Swapping 02M DSG with a newer?

Pie in the sky thought here.
My wife’s mechatronic unit is going on her ‘09 Jetta’s DSG. I did a basic settings reset using my VCDS and we did the calibration sequence. Boy was it scary starting out after the basic settings reset. Lots of flashing PRNDS and neutral kicks with solenoid errors in VCDS. But it’s been great so far since the adaptation sequence.
I want to get ahead of the game and buy another 02M and rebuild it in my basement and have it ready and waiting until it’s needed. But I was thinking, since I’ll be swapping the TCU do I need to stick with the 02M? Can I get a newer DSG that will bolt up and program it right? Or is it matched to the ECU and I shouldn’t even think about putting something different in there for fear of upsetting the DSG gods. And I should simply look at spending more on a new mechatronic unit and get that installed instead?
Am I barking up the wrong clutch? What does the DMF have to say (besides it’s clicking and clunking)?
Thoughts?
John

If the '09 Jetta is a TDI, it's likely the O2E DSG. You should stick with the same transmission code of the O2E, which is likely KQC(you can check your sticker or the top of the transmission to confirm). Some have tried switching to a newer DSG mechatronics unit or tried different DSG configurations and failed, there's very few success stories. Your mileage may vary.

I've torn down a DSG and tried rebuilding, but I couldn't get all the parts for it(some of the online ebay parts didn't give me a comfortable gut feeling). The failure rate on these is low enough that I wouldn't hesitate buying a junkyard DSG, slap on a new flywheel, new clutches if needed, and tune the DSG if you want some improvements. Usually the failure on the DSG for the internals is a bearing. Unless if you're having a nasty bearing whine, I wouldn't plan on even having a transmission ready on standby.

If you end up needing an M-unit, just replace the M-unit. The transmissions themselves are pretty good. You may need a DMF and some point too, but again, no reason to mess with the transmission (other than to just R&R it to get to the DMF).

I think you have a solution in search of a problem here.

Thanks Yes 02E, my brain fart there.

Thanks for that guys - it’s very reassuring. The DMF is making its ticking noises but it’s not bad for 150k miles. I’ll look at the mechatronic unit for now, get one and have it here, because I know its time is limited. I don’t have any noticeable whining inside the transmission so I’ll leave that be.

Thx again.

If you end up needing an M-unit, just replace the M-unit. The transmissions themselves are pretty good. You may need a DMF and some point too, but again, no reason to mess with the transmission (other than to just R&R it to get to the DMF).

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Hello Oilhammer (and any others)! I'm searching in old threads with a similar problem rather than make a new one, hoping you can help me understand my mechanic's thought process.

My 2010 Jetta TDI automatic (155k miles) has been acting up - at first it was just louder than usual noises while shifting and running, and then it started to have trouble shifting gears (particularly from 2nd to 3rd). While changing the oil, I noticed DGS fluid leaking under the car (connector was covered in oil). After taking it in to my trusted mechanic, they cleaned up the leaking oil and found a problematic gasket which they replaced. However, on the way home I lost power and finally it basically went into limp mode and I had it towed.

Mechanic is now saying they see codes P0735 (Gear5, Incorrect Ratio) and P2711 (Implausible gear engagement) as well as fluid apparently migrating through the electrical connector into the mechatronic unit. Based on the mileage on my transmission and possible clutch pack damage from the mechatronic failure, the mechanic has replaced swapping out the entire transmission assembly with a used (<100k) assembly from a parts yard.

Do you see this as a reasonable fix, or are they overreacting? Thanks!