BMW 1989-1995 525i Service Manual page 229

Clutch, inspecting and installing
CLUTCH
WARNING -
Always use new pressure plate mounting bolts.
210-5
An alignment tool (clutch pilot tool) should b e used to center
the clutch disc to the pressure plate. Always use new clutc h
pressure plate bolts when installing the press ure plate to the
flywheel.
1. Inspect clutch pressure plate for wear or damage. Re·
place pressure plate if any faults are found.
• loose rivets
• bent or misaligned release levers.
• warped. cracked or scored friction surface
NO TE -
New pressure plates are normally coated with
a
cotro -
sion inhibitor for storage. Use
a
grease-Iree solvent to
clean the Iriction surface 01 new pressure plates belore
installation.
2. Clean flywheel friction surface and inspect it for wear,
cracks , and scoring. Check for loose or worn guide
pins. Replace flywheel if any faults are found.
3. Check clutch disc thicknes s, runout, and general con-
dition. Check friction surface for oil contaminat ion. Re-
place clutch disc if any faults are found .
Clutch Disc
• Clutch disc runout (max.) 0.50 mm (0.020 in.)
• Clutch disc thickness (min.) 7.5 mm (0.295 in.)
4. Clean release bearing guide sleeve on transmissi on.
Clean input shaft splines.
5. Inspect the splines of the clutch disc and the transmis-
sion input shaft. Check that the clutch disc slides freely
on the shaft.
6. Inspect clutch release bearing for smooth operation.
Check for wear on bearing and lever contact surfaces.
Check the release lever pivot pin for wear. Replace
worn parts.
NOTE -
On 6-speed transmissions. the release lever spring clip
and the release lever pivot pin should a lways be re-
placed.
7. Check grooved input shaft ball bearing in crankshaft
center. Replace bearing if it does not rotate smoothly.
8. Assemble clutch disc and pressure pla te assembly to
flywheel. Thread new pressure plates bolts in hand
tight.
NOTE -
• Make sure the pressure plate is aligned on the fly-
wheel guide pins.
• Be sure the clutch disc is installed correctly. The new
disc should be marked with "engine side" and "trans-
mission side ".
9. Center clutch disc to crankshaft using a clutch pilot tool.
Tighten pressure plate mounting bolts evenly until disc
is firmly held in place.
10. Remove the centering tool and finish torquing the bolts
in a uniform pattern.
Tightening Torques
• Flywheel to crankshaft
(use new bolts) 105 Nm (77 It-lb)
• Pressure plate to flywheel (use new bolts)
8.8 grade 24 Nm (18 tt-lb)
10.9 grade 34 Nm (25 ft·lb)
NOTE-
• Boll grade is marked on the boll head.
11 . Lightly lubricate clutch disc splines and transmission
input shaft splines.
CAUTlON-
BMW recommends using
a
light coat 01 Microlube
GL 261 on the clutch disc and ttensmission input
shaft splines.
12. Lightly grease release lever bearing contact points.
See Fig. 7. Install release lever.
13. Install release bearing, making sure bearing tabs are
flush against the release lever. See Fig. 8. See note for
special installation instructions.
NO TE-
Two types 01 the release bearings have been installed
on the cars covered by this manual. 1992 and teter cars
and all replacement bearings Irom BM W have
a
plastic
guide sleeve. No lubrication should be used on the
plastic guide sleeve during inslallation. Earlier style
bearings with an aluminum guide sleeve should be
lightly lubricated with molybdenum disulfide grease
(Molykote Longterm 2
or equivalent).
14. Remove flywheel holding fixture and reinstall transmis-
sion. See 230 Manual Transmission.
CLUTCH MECHANICAL