Mercedes 7G-DCT dual-clutch (724.0): problems, costs and what to check

Smooth when serviced, but early cars judder and mechatronic or clutch repairs are costly. Buy on oil history and a cold test drive.

Updated 26 October 2026

At a glance

What it is: Mercedes' 7-speed wet dual-clutch, type 724.0. It fits the A-Class W176, B-Class W246, CLA C117 and GLA X156 (2011-2019) with the M270, OM651 and 1.5 K9K engines; see the M270 petrol and OM651 diesel guides.
Main faults: jerky low-speed shifts, clutch wear, and mechatronic or auxiliary oil pump faults.
Reliability: 2/5, because clutch and mechatronic repairs are common and expensive.
DIY: 2/5, because fault reading and adaptation need XENTRY or a suitable scanner, and the oil level is critical.
Prefer: a car with fluid and filter invoices, a software update on record, and a smooth cold test drive.
Avoid: a car that judders when cold, shows a transmission warning, or has no gearbox service history.

Known issues

Issue	Affects	Typical km	Repair cost
Jerky low-speed shifts and judder	All cars; worst before 2014	Any, often from cold	No confirmed price
Clutch pack wear	All cars; more with stop-go and trailer use	Over 200,000 km (Kolesa.ru)	1,600 to 2,600 EUR (Germany, year not stated; Gebrauchtwagenberater)
Gearbox control unit (mechatronic) faults	All cars; worst before 2014	About 200,000 km (Auto.ru)	No confirmed price
Auxiliary oil pump failure	All cars	Not stated	No confirmed price

Before you buy

Clutch check (needs a scanner). Start cold, creep and pull away in 1st and 2nd, and hold on a hill. Judder, slip, or a vibration at a standstill with the brake on points to worn clutch plates. Read the clutch touch points (Kisspoint) in XENTRY, Mercedes' diagnostic software; K1 odd gears, K2 even. A value past the threshold means a new clutch.
Mechatronic scan (needs a scanner). Read all transmission codes, not just engine codes. A clean scan does not prove health: one 2014 CLA had no codes but still shook and once dropped into neutral. A stored code, a red warning or a limp-home episode means a control unit job.
Auxiliary oil pump warning. Ask whether a "Transmission malfunction" message appeared and cleared after gentle driving. A message that stays, or a "stop vehicle" warning, points to the auxiliary pump or control unit. Scan for codes.
Cold and warm road test. Drive in stop-go traffic and lift off in 1st and 2nd. Jerking that stays when warm, or shifts that hang under load, points to software, adaptation or clutch wear. Ask for the last software update.
Oil and filter records. Ask for invoices for the fluid and both filters, and for the adaptation reset after the last oil change. No record, black oil or metal fuzz on the drain plug means walk away or budget for a service. Dirty oil damages the control unit.

Models with this gearbox

Brand	Model	Generation	Production years	Power	Engine codes	ADAC versions
Mercedes-Benz	A-Klasse	176	2012–2015	90–211 PS (66–155 kW)	270910, 270920, 651901, 651930, K9K	76
Mercedes-Benz	A-Klasse	176 facelift	2015–2018	90–218 PS (66–160 kW)	270910, 270920, 651930, K9K	94
Mercedes-Benz	A-Klasse	177	2018–2020	116 PS (85 kW)	K9K	22
Mercedes-Benz	B-Klasse	246	2011–2014	90–211 PS (66–155 kW)	270910, 270920, 651901, 651930, K9K	17
Mercedes-Benz	B-Klasse	246/242 facelift	2014–2018	90–211 PS (66–155 kW)	270910, 270920, 651930, K9K	184
Mercedes-Benz	CLA	117	2013–2016	109–218 PS (80–160 kW)	270910, 270920, 651901, 651930, K9K	107
Mercedes-Benz	CLA	117 facelift	2016–2019	109–218 PS (80–160 kW)	270910, 270920, 651930, K9K	191
Mercedes-Benz	CLA	118	2019–2020	116 PS (85 kW)	K9K	10
Mercedes-Benz	Citan	420	2021–2026	95–116 PS (70–85 kW)	K9K U8	18
Mercedes-Benz	GLA	156	2014–2017	109–211 PS (80–155 kW)	270910, 270920, 651930, K9K	83
Mercedes-Benz	GLA	156 facelift	2017–2020	109–211 PS (80–155 kW)	270910, 270920, 651930, K9K	130
Mercedes-Benz	GLA	247	2020–2023	163 PS (120 kW)	270910	5
Mercedes-Benz	T-Klasse	420	2022–2026	95–116 PS (70–85 kW)	K9K U8	22
Nissan	Qashqai	J11 facelift	2019–2020	115 PS (85 kW)	K9K	11
Renault	Captur	II	2020	115 PS (85 kW)	K9K U8	2
Renault	Kadjar	1. Generation facelift	2019–2022	115 PS (85 kW)	K9K U8	10
Renault	Kangoo	III	since 2024	115 PS (85 kW)	K9K U8	2
Renault	Mégane	IV	2016–2020	110–115 PS (81–85 kW)	K9K G6, K9K U8	24
Renault	Mégane	IV facelift	2020–2024	115 PS (85 kW)	K9K U8	16

In detail

Jerky low-speed shifts and judder

Symptoms. The car shudders or jerks when creeping, pulling away, or lifting off in 1st and 2nd. Shifts can hang under load, and some cars vibrate at a standstill with a gear engaged and the brake held. It is worst when cold and in stop-go traffic.

