10.1 Replacing the external filter
1. Loosen the outer filter 6 using a belt wrench and remove it (figure 1.18).
Figure 1.18. Replacing the external filter.
2. Lubricate the rubber filter sealing ring with oil.
3. Screw in the new filter until the rubber sealing ring touches the filter head. Then tighten it 3/4 of a turn.
4. If the oil in the automatic transmission is not changed, the external filter must be filled with the drained oil. Then you need to adjust the oil level in the automatic transmission.
Information copied from the website: MercedesMAN
5. Start the engine.
6. Open the oil level indicator cover and remove it.
7. Check and adjust the oil level in the automatic transmission.
8. Insert the funnel into the hole under the oil level indicator.
9. Slowly pour oil into the automatic transmission, while the engine should be running at idle speed.
Volume of transmission oil in automatic transmission 723/345/346/348: first filling - 15.0 l, replacement 12.5 l.
10. Check the tightness of the outer filter.
10.2. Changing oil and filter
1. Wipe the surface around the drain plug 1 on the pan and radiator 5 (figure 1.19a, b).
Figure 1.19a. Wipe the surface around the drain plug 1 on the tray... 1 - Drain plug, 2 - Nut.
2. Unscrew drain plugs 1 and 5 and loosen the drain bolt at the top of the radiator.
3. Screw in the drain plugs. Tighten the drain bolt at the top of the radiator.
Figure 1.196. ... and radiator 5.
4. Wipe the surface around nut 2 on the oil filler pipe (figure 1.19a).
5. Unscrew the oil filler pipe.
6. Remove the automatic transmission pan. When removing it, be careful, it is still filled with transmission oil. Replace the gasket.
7. Remove oil filter 3 and inlet pipe 4 (figure 1.19c).
Figure 1.19c. Remove oil filter 3 and inlet pipe 4.
8. Replace the rubber seal on the intake pipe and lubricate it with oil.
9. Install the inlet pipe 4 and the new filter 3.
10. Install the tray.
11. Screw in the oil filler pipe.
12. Replace the outer filter 6 (figure 1.18).
13. Open the oil level indicator cover 7 and remove it (figure 1.19g).
14. Insert the funnel into the hole under the oil level indicator.
Figure 1.19g. Open the oil level indicator cover 7 and remove it: 8 - Retainer.
15. First pour in about 10 liters of oil.
16. Start the engine.
17. Move the gear selector lever through all positions in turn, then set it to the "N" position.
18. Slowly pour oil into the automatic transmission, while the engine should be running at idle speed. When the automatic transmission is cold (20-30°C), the oil level should be between the "min" and "max" marks of range B (figure 1.19d). When the automatic transmission is warmed up (70-90°C), the oil level should be between the "min" and "max" marks of range A.
19. Insert the oil level indicator.
20. Check the tightening torque of the oil pan, filter and oil cooler bolts.
Figure 1.1 9d. When the automatic transmission is cold (20-30°C), the oil level should be between the "min" and "max" marks of range B. When the automatic transmission is warmed up (70-90°C), the oil level should be between the "min" and "max" marks of range A.