M/T - Noise at Idle and Low Speed

GROUP 21
Clutch

Bulletin Number
21 02 84

Montvale, NJ
December 1986
Technical Dept.

This Service Information Bulletin supersedes S.I. 21 02 84 (923) dated March 1985. It updates the Parts List to include longer flywheel bolts for the 318i model.

Please remove and discard S.I. 21 02 84 (932) dated March 1985 from your S.I. binder.

SUBJECT:
Manual Transmission Noise at Idle & Low Speed

MODELS:
318i (All years)
533i, 6 = Si & 733i (All vehicles produced prior to 3/84)

Problem:
Customer complaints relative to the following:

1. Rattling and/or chattering of manual transmission at idle speed.

2. Rattling noise from manual transmission when accelerating from low speed range.

3. Rattling noise while driving constantly at low engine speed (less than 1800 rpm).

Cause:
The combustion process in the engine and the torsional harmonics associated with low speed ranges produces irregular variations in the rotation of the transmission components.

Customer Relations Information:
We must point out that these customer complaints are to be regarded as comfort impairing. Under no circumstances should they be considered as technical defects.

1. Check adjustment of engine idle speed against values in pertinent technical data.

2. Increase RPM to approximately 1200 RPM and check for rattling.

3. Accelerate car in 4th gear from approximately 1500 to approximately 2000 RPM (with engine at operating temperature) and check for rattling.

Solution:
If a rattling noise is no longer heard after reaching the higher speeds, the parts listed in can be installed.

Note:
Repair procedures must be worked out in advance with the responsible District Service Manager (NO EXCEPTIONS).

Installtion:
In conjunction with the listed conversion parts, the external shift parts must be installed according to the instructions in Service Information Bulletin 25 01 83 (804), if the cars have not already been equipped with them at the factory.





Warranty Status: