Wompusdude

My E55 was having some hard TC lock-up when the trans was cold. Would go away after about 15 mins of driving. I looked into it and saw that Sonnax had a damper kit for the valve body. So I bought that along with their Master Overlap Control Valve kit, which is essentially new valve sleeves for the gear changes (3 of them). Decided to do those while I was down there as it seems to be a common maintenance piece.

While the valve body was out I split and the halves and cleaned out some gunk. Had a few of the check ***** fall out of the lower half but I put them back in and double checked their proper location, all looked good.

Anyways, got those valves all swapped, new conductor plate and got the valve body back in. Put 4qts of trans fluid back in. Reset adaptations by using the “hold peddle to ground” method. Took it on a test drive and the TC no longer has a harsh lock up Gear change 1-2 is very smooth. But unfortunately the car no longer shift from 2-3. I tried making it shift in manual mode and it eventually stumbles really hard and goes back in to 2nd gear

Obviously going to have to drop the valve body again, but does anyone have any thoughts on what I should be looking for? I’m thinking 1 of 4 things, but just my thoughts.

1. Issue with 2-3 solenoid
2. Issue with 2-3 valve
3. Improper valve body install
4. possible debris in a hydraulic circuit (unlikely though)

nd-photo.nl

I also had shifting issues after replacing the conductor plate and refilling the gearbox. For me it was the adaptation reset which solved the issue. There seem to be 2 methods for this, also see the youtube vid that I posted in the thread I created not too long ago. I was also hesitant if I installed the valve body correctly, so I made some detailed pictures (I was worried about the yellow sliding lever not being in the correct place) which can also be seen in that thread.

https://mbworld.org/forums/w211-amg/...box-drain.html

[edit]
There are 2 reset procedures possible, try them both to be sure

Pmarino

722.6 Valvebody overhaul

Use of scan tool

SICAMG

First thing your low on fluid. It takes more than 4 qt's after valve body job.
Second a check ball may not be in the correct location.
Scan it for codes and see what comes up. If no codes more than likely check the ball in wrong location.
I have built a few of these so that's my best guess for you.
But.....check fluid first before you do anything.

nd-photo.nl

From what I've read here on MBWorld, its crucial to have the right amount of fluid in the 722.6 gearbox (use the special dipstick!)

Wompusdude

I have a feeling that this plastic check ball ought to be in the valve body and not in the drain pan 🤔… just a thought though lol I’ll keep you guys updated

SICAMG

Been there.....done that !!!! There is the issue.
But hey gives you a chance to put more fresh fluid into it !!! Should be nice and red after the second time LOL

Wompusdude

going to grab some more Pentosin ATF 134 and some brake clean to clean out the inside of the valve body again. Get it all installed and reset adaptations. Should have it back together in the next hour or so, I’ll let you know the outcome. Really hoping that was the issue 🤞

tlambert

Good thing you didn’t dump the fluid out of the drain pan huh. Lol

SICAMG

That was it for sure so take your time this time around !!

Wompusdude

Am I using the dip stick wrong?!? I literally just put 2 liters of fluid in the trans and the dipstick is reading almost up to the 80C mark. Fluid is I still ambient temp.

if I’m correct, I’m just suppose to put the dipstick down the tube until it hits the bottom. But doing that gives me weird results.

SICAMG

That's it but I will quickly pop the stick in and out. Always seems to give a better reading.

Wompusdude

Put 3.8L of ATF into the trans, reset adaptations and took it around the blocks a few times. Successfully got up to 4th gear, didn’t have enough speed to get to 5th. Seems the issue is solved!

TC lock-up is still noticeable but definitely better. Hoping it’ll become a little softer as the trans adapts over time.

I’ll be at work for the next 7 hours, I’ll check the fluid level again once I get back.

nd-photo.nl

Also check this older thread, I will probably be doing this the next time I do an ATF flush

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

kevm14

If you go in there again replace the TCC solenoid, too.

Wompusdude

think it’ll help that much?

it’s kinda odd. I’m not sure how smooth the lock up is supposed to be, but sometimes I don’t notice it at all and sometimes it’s got a pretty noticeable lock up.

same with down shifts, every so often a down shift can be a bit clunky. Not jarring, but they’re noticeable