How to Change Mercedes 9G-Tronic Transmission Fluid (722.9 / 725.0)

📋 Quick Facts

The 725.0 9G-Tronic is in nearly every rear-wheel-drive Mercedes since 2014 (C, E, S, GLC, GLE, GLS, G-Class). Mercedes calls it lifetime. It is not. The valve body solenoids are sensitive to ATF degradation - 60,000 miles is the practical service interval. Use only MB 236.17 spec fluid (Shell ATF 134 FE, also sold by Fuchs and Total under MB approval).

🛠 What You'll Need

• Shell ATF 134 FE (MB 236.17), 9 quarts (Shell ATF 134 FE on Amazon)
• Mercedes 725.0 transmission filter and pan kit, P/N A 725 270 03 00 (Mercedes 725 filter kit on Amazon)
• New drain plug and crush washer, P/N A 007 990 06 51 (MB crush washers on Amazon)
• 8mm hex and Torx E10/E12 sockets (hex/Torx set on Amazon)
• Mercedes-capable scanner with live ATF temp PID, e.g., Autel MS906, Foxwell NT530 MB (Foxwell NT530 MB on Amazon)
• Fluid transfer pump (fluid transfer pump on Amazon)
• Torque wrench 5-80 ft-lb (torque wrench on Amazon)

✅ Before You Start - Checklist

• Park on level, solid ground (no slopes, no soft dirt)
• Vehicle and fluids at the correct temperature for the procedure
• All tools, parts, and scanner on hand BEFORE you begin
• Owner's manual and OEM service procedure nearby for torque specs
• Safety: gloves, eye protection, wheel chocks, jack stands rated for vehicle weight

📝 Step-by-Step Instructions

1. Drive 10 minutes to warm the transmission to about 95 FPark on a level lift. The 725.0 level check is extremely tilt-sensitive.
2. Remove the underbody plastic trayMultiple 8mm bolts and plastic clips. Set aside.
3. Locate the drain plug (8mm hex) on the side of the casePlace pan, remove drain plug. Expect 5-5.5 quarts.
4. Remove the pan (Torx E10) and the filterCatch additional fluid. The filter snaps into the valve body - pull straight down.
5. Install new filter and pan gasketUse the complete kit, P/N A 725 270 03 00. The filter O-ring should be lubricated with fresh ATF.
6. Torque pan bolts in cross patternTo 7 ft-lb (10 Nm). Aluminum pan strips at 12+ ft-lb.
7. Install new drain plug with new crush washerTorque to 15 ft-lb (20 Nm).
8. Remove the fill plug on the side of the caseThis is your level overflow plug. Set aside.
9. Pump 7 quarts of Shell ATF 134 FE through the fill portUse the transfer pump. Initial fill is about 80% of total.
10. Start engine, cycle gear selectorFoot on brake. Move P-R-N-D-S-M-N-R-P, holding each for 5 seconds.
11. Monitor ATF temperature via scannerWait until temp reads 104-122 F (40-50 C). MB specifies this exact window.
12. With engine running at correct temp, crack the fill plugA small stream means correct level. Drips only = add 200ml. Heavy stream = overfull.
13. Top up in 200ml increments through fill port until correct overflow streamHave a 9th quart of ATF 134 FE on hand - 725.0 service usually takes 7-9 quarts.
14. Reinstall fill plug with new crush washer, torque to 15 ft-lb (20 Nm)Wipe area clean.
15. Run transmission adaptation via Mercedes scannerXENTRY or equivalent (Foxwell NT530 MB, Autel MS906). Reset adaptation values and perform basic settings drive cycle.
16. Test drive 20-30 minutes, mixed drivingSeveral full-throttle shifts and a few coasting downshifts to relearn shift points. Re-scan for codes.
17. Log the serviceDate, mileage, 8-9 quarts ATF 134 FE, filter kit P/N. Next service +60,000 miles.

✅ After You Finish - Verify Checklist

• No tools left in the engine bay or under the car
• All plugs torqued to spec with new crush washers / gaskets
• Test the system worked on (start, drive, monitor for codes)
• Look for leaks or drips after 30 minutes of cool-down
• Record date, mileage, fluid P/N, and quantity in your service log
• Properly dispose of old fluid at an auto parts store recycling center

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❓ Frequently Asked Questions