Catalytic Converter - Support Modification

90bmw13 Group 18 Exhaust System
Bulletin Number 18 02 89 (1933)
Woodcliff Lake, NJ June 1990 Service Engineering
This Service Information Bulletin supersedes S.I. 18 02 89 (1933) dated November 1989. It lists revised information about the catalyst assembly.

Please remove and discard S.I. 18 02 89 (1933) dated November 1989 from your S.I. binder.

SUBJECT: Catalytic Converter Support

MODELS: M5, M6



Situation: To eliminate tension between the catalyst attachment flange and the exhaust hanger, BMW Motorsport has developed an improved catalyst support for the M5/M6 exhaust system.

The improvement involves the use of a bushing presently used in the assembly of the M3 exhaust system.

Implementation: Whenever the M5/M6 Catalyst assembly is found to be defective and requires replacement, use the procedure listed below.

Procedure: ^ Replace catalyst assembly per Group 18 of the Repair Manual.

^ Measure the gap between the hanger and the side attachment flange.

^ Loosen the exhaust hanger from the rear of the transmission.

^ If the gap is less than 5 mm, install one M3 bushing (P/N 18 20 1 309 043) as shown in the attachment.

^ If the gap is greater than 5 mm, install two M3 bushings.

^ Tighten the exhaust hanger without tension or strain (bend outboard end if necessary).
^ Due to the thickness of the M3 bushing it will be necessary to install a longer attaching bolt.

One bushing P/N 07 11 9 913 657 (M8 x 25) bolt

Two bushings P/N 07 11 9 913 662 (M8 x 30) bolt

^ Install an exhaust locking nut (P/N 11 62 1 711 954) above the exhaust hanger welded nut and tighten securely (see attachment).

Parts
Information: Description Part Number Qty

M3 Bushing 18 20 1 309 043 X

M8 x 25 Bolt 07 11 9 913 657 X

M8 x 30 Bolt 07 11 9 913 662 X

M8 Lock Nut 11 62 1 711 954 1


Warranty
Information: 1. These additional parts are reimbursable under the terms and provisions of the BMW 5 Year/50,000 Mile Emissions Warranty when replacing a defective Catalytic Converter.

2. Usage of any of the above parts are to be included on the Warranty Claim for the defective Catalytic Converter.

Defect code: 11 77 00__00 Catalytic Converter
01 Split
13 Broken (Monolith)
39 Causing Noise
48 Leaking (Joint/Manifold)
49 Leaking (Compensator)
80 Burnt Out

3. Labor for installation of above listed parts is included in the labor operation for replacing a Catalytic Converter.

Labor operation: 18 32 005

Labor allowance: 12 FRU

Any questions regarding warranty coverage should be discussed with your District Service Manager.