Removing and Installing (Main) Catalytic Converter

Removing And Installing (Main) Catalytic Converter On 4.8-litre V8 DFI Engines

Technical Values







Preliminary work
1. Remove engine guard.

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.












1. Remove the transverse strut. Remove screws -arrows- (don't forget the centre screw.).







2. Remove the cardan shaft between the front-wheel drive and transfer gear -see Figure-.







3. Release the connecting clamps between the catalytic converters and the exhaust system. Then slide the clamps backwards onto the exhaust system.







4. Loosen the catalytic converter holders on the body and on the transmission support (two screws on each).
5. Support the transmission with a transmission jack. Remove transmission support.







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.

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.












1. Remove the transverse strut. Remove screws -arrows- (don't forget the centre screw.).







2. Release the connecting clamps between the catalytic converters and the exhaust system. Then slide the clamps backwards onto the exhaust system.







3. Loosen the catalytic converter holders on the body and on the cross member (two screws on each). -arrows-







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.

Installing (main) catalytic converter

Installing main catalytic converter on cylinder bank 1 to 4







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.







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.
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,







10. Install the transverse strut. Screw in screws -arrows- (don't forget the centre screw.). - Tightening torque: 10 Nm (7.5 ftlb.)

Installing main catalytic converter on cylinder bank 5 to 8







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.







8. Install the transverse strut. Screw in screws -arrows- (don t forget the centre screw.). - Tightening torque: 10 Nm (7.5 ftlb.)

Subsequent work:
1. Install engine guard.