267319 Removing and Installing (Main) Catalytic Converter on 4.8-Litre V8 DFI Engines
WM 267319 Removing and installing (main) catalytic converter on 4.8-litre V8 DFI engines
Technical values
Preliminary work
1. Remove engine guard. -> 108019 Removing and installing engine guard (underbody panel) on DFI engines - section on "Removing" 108019 Removing and installing engine guard (underbody panelling)
Removing (main) catalytic converter
Removing main catalytic converter on cylinder bank 1 to 4 (right)
CAUTION
Danger of burns from hot exhaust system
-> Do not remove the exhaust system until it has cooled down.
-> Wear protective gloves.
Main catalytic converters
1. Remove the transverse strut. Remove screws -arrows- (don't forget the centre screw.).
Transverse strut
2. Remove the cardan shaft between the front-wheel drive and transfer gear -see Figure-. -> 390219 Removing and installing front cardan shaft - section on "Removing" 390219 Removing and installing front cardan shaft
Cardan shaft between front-wheel drive and transfer gear
3. Release the connecting clamps between the catalytic converters and the exhaust system. Then slide the clamps backwards onto the exhaust system => Clamps securing catalytic converter to exhaust system. The exhaust clamps must not be used again.
Clamps securing catalytic converter to exhaust system
4. Loosen the catalytic converter holders on the body and on the transmission support (two screws on each). => Fastening screws on body and cross member
Fastening screws on body and cross member
5. Support the transmission with a transmission jack. Remove transmission support. -> 343800 Removing and installing transmission support - section on "Removing"
6. Carefully allow the main catalytic converter to hang down. Unscrew the three connecting nuts between the primary and main catalytic converters -arrows-. Remove the main catalytic converter. Remove the flange gasket.
Connecting nuts between primary and main catalytic converters
Information
- If the working height of the vehicle has to be changed due to further work, the transmission support must be re-fitted using the old bolts.
7. Refit the transmission cross member using the old screws so that you can remove the transmission jack from under the vehicle.
Removing main catalytic converter on cylinder bank 5 to 8
CAUTION
Danger of burns from hot exhaust system
-> Do not remove the exhaust system until it has cooled down.
-> Wear protective gloves.
Main catalytic converters
1. Remove the transverse strut. Remove screws -arrows- (don't forget the centre screw.).
Transverse strut
2. Release the connecting clamps between the catalytic converters and the exhaust system. Then slide the clamps backwards onto the exhaust system => Clamps securing catalytic converter to exhaust system. The exhaust clamps must not be used again.
Clamps securing catalytic converter to exhaust system
3. Loosen the catalytic converter holders on the body and on the cross member (two screws on each). -arrows-
Fastening screws to body and cross member
4. Carefully allow the main catalytic converter to hang down. Unscrew the three connecting nuts -arrows- between the primary and main catalytic converters and remove the main catalytic converter. Remove the flange gasket.
Nuts connecting primary and main catalytic converters
Installing (main) catalytic converter
Installing main catalytic converter on cylinder bank 1 to 4
Main catalytic converters
1. Transmission cross member is removed and supported with the jack.
Information
- Gaskets and self-locking nuts and bolts must always be replaced.
2. Slide a new exhaust clamp onto the exhaust pipe.
3. Ensure sealing faces of exhaust system are clean.
4. Replace flange gasket and push over the studs of the main catalytic converter.
5. Move main catalytic converter into installation position and fit new nuts and bolts.
6. Tighten nuts between the primary and main catalytic converters to the specified tightening torque. => Tightening torque: 23 Nm (17 ftlb.)
Information
- To fit the cardan shaft, the transmission must be supported again and the transmission support removed. Then fit the transmission support with new screws. -> 390219 Removing and installing front cardan shaft - section on "installing" 390219 Removing and installing front cardan shaft
7. Re-install the cardan shaft between the front-wheel drive and transfer gear. When doing so, make sure that the main catalytic converter is also positioned above the transmission cross member along with the cardan shaft.-> 390219 Removing and installing front cardan shaft - section on "Installing" 390219 Removing and installing front cardan shaft
Cardan shaft between front-wheel drive and transfer gear
8. Tighten the screws used to secure the catalytic converters to the body and transmission support to the specified tightening torque. => Tightening torque: 23 Nm (17 ftlb.)
9. Fit the exhaust clamps. For details of installation position and tightening torque, see -> 260119 Removing and installing exhaust system on DFI engines - section on "Installing" Service and Repair.
10. Install the transverse strut. Screw in screws -arrows- (don't forget the centre screw.). => Tightening torque: 10 Nm (7.5 ftlb.)
Transverse strut
Installing main catalytic converter on cylinder bank 5 to 8
Main catalytic converters
1. Push new exhaust clamp onto exhaust pipe.
2. Ensure sealing faces of exhaust system are clean.
3. Replace flange gasket and push over the studs of the main catalytic converter.
4. Move main catalytic converter into installation position and fit new nuts and bolts.
5. Tighten nuts between the primary and main catalytic converters to the specified tightening torque. => Tightening torque: 23 Nm (17 ftlb.)
6. Tighten the screws used to secure the catalytic converters to the body and cross member to the specified tightening torque. => Tightening torque: 23 Nm (17 ftlb.)
7. Fit the exhaust clamps. For details of installation position and tightening torque, see -> 260119 Removing and installing exhaust system on DFI engines - section on "Installing" Service and Repair.
8. Install the transverse strut. Screw in screws -arrows- (don't forget the centre screw.). => Tightening torque: 10 Nm (7.5 ftlb.)
Transverse strut
Subsequent work
1. Install engine guard. -> 108019 Removing and installing engine guard (underbody panel) on DFI engines - section on "Installing" 108019 Removing and installing engine guard (underbody panelling)