Grooved Ball Bearing / Crankcase - Stihl TS 420 Manual

: Insert the screws (arrows) and
tighten them down crosswise.
– Tightening torques, b 3.5.
1
– Coat the needle bearing (1) with
oil.
: Slide the needle bearing (1) into
the small end.
– Examine and install the piston,
b 7.7.
– Examine and install the cylinder,
b 7.5.
– Reassemble remaining parts in
reverse order.
46
7.6.2 Grooved ball
bearing / crankcase
The two halves of the crankcase
can be replaced individually if they
are defective.
New crankcases are delivered with
the relevant components pre-
assembled – see spare parts list.
Those parts which are not supplied
with the new crankcase must be
removed from the old crankcase,
examined and replaced if
necessary.
When fitting a new crankcase, the
machine's serial number must be
stamped on the crankcase with
2.5 mm figure stamps.
If the original crankcase is reused,
the oil seals and grooved ball
bearings must be replaced, all
gasket residues removed and the
mating surfaces cleaned
thoroughly. The mating surfaces
must be absolutely clean to
guarantee a perfect seal.
Examine both halves of the
crankcase for cracks and check all
mating surfaces for signs of
damage.
– Refer also to troubleshooting,
b 4.6.
– Remove the crankshaft,
b 7.6.1.
– Wear protective gloves – risk of
burns.
Ignition-side half of the
crankcase
: Carefully drive the oil seal out
with a suitable punch.
: Examine and clean the
crankcase, replace if necessary.
Fit new grooved ball bearings if the
crankcase is in good condition.
1
– Heat the area around the bearing
seat to approx. 150 °C (300 °F).
The bearing (1) drops out of its own
accord when this temperature is
reached.
TS 410, TS 420