Gearbox woes W209 320

[jungledave45]

Ok so here's the story so far... started up and died immediately a couple of times a few weeks ago for the first time ever, started randomly changing gear all over the place and selecting 5th when slowing down for bends etc. Code came up as MAF ,so replaced that and performed full re-set. Now no longer dies and runs 80% better than before but gear change still seriously clunky and all over the place (box re-set more than once) car has been with independent specialist all day, full diagnostics on everything all values coming back 100% fine. Technician could only advise must be mechanical, torque converter or alike? But unsure. Any help appreciated before I get the gearbox stripped or probably just source a new one.

 

[sonic]

How long ago was the auto gearbox oil changed?

 

[jungledave45]

How long ago was the auto gearbox oil changed?

25k full oil and filter change

 

[00slk]

Does the clunky changes only happen until the car is at running temperature?

 

[jungledave45]

Does the clunky changes only happen until the car is at running temperature?

I would say yes, develops after around 5 mins normal driving from cold.

 

[00slk]

I had a similar issue with my eclass 320. Turned out to be the torque converter locking up. I changed the TC and did around 900 miles and the same problem developed. Possibly the used TC was on the way out?
However I kept driving it and if gradually got worse and changes were very snatchy and the gears would start to slip under heavier acceleration. A couple of days ago I fitted another replacement Transmission and TC and it changing lovely now.

 

[jungledave45]

So how will I determine what TC I need to purchase?