Do the adaptation values need resetting after a repair?

Often yes, and it is part of the job rather than an optional extra. A transmission that has been compensating for a worn solenoid for two years will not shift correctly on the old learn values with new parts fitted.

It shifts fine when cold and badly once warm. What does that mean?

That pattern normally points at something electrical or a solenoid drifting as fluid thins with heat, rather than mechanical wear. It is a better diagnosis than it sounds, because it is usually a repairable part rather than a gearbox.

Is it worth fixing at 190,000 km?

That depends on the rest of the car, and we will do that maths with you honestly. A $1,800 conductor plate on an otherwise good car is usually reasonable. A $6,000 repair on a car with a tired air suspension and a timing chain rattle is usually not, and we will say so.

7G-Tronic shifting hard or flaring: what to check before anyone quotes you a new gearbox

The parts that actually fail

The conductor plate — the solenoid block and control unit mounted on top of the valve body inside the sump — is the most common electronic failure. When one of its solenoids or its internal pressure control drifts, you get flare and harshness on specific shifts rather than everywhere.

The direct shaft and servo bore wear with mileage, which produces delayed engagement and a flare that a fluid service won't cure.

The torque converter's lock-up clutch can shudder, which people feel as a rumble in the last few shifts.

And the simple one: old fluid and a partially blocked strainer. It is genuinely the most common cause on cars that have never had the transmission serviced.

Service interval, because it is not 'lifetime'

The 722.9 wants its fluid, pan gasket and strainer changed at roughly 60,000 km or four years. The cars that arrive needing a conductor plate or a bushing repair overwhelmingly are the ones that never had this done.

How we diagnose it

We read adaptation values and run solenoid and pressure-control tests with a proper Mercedes-capable scan tool, because adaptation values tell us whether the transmission has been compensating for something for months.

We check fluid level at the correct temperature — this transmission is level-checked at a specific temperature range, and checking it cold gives a wrong answer.

We road test with a logged shift trace so we can see exactly which shift misbehaves and at what load.

Only then do we talk about parts. And we will not put a flush machine on a high-mileage unit that has never been serviced — that is how a working transmission stops working.

Indicative cost

Service (pan drop, new gasket and strainer, correct fluid): $500–$950. Conductor plate or solenoid pack: $1,200–$2,600. Direct shaft bushing repair: $1,500–$3,200. Torque converter: $1,200–$2,500.

A transmission replacement quote should be the last number you hear, and only after the above have been tested. If you have one, bring it — we will tell you if it is unnecessary.

Questions owners ask about this

Do the adaptation values need resetting after a repair?: Often yes, and it is part of the job rather than an optional extra. A transmission that has been compensating for a worn solenoid for two years will not shift correctly on the old learn values with new parts fitted.
It shifts fine when cold and badly once warm. What does that mean?: That pattern normally points at something electrical or a solenoid drifting as fluid thins with heat, rather than mechanical wear. It is a better diagnosis than it sounds, because it is usually a repairable part rather than a gearbox.
Is it worth fixing at 190,000 km?: That depends on the rest of the car, and we will do that maths with you honestly. A $1,800 conductor plate on an otherwise good car is usually reasonable. A $6,000 repair on a car with a tired air suspension and a timing chain rattle is usually not, and we will say so.