REPAIR INSTRUCTIONS, PART 1
Page 313
Crankshaft Hub Installation
[212 RH]
INSPECTION
Inspect the bore of the crankshaft hub for scoring.
Also, check the condition of the hub flange and
the threaded holes.
Replace the hub if the crankshaft seal lip has
made a significant wear groove on the outer
diameter of the hub. Mack Trucks, Inc. DOES
NOT recommend the use of a service sleeve to
repair this type of hub damage. Also, if there is
any galling, scoring or fretting on the inner
diameter, replace the hub.
INSTALLATION PROCEDURE
Refer to Figure 360.
1. Using a suitable grease-type lubricant, coat
the working surface of the seal in
preparation for installation of the crankshaft
hub.
Teflon
®
-type seals do not require greasing the
working surface of the seal.
2. Heat the hub to approximately 250°F
(121°C) prior to installation.
3. Using heat-resistant gloves, position the hub
on the crankshaft.
While the crankshaft has a keyway slot, the
crankshaft hub does not. Timing is set in relation
to the flywheel position and not the crankshaft
hub, eliminating the need for a hub key and
precise alignment.
4. In a quick, even motion, push the hub onto
the crankshaft.
5. Install the hub washer and capscrew.
Tighten the capscrew to the specified
torque, 360 lb-ft (490 N폷m), using torque
wrench J 23775-01, or equivalent.
360
Figure 360 — Crankshaft Hub/Vibration Damper
Vibration Damper Installation
[212 RB]
INSPECTION
When removing or handling the vibration damper,
be careful not to damage the housing. Any dents
in the outer housing may render the damper
ineffective and result in cracks in the crankshaft.
The vibration damper cannot be repaired.
Inspect the vibration damper for dents, nicks or
fluid leaks in the outer housing. If any of the
above are evident, the vibration damper must be
replaced. Due to the close clearances between
the damper housing and its internal flywheel,
dents or nicks may cause contact between the
two components. Fluid loss will deteriorate the
dampening effect of the damper.
1. Crankshaft
2. Crankshaft Hub
3. Vibration Damper
4. Pulley
5. Damper/Puller
Capscrews and Washers
6. Hub Capscrew
5-111.bk Page 313 Monday, July 10, 2006 2:26 PM
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