722.9 Sun Shell, remanufactured and ready to install. Fits the 722.9. Ships fast from the USA.
This 722.9 part is listed in our catalog as a sun shell, and it is specifically the front planet assembly from a Mercedes-Benz 7G-Tronic, the version with 30 lugs and an aluminum housing. It is a factory Mercedes-Benz part that has been cleaned and inspected. Rebuilders reach for it when a 722.9 comes apart with a chewed-up front gearset, pitted pinions or a cracked housing, and owners of C-, E-, S-Class, ML, GL or Sprinter models with the seven-speed find it when a road-speed whine or a missing gear has been traced to the gear train.
The 722.9 gets seven forward ratios and two reverse ratios from four planetary gearsets, two of them combined into a compound Ravigneaux set, and seven shift elements: four brakes and three clutches. There are no bands. Each gear is produced by the control unit applying a different combination of those elements to lock or drive the sun gears, ring gears and carriers. The front planet assembly sits at the input end of that gear train, so it carries engine torque in most ratios and its pinions spin fast in the upper gears. The lugs on the housing engage the mating clutch plates, which is why the lug count and housing material have to match the unit you are repairing.
Rule out the common 7G-Tronic faults first. ATRA's Gears Magazine reports that most 722.9 failures it sees start with deteriorated solenoid tip O-rings that starve a clutch until it burns, and that early units suffered bearing failures between the K1 drum and the stator support. A whine on early units can also come from the pump bushing against the converter hub. Mercedes' own diagnostic bulletin for shift complaints tells technicians to read out and save the control unit data before replacing anything. Then drop the pan: steel debris points to the gear train, lining alone points to a slipping clutch. With the unit apart, spin every pinion, measure carrier end play and inspect the splines and lugs. Our 722.9 rebuild cost guide covers what else usually gets replaced once the case is open.
This assembly fits the Mercedes-Benz 722.9 with a 30-lug, aluminum front planet housing. The 722.9 was built for many years in several torque ratings and later updated as 7G-Tronic Plus, and not every version uses this exact housing. Count the lugs on the part you removed, confirm the housing is aluminum, and compare the tooth and spline count before ordering, or send us your year, model and VIN and we will check it. If you need a different gearset from the same transmission, see the 722.9 planetary, and browse the full 722 transmission parts collection for drums, pumps and valve bodies.
Rebuilding an early 722.9 and still chasing hydraulic shift problems? The 722.6 common problems guide explains the regulator bore wear that Gears Magazine also flags in the 722.9 valve body.
| Fits | 722.9 |
| Part type | Sun Shell |
| Condition | Remanufactured |
| Brand | OEM |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
It is the 722.9 front planet assembly with a 30-lug aluminum housing. It is listed under sun shell in our catalog, but the part you receive is the front planet assembly described on this page.
No. It is a factory Mercedes-Benz part that has been cleaned and inspected, which is how most 722.9 hard parts are supplied outside a dealer.
Possibly. Housing designs changed across production, so count the lugs and confirm the aluminum housing on the part you removed, or send us your year, model and VIN to check.
The thrust washers and bearings on either side, the filter, and the solenoid O-rings if the valve body is out. If the clutches are burnt, do a full overhaul with a master rebuild kit.
Later units are filled with ATF meeting MB 236.15 and earlier units with MB 236.14. Use the specification for your build and do not mix the two.
