Fitting Screws; Mounting Thread Plugs - Husqvarna Automower 310 Technical Manual

5.23 Fitting Screws

It is extremely important how screws are mounted in plastic.
If the screws are mounted incorrectly, there is a risk of
damaging the threads in the plastic and thereby shortening
the service life of the plastic part. If threads have been
destroyed, the part must be replaced.
Important information
If the tightening torque specified in 5.24 Bolt Fasteners
cannot be attained due to e.g. the threads in plastic being
destroyed, this must be rectified by inserting thread plugs
or replacing the whole part. If this is not done, a satisfactory
seal or function will not be attained.
To ensure the threads in plastic parts are not damaged:
1. Start by carefully turning the screw counter-
clockwise until it engages the existing threads in
the plastic.
2. The screw will fall slightly by itself when the threads
are located correctly in relation to the existing
threads in the plastic.
3. Now screw in the screw to the correct torque as
specified in 5.22 Screw Fasteners
For assembling larger parts in plastic, such as the top of
the chassis, it is important that the screws are tightened
crosswise. This is to avoid tension in the part, causing
malfunction or not attaining a seal.

5.24 Mounting thread plugs

If the threads in plastic parts are worn, thread plugs can be
inserted. A repair kit containing thread plugs and suitable
metal screws is available to order, refer to the current spare
parts list for the part number. As the diameter of the screw
bosses on chassis is not adapted to accept thread plugs,
the plugs must be fitted extremely carefully. There is a risk
that the screw bosses crack as the goods is thin. However,
it is worth trying if the plastic threads are worn as the
alternative is to replace the entire chassis.
To mount a thread plug into a worn plastic thread:
1. Make the hole bigger with a 6,6 mm / 0.24 " drill to
a depth corresponding with the plug.
2. Screw in the thread plug with the screw that comes
with the repair kit and screwdriver. NB! Tighten by
hand so as not to damage the plastic.
3. Make sure the plug is screwed in completely so
that a good seal is obtained.
4. Fit the plastic parts with the accompanying M5
screw instead of the old plastic screw.
English - 78
TH_1158203_310_315_GARDENA_US.indd 78
5. REPAIR INSTRUCTIONS
1
½
2 3
1
ø 6,6 mm / 0.24"
3
2
4
2016-05-11 10:16:43