Flywheel Housing, Flywheel And Backplate - Westerbeke WPDS-20 Technical Manual

Al6
FLYWHEEL HOUSING, FLYWHEEL AND BACKPLATE
Removing
1. Take weight off rear of engine with sling attached to rear lifting eye.
2. Remove rear mounting brackets from transmission housing.
3. Remove nut securing each rear mounting bracket to flexible mount.
4. Close inlet and outlet sea water cocks. Disconnect raw water from transmission
oil cooler (hose between oil cooler and heat exchanger).
5. Disconnect battery cable leads from starter motor.
6. Disconnect shaft cable or rod and clips from transmission shift lever.
7. Disconnect coupling between transmission and propeller shaft and move shaft
back approximately four inches.
8. Remove bolts and lock washers securing transmission to bellhousing. Pull
transmission straight back and filt away from engine.
9. Remove Starter Motor.
10. Remove Flywheel Housing. Remove bolts and lock washers (front of housing
and rear of backplate) securing housing to backplate. Pull housing from the
backplate two locating dowels.
11. Remove Damper Plate. (Hydraulic Transmission) Remove the socket head
screws securing damper plate to flywheel.
12. Remove Flywheel. (Hydraulic Transmission) Knock-up the tabs of the star
washer and remove the bolts securing flywheel to the cranksh . .ift. Pull flywheel
from crankshaft.
13. Remove Gear Drive Plate and Flywheel. (Manual Transmission) Knock-up the
tabs of the star washer and remove bolts securing drive plate and flywheel to the
crankshaft. Remove star washer. Pull drive gear and flywheel from crankshaft.
14. Remove Backplate. Remove bolts and lock washers securing backplate to cylinder
block and pull backplate from the cylinder block two locating dowels.
15. Remove gasket from cylinder block face.
16. Remove oil seal (if damaged, pressed fit).
To View and Overhaul
Examine the flywheel starter ring gear teeth for damage or wear, and replace ring
gear if required. The fitting of a new ring requires special workshop equipment for
heating the ring evenly to shrink
it
onto the flywheel. With special workshop equip-
ment available proceed as follows:
17(a). Place the flywheel in a suitable container of clean cold water and support
the assembly in the container by positioning four metal blocks under the ring gear.
Arrange the flywheel assembly so that it is partly submerged in water with the ring
gear uppermost. The complete ring must be above the water line and i-es recom-
mended that the bottom face of the ring be approximately 1/4 in. above water level.
Heat the ring gear evenly around its circumference using oxy- acetylene welding
equipment, thus expanding the ring, whi.ch will allow the flywheel to drop away from
the ring gear. Lift out the ring gear and completely dry it off.
(b) Ensure that the face of the flywheel and new ring gear are clean and free from
burrs.
(c)
Heat the new ring gear to the approximate temperature, refer to "General Data".
Fit the ring gear over tlle flywheel with the lead in on the teeth facing the front of the
flywheel and allow the ring to cool at room temperature.
18. Clean the face of the cylinder block, crankshaft, backplate, flywheel housing and
flywheel.
19. Check that the two locating dowels in the cylinder block face are free from burrs.