Driveshaft - Vibration or Noise Troubleshooting Chart
87BMW01GROUP 26 Driveshaft -
Bulletin Number 26 02 84 (895) Page 1 of 3
Montvale, NJ July 1987 Technical Dept.
This Service Information Bulletin supersedes S.I. 26 02 84 (895) dated January 1986. It lists new specifications for the center bearing preload on the E32. Also refer to S.I. 26 01 87 (1421).
Please remove and discard S.I.. 26 02 84 (895) dated January 1986 from your S.I. binder.
SUBJECT: Driveshaft Noise and Vibration
MODELS: All
Complaint: Vibration or noise while driving.
Cause: Change in operating position. The condition and installed position of a driveshaft as well as its handling during installation are very important to assure driving without noise and vibration.
Correction: The attached Troubleshooting Chart with corrective measures will help you in dealing with customer complaints. Please note in particular the checking and possible correcting of the deflection angles with Special Tool 88 88 6 261 030 and the torquing of the threaded sleeve with Special Tool 88 88 6 261 040. (A straightedge is required to measure the engine and final drive angles in BMW 524td cars - see Repair Manual.)
After determining the vertical installed position (deflection angle correction), the horizontal installed position of the driveshaft must also be checked. If applicable, the installed position of the engine/transmission assembly must be changed according to test results. Loosen engine mounts to avoid stress. Loosen transmission mounts and correct the installed position to the left or right - see Repair Manual.
Tighten engine and transmission mounts again - refer to Technical Data for tightening values.
Center bearing preload for all models except E32: 4 to 6 mm in forward direction. Center bearing preload for E32 only: 2 to 4 mm in forward direction.
Procedures: Mandatory for all work on driveshafts
1. Unscrew threaded sleeve (where applicable) and check slide for perfect length compensation and easy movement, replacing clamping ring if necessary. Clean slide and lubricate with multi-purpose grease that meets NLGI class 2 specifications.
2. Hold threaded sleeve (applies to all but E32) with Special Tool 88 88 6 261 040 only after installation of driveshaft.
Tightening torque for all models: 22 N-m/16 ft.lbs.
3. When removing and installing the manual transmission, detach the driveshaft on the transmission end, then unbolt the center mount and hold the driveshaft with suitable suspension (also refer to S.I. 26 02 87 (1438)). Note point 2 when reinstalling! When removing and installing the final drive, detach and hold the driveshaft in such a manner that the car could still be pushed if necessary. Never let driveshaft sections drop down, because this would damage the needle bearings in the universal joint. Note point 2 when reinstalling!
4. Before removing the driveshaft, mark installed position at the transmission and final drive flanges. Also mark the driveshaft sections before pulling them apart. If this has been forgotten, connect the sections so that the universal joint forks are in the same plane (balanced state). Turn the propellor shaft sections 180~ if vibration occurs afterwards.
5. The cementing of driveshaft sections on the slide with Loctite, is no longer approved!
Information: The following procedures will help in finding and eliminating the cause of driveshaft problems. Refer to S.I. 33 03 87 (1430), if it is necessary to run a car on a lift with the wheels spinning.
a. Speed up engine in a stopped car and check whether the problem is from the engine side.
b. Test drive car in the concerned speed range and check whether the problem is engine speed or road speed dependent.
c. The axle half shafts could be disconnected at the final drive to determine whether the causes for vibration are to be found on the driveshaft or wheel end. The engine must be run at that speed and in that gear or selector lever position where the vibration occurs. See the attached Troubleshooting Chart if the same vibrations occur. If there is no vibration, the cause will be found in the runout of the half shafts or wheels.
TROUBLESHOOTING DRIVESHAFT
Miscellaneous:
When checking "sticking of universal joints", remember that the universal joint moves only in relatively small angular deviations while driving. Consequently checking is only required in this motion range, whereby pertinent "feeling" and experience are advantageous for correct evaluation. Note in so doing that the universal joint must have smooth, easy movement (without considerable play - max. 0.15 mm) from thp"zero or off position" as well as through the mentioned motion range.
Whether or not transmission and final drive flanges can be reused will depend on the condition of the flange bolt bores (worn?) as well as axial and radial runout.
Axial runout: transmission/flange max. 0.10 mm
Radial runout: transmission/flange max. 0.07 mm final drive/flange max. 0.07 mm*
* Measured at driveshaft centering lip.
Experience in the past has shown that in many cases off-setting the driveshaft flange to the final drive flange by 90~, 180~ or 270~ will provide improved driveshaft running.
Repair Manual and Technical Data microfiche will be corrected or supplemented accordingly in the next editions.