Doss

Yes, I have searched here and on other forums. Issues started about 800 miles ago. I will list what I observed and what has been done. The car is a 2003 E55 with 114k miles, no mods, very well maintained, and it's not driven hard. Transmission is not engaging except for a few brief seconds after TCU fault clearing. Starting from 800 miles ago...

1. On a 450 mile round trip, the car started droning heavily at 1800 RPMs. Never happened before. Continued droning throughout the trip.
2. Got home, droning problem was intermittent, but I swapped to Black Series engine mounts and OEM trans mount. Factory mounts were dead. Dropped trans pan, swapped filter, and refilled with Pentosin 134. Fluid was medium brown and clear. Checked pilot bushing and it was dry. Droning problem reduced significantly but persisted. Intermittent harsh shifts and shuddering under heavy acceleration started.
3. Cruising at 40 mph, car suddenly just free rev'd (like it was in neutral). I managed to coast to a stop. Turned off car, restarted, and problem (no gear engagement) was gone. Droning and shuddering still intermittent.
4. Drained fluid with Mightyvac and refilled with Shell 134. Drove round trip 200 miles. Intermittent, mild droning continued.
5. Car started shifting hard when cold. Problem with car revving but not staying in gear reappeared. Limped car home 1 mile using park, turn off, and turn on method. 715 and 730 codes present.
6. Drained transmission. Replaced conductor plate, pilot bushing, and filter. Solenoids looked old and plastic around connectors were broken on some. Didn't have spares so I didn't replace. Someone else has been in the trans at some point bc I have blue top solenoids. Added an external transmission cooler and bypassed the radiator. Filled with Shell 134.
7. After #6, transmission was in Comfort mode (as usual) and would not leave second gear but otherwise fine(?). Car makes so much torque you can actually daily in just 2nd.
8. Flushed with Mightyvac and Shell 134 again. No change in behavior. Got iCarsoft v3.0. Reset TCU. All gears available now and buttery smooth shifting now returned. Drove about 100 miles and car would shudder moderately under heavy acceleration from a stop.Droning was intermittent but very low in intensity.
9. Transmission seemed to get better with every flush and refill which I was doing every couple of trips (each trip about 10 miles). I put about 12 quarts through the trans. Then, the "gear engaging but no drive" returned with a vengeance. Started on the interstate on a 10 mile round trip. Drove 3 miles and problem started. 2 more miles and I parked for dinner. Drove home and made it 4 miles without issue and then a lot of problems. Stop, turn off, turn on, and drive. Car would attempt to shift gears and disengage. Each time the car went shorter and shorter distances. I could no longer change bt Manual, Comfort, and Sport at this time... Stuck in C. Finally, 6 blocks from home, even this procedure stopped working. I walked home, got the iCarsoft, and cleared the TCU 3 times to get home. Regained trans mode selection but any gear change would trigger the drive disengage.

I'm trying to determine next steps. TCU is not showing any faults. I'm not above going to a shop, but I also like doing things myself. I am thinking about replacing the solenoids. I'll check their pressures first (they checked fine every time previously). I was going to do the Sonnax kit too. Finally, a torque converter replacement if necessary (rear main seal is leaking anyways).

Coincidentally, the auxiliary battery appears to be toast. Need to swap it too.

Any thoughts on what to do next are appreciated.

Yuille36

Did you check the transmission electrical umbilical cable that puts into the transmission, often times transmission fluid leaks into the cable wiring causing issues.

nd-photo.nl

Did you replace the O-rings of all solenoids? I serviced my gearbox last year and I totally forgot about them. Mine has 194k kms on the clock and the O-rings were hardened and need to be replaced. My shifts are ok, but sometimes a little harsh.

Also try this:

Doss

Would the cord have any fluid if the pilot bushing was completely dry with no residue? I'll definitely look it over. When I swap the solenoids, that should also fix the O-ring issue if there is one.

Thanks for the feedback.

For those that are curious about parts quality, I usually only replace with OEM or better. I have gone through most of the car to to restore it to showroom condition.

bbirdwell

Possibly the TCC solenoid. Aka the lockout solenoid. Try a search on it and see what info you can find.

nd-photo.nl

https://mbworld.org/forums/c32-amg-c...em-solved.html

SICAMG

I would say torque converter was your main problem but now transmission has followed suit. More than likely will have to come out and gone through.
Evert time you changed the fluid it would help with torque converter lock up and I do not believe a solenoid would be helped by new fluid plus you had no codes if there was an electrical issue.

Doss

Updating to keep this moving: I have ordered the two Sonnax kits and will install this weekend. I am ordering TCC solenoid and the 3 other solenoids (not the replacing blue tops). Hopefully these will be installed this weekend as well.

I still think torque converter may be an issue, but outside of shuddering, I haven't seen anything that points to it (well, a slipping code but that could be caused by the sleeves).

Doss

Just keeping this thread updated:

I just swapped in the Sonnax kit for all three sleeves, added a new TCC solenoid, and replaced the 3 shift solenoids. I left the blue tops in place. I also disassembled the valve body and thoroughly cleaned it.

This resulted in a reverse and then drive but then no movement. Total time mobile was about 30 seconds.

At this point, I'm pretty sure it needs to see a transmission shop. I suspect the converter and I don't have the room to drop the transmission and swap the converter.

If it is the converter, any recommendations on a new one? I don't need a high performance converter as this car will stay stock and won't see any racing. OEM is probably fine, but I figure with the 722.6 in so many cars, there might be a better alternative for the same kind of money.

SICAMG

What did the fluid look like and was there any debree was in the pan ?

Doss

Clean red fluid, nothing on the magnet, and no codes.

I forgot to mention, the transmission started making a whining noise as this got worse. It did this intermittently and sometimes loudly and sometimes very quietly. It could be the front pump but it's never long enough for me to troubleshoot.

Besides taking off the front hose and checking it for flow, is there any other way to check the pump?

SICAMG

Your fluid is clean because you flushed it so many times so does not give a real indication of fluid diagnosis but you said it was brown before.
If the trans stops moving after all you have done.....it has to come out.
Unfortunately since you cant do it it will need to go to a shop to do.
Or have an indie pull it and try and fix yourself.

Doss

I would say on the first change it was dark but not so bad I would be concerned. There was a light sludge of ultrafine material on the magnet, but the pan was relatively clean. It really just looked like it had not been changed in a while. My guess is whenever the previous owner (I am the 2nd owner) put in blue tops (which I don't have record of despite the car having 17 pages of documentation).

I'm going to swap the filter again and check the pressure going to the front cooler. Then, it goes to a shop.

cannawhat

Any update on this? I feel a shudder on mine while shifting. I am wondering if this is just a torque converter?

Doss

Honestly, my car has sat since this time (I start it to keep the battery topped off and roll it a few feet in either direction to avoid flat spotting wheels). I have other cars I can drive so it's really just figuring out if I want a high stall and scheduling time to fix.

I am 95% sure it is the converter. The oil pump (transmission) may be bad too but I'm not certain on that one. I'll probably know within the month; but, if you're feeling juttering, hearing whining while driving, or have it reving higher than normal, it's probably the converter or the clutches within. You'll want to take a check on your radiator coolant too. I suspect coolant may have mixed with transmission oil bc my coolant level dropped at the same time I experienced the issues. I didn't see evidence in the transmission fluid change. I swapped to an external cooler but I believe it was too late. Hope this helps you.

cannawhat

Thanks for the update. am curious what you find. Mine is a 2006 and that is not supposed to suffer from the coolant mixing in with transmission fluid.