Thank you for the well written, thoughtful posting, Jay. I'll be following this thread, as I am sure many others will be commenting.
I hope this doesn't turn into a namecalling, pissing contest, and this topic can be discussed in a civil manner. I can see your points, and I too find it hard to believe VI would have been developed if it were a serious problem in backwards compatibility. I realize MB selected III as their fluid choice at the time of manufacture, but if VI posed any danger, I'd think they(MB) would warn folks somehow.
What is this "idle shudder" you mention?
Can you describe this shudder in detail?
Does it feel like the transmission is surging forward when in drive at idle with your foot on the brake?
Does it occur under all running conditions, drive train cold, hot, warm, uphill, flat, downhill?
Can anyone elaborate on this in terms of the mechanics? What exactly is happening to cause this?
Is this a symptom of eminent failure of the transmission?
Will it leave me stranded on the side of the road?
I am thinking I may be mistaking this transmission shudder for an engine miss in my 94 E320
K miles. My symptoms have been getting progressively worse over the last 1000 miles. The 1st few times I felt this "miss" it felt more like the tranny was trying to drop a gear from 2nd to 1st, at idle, foot on the brake, and the vehicle surged. Now it's become more frequent and more of a miss than a surging effect. It may miss 3-6 times intermittently in a 60 second stop at a light, up from 1-2 times per minute, 900 miles ago.
I am about to change tranny filter/gasket/fluid, but I have not yet determined which fluid to use.
I think Beto65 brought this topic up a few weeks ago, and it got ugly in here. If using VI buys me a few miles before I replace the tranny, I'm in!
The PO of this vehicle advised me that the tranny requires service every 25-30K miles, as he was told this as a MB tech. He told me to change it ASAP, since he didn't know when it was last changed. He guessed at 75K.
BTW, I do not have the telltale symptom of slow reverse engagement, and the only possible tranny quirk I'm experiencing has been hard(pronounced) shifting between gears when cold. Once it warms it's what I'd call "normal", and under WOT it's perfect.