722.9 Clutch Drum, used and ready to install. Fits the 722.9. Ships fast from the USA.
This is a used, original-equipment clutch drum assembly with its apply piston for the Mercedes-Benz 722.9, the seven-speed automatic sold as 7G-Tronic. The drum carries Mercedes part number 221 272 13 31. It is meant for the rebuilder or owner who already has a 722.9 apart and found a drum that is cracked, has a damaged piston, a worn bushing or scored sealing ring lands, or for a car that slips or drops into neutral on one specific shift that has been traced to a single clutch pack. A factory drum in good used condition is often the most practical fix for a 7G-Tronic, because new drums are expensive and slow to get.
The 722.9 builds seven forward speeds and two reverse gears from four planetary gearsets, four multi-disc brakes (B1, B2, B3 and BR) and three multi-disc clutches (K1, K2 and K3). It uses no bands and no one-way sprags, so every shift is a hand-off between two hydraulically applied packs, timed by the control unit. Each clutch lives inside a rotating drum. The drum holds the steel and friction plates, houses the piston that clamps them, and feeds apply oil to that piston through sealing rings on the shaft it rides on. If the drum leaks oil past a cracked wall, a failed molded piston seal or worn ring lands, its clutch cannot clamp hard enough and the control unit sees slip on every shift that clutch takes part in.
A burnt clutch in a 722.9 is very often a symptom, not the cause. Gears magazine says most 722.9 failures it sees begin with cut, missing or hardened O-rings on the solenoid tips, which under-feed a clutch until it burns. Mercedes-Benz diagnostic bulletin LI27.00-P-051451 also requires reading the control unit's log and EEPROM data before any adaptation reset, because a reset erases that history. So scan the car, save the data, then check fluid level and condition. Once the unit is apart, air-check each clutch circuit: a quick, firm apply with no hissing means the piston and drum are sealing. Replace the drum when you find cracks, a damaged piston, a spun bushing or grooved ring lands. Our 722.6 common problems guide covers the regulator bore wear that also burns clutches in the older five-speed, and Gears recommends the same vacuum checks on the 722.9 valve body.
The listing identifies this drum by transmission, the 722.9, and by its Mercedes number, 221 272 13 31. It does not name a single model year. The 722.9 went into production in 2003, was built in several torque versions and was later updated as 7G-Tronic Plus, and Mercedes revised the K1 drum and stator support on early units. Match the part number, the spline count and the piston style to the drum you removed before installing, or send us your year and VIN and we will check it. A year-specific version is listed as the 722.9 clutch drum for 2004, and every other 7G-Tronic part we carry is in the 722.6 and 722.9 collection.
| Fits | 722.9 |
| Part type | Clutch Drum |
| Condition | Used |
| 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.
The listing identifies it as a 722.9 clutch drum with piston, Mercedes number 221 272 13 31, without naming K1, K2 or K3. Compare the number, splines and piston to the drum you removed, or send us your year and VIN and we will confirm before you order.
It is a used original Mercedes-Benz part in good condition with normal wear. Inspect the bushing and ring lands and install new seals and sealing rings before it goes back into service.
That symptom is commonly linked to a failed molded piston, most often in the K1 drum. A drum with a good piston fixes it, but also check the solenoid O-rings, because a leaking solenoid can burn the new pack too.
Plan on new piston seals and sealing rings, new frictions for that pack, a filter and fresh fluid. A 722.9 overhaul or master rebuild kit covers those soft parts.
Use the MB-approved fluid your transmission was filled with: 236.14 on most earlier 722.9 units and 236.15 on 7-speeds built from 2010 on. Do not mix specifications.
Yes. Reset and relearn the transmission adaptations with a scan tool that supports the 722.9 control unit, then road test with the fluid at operating temperature.
