NRL

I think I'm having the famous TCC Solenoid issue with the 722.6 Transmission.

My symptom is it lurch somewhere between 1800rpm and 2400rpm before it shifts from 1st -> 2nd gear.. in S mode and also before it shifts from 2nd -> 3rd Gear.

It only happens when it's cold or if the car has been sitting. After warming up about 10-15 minutes, it gets better and completely goes away after driving for 10+ miles..

From reading all the threads, it looks like the TCC Solenoid is acting up and needs to be replaced even though there were no codes thrown..

Another solution might be is to do the DAS adaptation learning mode where you have to drive at a specific speed, torque range and it re adapts the lockup clutch.

I did some tests by turning off the lockup clutch at cold start via Xentry/DAS, and the lurch goes away; and it drives perfect..

Wondered if anyone has had the same issue and had it resolved.

ItalianJoe1

Didn't see this before.

I had some, fairly severe, TCC and shifting issues in my car. I dropped the valve body and did a new conductor plate and trans service, and replaced the pistons Sonnax sells with the upgraded ones, one was the TCC apply piston. Between the fresh fluid and the reduced leakage through the VB, it feels like a new trans. I was fairly certain before the service that I was wasting my time and would end up needing a new converter and trans rebuild. I am still amazed at how much better it got for such a minimal investment.

Sonnax 68942-23K and 68942-05K were the two kits I ordered, cheapest deals I could find were vendors on Ebay/

FWIW, I was going to change the solenoids as preventative while I was in there, now I'm glad I didn't, as they are NOT cheap and as it turns out, not a problem. Do clean them very well while you are in there though.

NRL

Thanks for your reply. I will order the Sonnax kits.

I'm planning to work on it over the Holidays.
It's temperature dependent, since when it warmed up after about 4 miles of stop and go, it completely goes away.

I found an Indie that will do the labor for about $350.. pull out the valve body, replace the solenoids, conductor plate.. but I really want to pull it out and see for my self since on the plate, there seems to be a few filter screens below some of the solenoids that may be slightly clogged (Saw a video where they take a magnet and remove the metal fillings off the screen).

So it's either of the following:

The List so far:
TCC solenoids (acts up when cold) (Replace Solenoid)
The Apply Piston Valves (Pressure leaking due to clog or bore wear) (Replace withSonnax Kit)
The conductor plate (screen clog, or temperture sensor flaky on the plate) (Replace Conductor Plate).

ItalianJoe1

From what I see in the shop, the conductor plate should be a wear item that is replaced with normal services, they are almost always an issue, even if they aren't all the issues.

Check your transmission harness plug for fluid transfer also, it may be pushing fluid up your harness and causing weird issues. If the Indy shop you are using is familiar with benz they are probably including it in the service, it's a cheap part and again a common failure point, should be changed whenever the pan is down IMO.

fireman685

Good info. I too am having a similar issue. It lurches hard when cold. The longer it's driven it becomes silky smooth.

biker349

great info. thanks

shadenfroh

Can you elaborate what you mean by lurch? Is it that the car lurches forward too harsh just before the shift takes place? That's the symptom I have.

thtguy

I was getting a shudder between 1500 and 2500 at part throttle in all gears. Full throttle no issues. I replaced the tcc lockup solenoid and fixed issue. Went to Dodge dealer and Paid $40 less than the MB dealer quoted.

ItalianJoe1

Yeah but the dodge solenoids aren't always the same. If it's the same part #, which the TCC probably is, then that's awesome. But the shift solenoids are heavier in the high torque 722.6 than the Chrysler NAG1.

NRL

I got some off-time and spent half a day on swapping out the conductor plate and the tcc solenoid.

The hard part really was jacking up the car safely with jacks and ramps front and back, enough for me to get under safely with enough room to remove the valve body (it wasn't really that heavy after experiencing it once).

The issue completely went away. From cold start, the lurch is gone.

Back to enjoying the Ride..

Luke81Roberts

Anyone know if it’s bad for the car to drive it like this? At school currently and won’t be able to do the job for 4 months unless it’s absolutely essential.