Mercedes-Benz W211 7G-Tronic jerks or shifts hard
Why does the W211 7G-Tronic automatic jerk or shift hard when cold?
A slight jerk when cold is normal, but a strong one often points to old or wrong oil, or the wrong oil level. If the fault is mechanical, the symptom returns. Have the fault memory read with a Star tester.
How often is the W211 7G-Tronic oil changed, and which oil suits it?
The transmission should be serviced about every 60,000 km. An ATF of the MB 236.14 class is recommended for the 722.9 transmission. The wrong oil can cause major damage, and additives are best not used.
Is an oil change alone enough for 7G-Tronic jerking?
In a drain-and-refill, most of the old oil stays in the transmission, so a flush change may help more. It takes know-how and a Star, and the wrong oil level can ruin how it works. The variation often settles only after a few days of driving.
What should I do if there are iron particles in the 7G-Tronic oil?
The transmission may then shift poorly and jerk, and the particles point to internal wear in the transmission. Have a workshop investigate before you continue driving.