools, they'll be with you forever. I highly suggest you do the spark plugs, belt change, oil change.

 

A while back, my car went into 'safe-mode' all of a sudden and a dreaded "Transmission Failure" warning appeared across the iDrive screen, whilst I was just about to overtake another vehicle on a major UK motorway; very scary!

I limped into a stealership who diagnosed a leak in the 'sealed for life' transmission. They replaced this and the oil sump at significant cost. Took them all day. They finished, came to me in the waiting room and told me there were still problems and I would need either a new metronics unit or a new gearbox! I wanted a second opinion so went to another stealership closer to home and after a diagnostics, it appeared I did not need a new metronics unit or gearbox, all that was needed was one of the connecting pins on the gearbox to be fitted correctly! They done this for me and internally-billed the other stealership for their funk-up!

Once everything was done, car felt smooth and a pleasure to drive again bar a few more grey hairs!

 

Hi, can you elaborate on what was fixed on your transmission? There is an electrical connector (aka bushing) to the conductor plate (aka mechatronics). The connector can leak trans fluid due to the failure on the o-ring. Are you referring to this?

I am well verse on the Mercedes trans conductor plates and electrical connector bushing leaks. I am trying to understand if the fix done to your trans is related to this electrical connector.

 

For context and clarity, when I took the car into the stealership, the "Transmission Failure" message was displayed across the iDrive screen. There was a loss of power as the car went into 'safe / limp mode'. The stealership checked this and discovered a transmission oil leak. The gearbox sump was removed and the sleeve and sump were replaced. The parts that were changed were as follows:
[1] 24117571227 (Oil Pan)
[2] ZLU13 (M1375.4 Auto Gearbox Oil)
[3] 24347588725 (Seal Sleeve)

Once this work was complete, I was advised by the service advisor that the fault was still apparent in the mecatronics unit which would either [1] require a new MU or [2] a new gearbox. I wanted a second opinion. The next day I took the car to another stealership and they diagnosed the problem as an incorrectly installed sealing sleeve. They then rectified this.

I feel that the mis-diagnosis and incorrect fitting of the sleeve connector by the first stealership was shocking and unacceptable. I took this matter further with BMW UK and the original stealership and eventually received compensation and an apology. On a related note, BMW have documented something of importance in Service Information SI B24 08, 06 Jan2009:

"In some cases, the incorrectly installed sealing sleeve may permanently damage pins in the Mechatronic connector (X8500). In such a case, the Mechatronic module has to be replaced (pin repair is not possible)."

The stealership who rectified the problem took photos of the incorrectly positioned sleeve and compared this to a correctly fitted one on another vehicle they had in the workshop at the time. This was used to show the original stealership had made a mistake. For further clarity and a visual reference, I have attached these photos to this thread; a red rectangular box depicts the sleeve in each photo. The first photo shows a correctly fitted sleeve and the second shows my car before it was rectified by the second stealership.

I trust this update adds a little more clarity.

 

Percy, thanks for the details on the trans work done on your car.

 

A pleasure. I hope this helps in some way.

 

They are advertised as sealed for life tranny's, but if you ask they will service it with a filter and fluid change. In the U.S. they are not allowed to get into transmission repairs though other than the fluid change. They replace the transmission and then send it to Germany for them to handle. FYI

 

My new to me '04 545i had a transmission service before I got it... going in to drive and reverse is slow (2 seconds) before the gear engages... there is also a weird noise like a loose chain drive when I start accelerating very softly either in drive or reverse and it goes away around 1100+ rpm... Is this something to do with maybe fluid level after this very recent service or a linkage issue. Another thread the poster noted (I believe dennism) that it would be related to general wear and tear (she's an '04 with 105,000km lady-driven suburban kilometres)