Complete master overhaul kit for the Mercedes 722.6 (W5A580) 5-speed automatic: frictions, steels, and a full gasket and seal set to rebuild the unit in one box.
The same five-speed automatic sits behind engines in a Mercedes E-Class, a Jeep Grand Cherokee, a Chrysler 300 and a Dodge Sprinter. Mercedes calls it the 722.6; Chrysler calls it the NAG1, and the case is stamped W5A580 or one of its sister codes. This kit, reference T14100B, combines the T14102A overhaul gasket and seal set, the T141080B friction plate set and the T141081A steel plate set in one box, listed for the 722.621 through 722.649 build range. It is the kit to buy when a NAG1 or 722.6 is slipping, flaring or burning fluid and is coming out for a full rebuild.
NAG stands for new automatic gearbox in German, and the 1 marks the first version. Inside, three planetary gearsets are controlled by three multi-disc clutches and three multi-disc brakes, and the converter uses a multi-disc lockup clutch rather than a single lining. The unit changes gears by overlap control, handing torque from one pack to the next, so worn frictions or a leaking piston seal show up as flare or a soft shift during that handoff. The T141080B frictions and T141081A steels replace the clutch surfaces, and the T14102A set replaces the gaskets, O-rings and piston seals that hold apply pressure.
Transmission Digest's TASC Force write-up on this unit shows how much of the flare complaint actually lives in the valve body: a worn working pressure regulator valve bore keeps line pressure from rising with load, and worn overlap sleeves in the same circuit do the same thing. On units built in 1999 and earlier, Sonnax also documents a regulating pressure control valve spring that breaks in the middle, with the halves screwing together and changing line pressure, giving delayed engagement and 2-3, 3-4 and 4-5 flare. None of those are fixed by new clutches. Check the fluid first: clean fluid with flare means the valve body comes before the clutches, while burnt fluid full of material means the packs are done. The 722.6 common problems guide lays out the full diagnosis, and the ML problems guide covers the SUV applications.
The kit is listed for 722.6 build codes 722.621 through 722.649 and for the Chrysler, Dodge and Jeep NAG1 W5A580. In the U.S., NAG1 units were also built as the W5A380, W5A330 and W5J400; the last three digits are the maximum input torque in newton meters, and the J400 marks a Jeep unit. Those versions differ in internal parts, so confirm your tag reads W5A580 or a 722.6 build code inside the listed range. A pin stamp on the driver side means a German-built unit, while a bar code tag alone means a Chrysler-built unit. If your tag is unreadable, send the year, model and VIN and we will match it. Other parts for this family are on the 722 transmission parts page.
Check every drum, bushing and the pump for scoring before reassembly; if the input drum is worn, replace it with the 722.6 input drum rather than putting new frictions against a damaged surface. Pre-soak the frictions, set each pack clearance with a dial indicator, and if the valve body bores tested worn, address them now or add a 722.6 shift kit while the unit is apart. Fluid matters on this transmission: per Transmission Digest, Sprinter, Crossfire and Mercedes units need the Mercedes-specified fluid because of calibration, while other Chrysler applications use ATF+4. The filter is not listed in this kit. Flush the cooler before refilling, using the 722.6 drain and flush kit if you have it, then clear adaptations and road test.
| Fits | Mercedes 722.6 (W5A580) 5-speed, build range 722.621-722.649; Chrysler/Dodge/Jeep NAG1 WA580 |
| Part number | T14100B (T14102A gasket/seal + T141080B frictions + T141081A steels) |
| Includes | Overhaul gasket and seal kit, friction clutch plates, steel plates |
| Condition | New |
| Shipping weight | 14.77 lb |
| Ships | From the USA |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
It is listed for the NAG1 W5A580 and the Mercedes 722.6 build range 722.621 to 722.649. NAG1 units tagged W5A380, W5A330 or W5J400 are rated for different torque and are not confirmed by the listing, so check your tag or send us the VIN.
The listing describes T14100B as the T14102A overhaul gasket and seal set, the T141080B friction plate set and the T141081A steel plate set combined.
Mercedes, Sprinter and Crossfire units take the Mercedes-specified 722.6 fluid. Per Transmission Digest, the other Chrysler NAG1 applications use ATF+4. Use what your vehicle's service information calls for.
A pin stamp on the driver side, alone or with a bar code tag, means it was built in Germany. A bar code tag alone means Chrysler built it. The build code on that tag is what you match to this kit.
Yes. Worn working pressure regulator valve bores and overlap sleeves cause 2-3 and 4-5 flare on this unit, and on 1999 and earlier units a broken regulating pressure spring causes delayed engagement and flare. Check fluid condition before deciding on a rebuild.
