Had slip / shutter between 1400 - 1600 RPM - Dealer said torque converter but that metal bits are now in transmission and that need to be replaced as well - would not do just torque converter - At $8k I am not doing both. Just trying to get a sanity check if this is logical or if I could just do the torque converter.
Thoughts?
2011 E350 118k miles

 

The dealer may not warrant the TC work due to possibility of metallic debris being circulated back thru both TC and transmission, but it depends on the nature of the TC failure I think. ItalianJoe is a member here and I think also an MB tech so you may want to ask him directly.
In general, my experience is not with MB transmissions, but if basic operational principles are similar to other transmissions, the TC spins the pump which provides fluid and pressure to various components, valve body, solenoids, servos etc. Fluid is pulled from the pan thru a filter, circulated, then back to the pan. Very simplified description, as there are a number of sensors/controls in there as well.
If you consider a metallic failure somewhere, then metal debris in fine silt form and often larger pieces are pulled and pushed through the entire system in the fluid until they are trapped by something like the filter, a solenoid screen, or become embedded into clutch surfaces and behind seals. They can also clog passages within the valve body. Somehow the internals (and cooler) need to be cleaned or replaced, depending on what happened and what's floating around in there. I do know that when there is a transmission failure or replacement, TC replacement is usually mandated. Often the cooler needs to be replaced unless its a straight pass-thru design that can be completely flushed. Many thermostatic transmission fluid coolers can't be properly flushed so they get replaced.
In this case the TC developed a failure (slip) but I don't know the severity of the failure and thus how much debris may or may not be present in the transmission. I also don't know if the MB TC is uniquely different from what I am more familiar with on domestic vehicles so there may be more factors in play. So on the one hand, you could replace it all to be sure. On the other hand, if you decided to roll the dice then I would think a transmission pan drop and valve body removal, filter replacement, and check or replace solenoids in addition to complete fluid exchange may be needed to try to get as much debris as possible out of the system.
These are all just my thoughts - certainly you can also perhaps get a second opinion/quote as well, and you may also find out more info as you look into it further.

 

Thanks - I guess if I know I will likely not spend for the full transmission and TC - I could simply do a pan drop filter replace and new fluid - see how it goes from there.

Open to others experience with similar issues - been searching a bunch - again shudder rpm dip around 1400 - 1600 rpm

Also dealer said 1150 for TC not installed - seems way high based on quick search

 

Hello,

Browsing through the forum I found your issue you had way back with debating on what to do about your transmission issue below, I have similar, please let me know how you solved your issue.

Thanks so much.

 

I know it’s an old thread but I was wondering if changing the fluid and filter worked. Mine has a shudder between 20-25 mph.

 

A fluid change is a great start. Fluid properties like anti foaming do not last forever and that has been attributed to hard shifting. The theory is that the micro bubbles make the fluid somewhat compressible and when the bubbles collapse it can cause hard shifting that you can feel in the car chassis.

 

I went ahead and had it changed. It’s better but still there