Cause. A wet dual-clutch has no torque converter, so it can feel jerky at very low speed. Early software and clutch adaptation made it worse. Russian reports single out pre-2014 cars.

Which cars. All cars, worst before 2014; a 2016 B200 and a 2014 CLA still appear in owner reports.

Fix. A Mercedes software update fixed most cases in German reports. A shift-fork or clutch adaptation reset with XENTRY helps; AutomotiveTechInfo says the oil must be at least 35 °C and the brake held.

Sources: Gebrauchtwagenberater, A-Klasse W176 Probleme und Kaufberatung, kfz-dietrich, Mercedes Diagnose A-Klasse W176, Auto.ru on reliable robot gearboxes, MBClub UK, Jerky Transmission

Clutch pack wear

Symptoms. Judder when pulling away, a vibration at a standstill with a gear selected and the brake on, and slip when manoeuvring or on a hill. Traffic, short trips and towing make it worse.

Cause. The wet clutch plates wear like a manual clutch. A faulty control unit shortens their life. The clutch pack is not serviceable, and few rebuilds have worked.

Which cars. All, especially cars in traffic or towing. Kolesa.ru puts clutch life at over 200,000 km with a healthy control unit. A 2015 A200 test car was still smooth at 225,000 km, but its oil was black.

Fix. A new clutch pack and calibration. Read the Kisspoint values in XENTRY: K1 covers odd gears, K2 even gears. A value past the threshold means the plates are worn. Reset and relearn the adaptation after the job.

Cost. Gebrauchtwagenberater puts a double-clutch replacement and calibration at 1,600 to 2,600 EUR (Germany, year not stated).

Sources: kfz-dietrich, Mercedes Diagnose A-Klasse W176, Gebrauchtwagenberater, A-Klasse W176 Probleme und Kaufberatung, Auto.ru on reliable robot gearboxes, Kolesa.ru on the W176 at high mileage

Gearbox control unit (mechatronic) faults

Symptoms. Rough or delayed shifts, a "Transmission malfunction" warning, limp mode or loss of drive. A red warning can drop the car into neutral at a standstill. A scan may show no transmission codes even when the car jerks.

Cause. Sensors and solenoids in the control unit, called the mechatronic, fail. Dirty oil makes it worse. Early units, built before 2014, are the most affected.

Which cars. All, early cars most. Auto.ru puts average life before a serious repair at about 200,000 km.

Fix. Try a software update first. If that fails, repair or replace the control unit. Change the oil and both filters. Read the "MB Hardware Object Number" in XENTRY before ordering, because the parts list can be wrong.

Sources: Auto.ru on reliable robot gearboxes, Kolesa.ru on the W176 at high mileage, AutomotiveTechInfo, 7G-DCT care and maintenance

Auxiliary oil pump failure

Symptoms. A "Transmission malfunction" message that does not clear after gentle driving, with the gearbox overheating. A "Transmission malfunction, stop vehicle" warning means stop and tow.

Cause. The small electric oil pump inside the control unit can fail.

Which cars. All.

Fix. Replace the auxiliary oil pump. It is available separately from the control unit.

Sources: AutomotiveTechInfo, 7G-DCT care and maintenance, Auto.ru on reliable robot gearboxes

Recalls

No recall for this gearbox was found in the sources read. AMG versions are not covered here. Check open campaigns by VIN with a Mercedes dealer before you buy.

Maintenance

Gear oil. Use oil to MB 236.21. AutomotiveTechInfo gives 60,000 or six years for a 2014 CLA (unit not stated); MBClub owners quote 62,000 miles or five years; AUTO BILD (2021) gives 100,000 km or five years. Follow the service book.
Oil change. About 4 litres go in, and the final top-up often takes more than 1 litre. Level is critical: AutomotiveTechInfo says 50 ml too much or too little can change shift quality. Change both filters, pan and top cartridge.
Adaptation. Reset and relearn the clutch and shift adaptation after an oil change, a clutch job or a control unit job. This needs XENTRY; AutomotiveTechInfo says the oil must be at least 35 °C.
Cost. A workshop oil change is about 500 EUR (Germany, 2021, AUTO BILD); DIY is about half with a Meyle kit and just over an hour. Gebrauchtwagenberater puts a Tim-Eckart flush at 400 to 650 EUR (year not stated).