Replacing megatronics is not difficult , surley not a complete transmission problem , alternator also easy enough to do .
Your mechanic is certainly putting the beef to your but .
Find another shop .

 

It's a shame you don't feel like you could do the work and replace the transmission yourself! There are probably dozens of YouTube videos on how to do and and you could do the alternator at the same time.
You would be surprised at how easy it can be to swap out a tranny.

 

Based on the code, I believe you just need to replace Solenoid #4. If I were you, I would just replace all the solenoids and all the seals plus ATF change.

Not many shops are super familiar with working on the transmission. Most will just tell you to replace it.

This guy on YT seems to have done it and he is in S. Cal.

https://www.youtube.com/c/ShopLifeTV

Maybe you can email him.

 

Here is what your parts should cost. in addition to the solenoids, you also need fluid, pan/filter (see fluid change kit), sealing sleeve/adapter, and when done reset transmission adaptations. ZF Solenoid Kits

I'd email ctsc, and see if they can point you to a guy who knows what he is doing and is willing to rebuild the mechatronics or at least look at it before coming to that conclusion. Hope you don't need your car back fast, this is why I don't work on cars for other people. drop it off, and I can have it back in 6 months.

But if you do need it back fast, throw all those parts at it, so they are ready to install. Should only take him a day. I'd verify those codes one more time before doing anything. A good indy can do that, or a friend with ISTA+

I don't know what you boys over in CA mean by Southern CA, but over here in TX it means close to the border. these guys have a recommended place (up?) in Thousand Oaks ZF Parts Installer

 

I serviced my own Mechatronics unit on my 2006 E61 a few months ago, the first time doing something like that since dropping the engine on my 1970 VW Bus back in 1989. While it wasn't "easy", it also wasn't that hard. With a 2nd person to help, did it in about 4 hours. Getting it safely jacked up was half the battle. The rest wasn't that hard.

I didn't replace any solenoids, but from the Youtube videos, doesn't look that hard. If you really want to keep the car as long as you can (which I'm in the same boat), I'd say go for it. It was a rewarding experience, and gave me the confidence to try bigger projects in the future.

I was going to rebuild my transmission, but was guided towards just servicing the Mechatronics unit from this forum. Glad I did, much simpler. Probably gave me another 1-2 years I'm guessing.

 

Holy cow do not replace that transmission. Why do transmission shops always want to throw new transmissions in at huge expense when 90% of the time the problem is easily repairable?

As many others have mentioned, a Mechatronics service that involves replacing the solenoids and a few check valves (in addition to the fluid and filter) is very DIY-able. This video from M539 Restorations has a great overview of the process.

 

It probably goes without saying, but if they change the alternator be sure they change/replace the $3.00 gasket that invariably leaks and costs hundreds in labor to access and replace.

 

Not sure I follow. Although the alternator bracket gasket should be replaced preventatively, it is hours and hours of more labor versus replacing just the alternator. The alternator can be replaced in 30 minutes. Getting the alternator bracket removed and reinstalled is a much more complicated process. It took me about 10 hours.

 

Honestly, it's time to let it go. I had the same car, difficult to let it go, but it was time.

 

Get rid of the whole car because the Mechatronic unit needs a service? That's the dumbest take I've read in a long time.

 

As others have stated. The mechatronics just needs to be serviced. I performed it twice on our 2007 530xi with 260k miles on it now.

Ralph

 

I wholeheartedly agree with those suggesting doing a Mechatronics refresh, and would suggest replacing that one shift solenoid (rather than all of them, though it's not going to put a dent in the amount your mech quoted). Mechanics like to make lots of money and take no risks, so much better (to them) to just soak you for a new tranny rather than have to accurately diagnose and fix a transmission for much less money (which takes skill).

 

I've heard ZF has a few service centers in the us. You might see if you can find one. I've replaced solenoids and seals on one of our cars and it wasn't an awful job. There is a good tutorial at www.thectsc.com and factory parts. I bought the solenoid kit and seals there to have original ZF parts. Transmission service requires the car to be raised and level. I did ours on jack stands.
The alternator overvoltage can be addressed with a new regulator I suspect. I changed ours on the car but it is a 6-cyl.
BTW, ZF transmissions are built like tanks in my opinion.

 

BTW, ZF transmissions are built like tanks in my opinion.

This is important... It's clear from hanging out here that actual fatal internal (non valve body) failures are pretty rare, even though the E60 vehicles are long in the tooth, and many haven't been maintained properly, partially due to the idiotic "lifetime fluid" sticker / claim by BMW (one which the transmission manufacturer, ZF clearly disavows).

Obviously, a tranny that's slipping in a given gear is toast, but it seems that the problems are overwhelmingly due to aging seals and occasionally bad (or dirty) solenoids. This is the kind of situation that allows those of us who twist their own wrenches to pick up problem cars for chump change, and usually fix them for a small fraction of what the PO was quoted by the dealer or indy shop.

 

Agree entirely. And yeah, the $10k quote to the PO to replace the tranny in my 2011 Mercedes GLK resulted in him selling it to me for chump change (it cost me around $1k to repair the transmission, which has been perfect for about 20,000 miles so far). As a result, I should be able to drive it for 100,000 more miles and then sell it at a profit. ;-)

 

Order a new solenoid kit, transmission filter/pan, fluid and the various rubber parts that need to be changed. Drain, drop the tranny pan, valve body and change out the solenoids. Replace the rubber parts and reinstall. It is a few hour job and can be done easily on jack stands. I figure $600-800 with filter and fluids.

 

Howdy,
I Believe that your car has the 6HP26 Valve body.
Here is a video about the Mechatronic Solenoids on Jack Stands
Part 1

Part 2

550 Mechatronics 6HP26 is a bit different than the 6HP19

Detailed View of Valve body split open